The Selene Project

[sts-200]

The Second Selene Project

Sept-68
The first full session of the Selene Board is held in Paris.
Several resolutions are "rubber stamped", including the old SPC’s plan to reduce the number of flight tests and delay development of systems related to the 3 launch long duration lunar missions. Annual reports into the progress and finances of the Project will be produced and submitted to national governments as part of future budget rounds.
An additional item is the suspension of further Explorateur flights, and the formation of an international team to investigate the failures.

Australia formally joins the Selene Project on the 16th September, symbolised with an event at Rainbow Beach. Prime Minister John Gorton ceremonially breaks ground on Launch Pad No.8, a facility that will ultimately be used to launch Constellation rockets. Australia is providing all of the funds to build the new pad and its associated assembly facilities.
Australian contributions to the Project will primarily be in the form of ground support, training and in the operation of facilities such as Rainbow Beach. In return, research and results from across the Project will be made available and two Australian astronauts will be trained to fly on Aurora or early Selene test flights. The Selene Board will now increase to 18 members, formally joined by two Australians with engineering and legal backgrounds.

Flight schedules and plans for the upcoming Aurora flights are released as part of an effort to reassure the public that the Selene Project is still making progress.
-Two unmanned tests of the PROM (Aurora 2A and Aurora 3) will be flown this year.
-Aurora 4, the first manned flight, will conduct orbital manoeuvers and test navigation and control equipment during a 3 day flight in February.
-Aurora 5 will be the first to be equipped with the large main propulsion engine and will conduct more extensive manoeuvres, including an experimental rendezvous with its booster core and a spacewalk.
-Aurora 6 will repeat Aurora 5's mission.
-Aurora 7 will test the PROM on a 10 day flight and will boost itself up to a higher orbit to test deep space navigation techniques and make a faster re-entry.
-Auroras 8-12 will be flown in 1970 using PROM/VDL-B vehicles (an Earth orbit test version of the lander module that will have life support, power and crew accommodation, but will not be equipped with all the systems such as landing legs or engines). These flights will test the crews on longer missions, make spacewalks, try out navigation techniques and verify the performance of many of the new VDL systems.
-Two further Earth orbit flights, Auroras 13 and 14, are being planned for 1971 or 72 to test the complete PROM/VDL-C lander. If schedules are met, Aurora 14 should be the first to fly on a Constellation rocket.


Hermes-A1 / SSLV-7
Australian TV relay satellite launched from Rainbow Beach. It is the first “3 burn” mission, now allowed thanks to the new J-650-100 engine. With a desire for a long orbital life, the satellite's fuel load has been increased to 525kg, for a total launch mass of 3,455kg. A parking orbit of 202x213km km is achieved at T+0:10:21. At T+0:24:31 the engine reignites to move to a 252x35,626km transfer orbit. The lower initial inclination allowed by the new 3 burn profile reduces the velocity change needed on the final burn. This, combined with increased confidence in the performance of the rocket, allows for the increase in payload. A 35625x35925km final orbit is achieved, with the satellite and its upper stage setting a new record for the heaviest payload injected into geostationary orbit [a record that stands for 36 years].
On 6th October, the satellite’s transceivers are ready and for the first time, TV signals can be received in every part of the Australian continent (although areas outside of the south and east need larger, better receiver equipment to detect the signal).
After an early turbogenerator failure, the satellite performs well. By January 1974, two more units have failed and plans are made to retire the satellite. A fourth failure in June '74 brings national TV relay operations to a halt. The satellite is moved to a higher orbit in July and is switched off. Controllers estimate it still had sufficient fuel for another 3 years of operation.


Oct-68
The first of a new series of Lunar Landing Development Vehicle test flights are completed at Farnborough. During a break before the next series of tests, Westland engineers are allowed to make temporary changes to the control system. The modified Wessex becomes the first helicopter ever to make a fully automatic landing.

Oct-68 Overseas
NASA's Apollo 8 makes an 8 day flight. Originally scheduled as the first of the Space Laboratory flights, the mission has been repurposed to test spacewalking "EVA" techniques due to delays in the Lab programme.
The crew of three make three spacewalks. The first sees astronaut Edwin “Buzz” Aldrin going outside to test a new liquid cooled garment worn under his suit. The test is a success as Aldrin reports that he does not become unduly overheated, even during carefully planned periods of vigorous physical activity in full sunlight. The second walk is less successful as Aldrin tests a cold gas "jet belt". Still tethered to the Apollo, he finds it impossible to control his movements using the belt. On the final EVA Aldrin is joined by veteran spacewalker John Young. They make the first ever two-man EVA, the first live TV broadcast of a spacewalk and co-operate in several tasks at a "work station" set up on the Service Module.


Oct-68
Aurora 2A / S-110
Unmanned test of the PROM spacecraft. The spacecraft operates successfully in orbit but the RM crashes on landing when the capsule’s parachute fail to deploy properly. The loss of Aurora 2A brings much of the operations side of the Selene Project to a sharp halt. Development and integration of both Aurora and Explorateur spacecraft is now on hold while investigations into both programmes are under way.

A broadly receptive audience at a union meeting in Yorkshire listens to a speech on how the nation is "wasting" money on huge projects such as Selene, while many ordinary workers are left to suffer under the poor management and exploitative working conditions that are “normal” in private industry.
The audience seems to be soured by a few poor jokes about parachutes and turns hostile after negative comments over the quality of the (British) engineering. Things go from bad to worse when the speaker suggests that Britain should cooperate with the Soviet Union in the peaceful exploration of space. He is jeered off the platform by his own members.


Nov-68
Accounts from union members at the recent meeting are seized upon by the Sunday papers.
Stories range from "Union Plot to Give Moon to Soviets" with a (completely unrelated) editorial on how missile secrets are being betrayed to the Soviets, to the somewhat more factual "Union Members halt Criticism of Selene Project", with a dull story buried in the back pages.
Almost all the published accounts focus on the discussion over Selene (the controversial project does sell newspapers) and miss the reality that the audience simply objected to being told what to think by a closet communist. Several interviews after the event show that the members present neither support Selene nor are they particularly against it, with most prepared to grudgingly agree that it is "summ't as got 'erby done".
Nevertheless, the exaggerated press reports, a series of “Chinese whispers” and a fear of a backlash from their own members leads many prominent figures of the labour movement to avoid any overt criticism of the Selene Project for some years to come. It seems The Project is more popular than many had realised.


Lunar Orbiter A7 / BSLV-18
Narrow Angle Orbiter with improved propulsion system and "context" camera, which provides a small (16mm) Wide Angle image co-projected into a corner of the main 70mm film frames. Launch vehicle and spacecraft performance is good and a fast translunar trajectory is achieved.
Only one course correction is needed at T+24:17. A 67s LOI burn is made at T+84:40 to a 144x712km lunar orbit. An 8.2s burn 3 orbits later takes this to 144x150km. Photography begins at T+96:25, but to everyone’s frustration the film jams after just 68 orbits, with 116 frames exposed.
The film is cut after attempts to un-jam the system fail. All 116 frames are radioed back successfully. 70% of the primary mission was completed, including at least some pictures of 5 of the 6 possible landing sites in the mission plan. Later images were intended to be farside and polar studies.
The spacecraft remains operational and is used to test the engine modifications and continue radio tracking of its orbit to improve models of the lunar gravity field. The orbital inclination is raised to 68deg on day 18, depleting the remaining fuel.
The spacecraft is tracked until it hits the lunar surface 78 days after entering orbit.


A Top Secret report into the failure of the Blue Streak OTR-21 test earlier in the year is cause for considerable concern to the British government. Evidence of metal fatigue was found in pieces of the engines and fuel lines recovered from the crash. A quick inspection of Blue Streak missiles deployed in the UK has found a similar issue on one in three of the missiles that were checked. More detailed inspections of the missile fleet are under way.
Lab tests show that missiles subjected to a high number of fill/drain cycles are likely to have been damaged by repeated cooling and flexing of the steels used in parts of the engines, oxidiser lines and tank filling points.

The new Selene Board starts to assert its authority, as members know they need to make their presence felt inside the Project and with national governments, or fall into the trap of being ignored. The review of PROM and Explorateur programmes receives the full backing of the Board, with the agreement that flights are to be suspended pending the outcome. A review of Silver Star/Constellation core availability has concluded there will be even fewer cores available than previously thought, meaning a lunar landing appears impossible until well into 1974. This is regarded as unacceptable by all parties (for different reasons) and the 1970 Selene budget should include funds to accelerate core and engine production by BAC and Rolls Royce.

Nov-68 Overseas
NASA's Surveyor 5 touches down in the Ocean of Storms. The lander's thrusters do not shut off properly and it bounces several times before finally coming to rest. It is undamaged and returns nearly 2,000 TV images of the lunar surface, space and the Earth. An experimental arm pushes lunar "soil" around on the surface, demonstrating it has properties similar to fine sand. The lander's electronics survive the two week lunar night and it returns a further 624 image frames during the next lunar day.

NASA also launches SA-303, the third test of its large Saturn III rocket. The test is successful, however one of the three huge F-1 engines shuts down 6 seconds earlier than planned due to a turbine fault. This small deviation from normal is within the performance margin that is available and the vehicle's sophisticated guidance system corrects for the loss in full. It succeeds in putting a modified Apollo Block 2 CSM into an elliptical Earth orbit. 6 hours later, the unmanned CSM accelerates back into the atmosphere to simulate the conditions of a lunar re-entry. The Command Module is recovered in the Pacific.

The Soviet Soyuz 2 mission completes a 4 day flight in low Earth orbit with a crew of three.

Dec-68 Overseas
After discussion with the White House and the new President Elect, NASA decides not to attempt a circumlunar flight with SA-304.
The SA-303 flight still leaves questions over the reliability of the rocket and none of the parties involved want to risk announcing a lunar flight and then not being able to deliver (or worse, trying and failing). Intelligence reports show that the Soviets are still having problems with their "Zond" system, with a failed test flight in October. SA-304 will now be a test launch, before SA-305 puts the "Orbital Lab" space station into Earth orbit in the late spring of 1969.


Dec-68
FA-2 Second test flight of the Black Anvil missile from Rainbow Beach.
Booster performance was normal, however all telemetry ceased at main engine cutoff. Cameras and tracking stations detect RVGC separation and analysis of radar tracking shows that it performing the manoeuvres it was supposed to. The three dummy RVs were separated as planned 18-24 minutes into the flight. The RVGC burned up over northern Canada, 7760mi downrange.

 

[Michel Van]

the "union meeting in Yorkshire incident" is elegant way to keep labor party quite about the Selene project until next election.

 

[sts-200]

the "union meeting in Yorkshire incident" is elegant way to keep labor party quite about the Selene project until next election.

Not just the Labour Party itself - the unions too. It might help to keep the wildcat strikes to a minimum and deflect their attention towards other easier targets ... for a while.

 

[Shevek23]

Well, it's all been a bit disheartening recently hasn't it?

However, the management of the Project has passed its low point. As the saying goes, Rome wasn't built in a day.

That's how I've been looking at it anyway.

 

[Shevek23]

the "union meeting in Yorkshire incident" is elegant way to keep labor party quite about the Selene project until next election.

Not just the Labour Party itself - the unions too. It might help to keep the wildcat strikes to a minimum and deflect their attention towards other easier targets ... for a while.

Hmm. What is the general impression of the British left about cutting edge technical projects such as Concorde OTL or Selene here?

The impression one gets from the policies of Tory versus Labour governments in the 50's and 60s (OTL) is that the Conservatives of that era strongly favored keeping up as much of a cutting edge of British industry as they could, while Labour governments were generally willing to let the Americans dominate by default. Combine that with the conventional wisdom here in the USA that the "left," such as we ever have had one since WWII, is a bit Luddite and scornful of big money being spent on corporate rather than social welfare, and one might guess Labour and the unions, not to mention the far left Communists, would be dead against these projects.

However--it is also my impression that European leftists in general, including British ones, are Futurists as well. They are keen on seeing someone or other develop new technology, and in Britain in particular (as well as France--heck, I think this applies in every European country) would like to see their own nation involved as close to the cutting edge as possible. That they grumble about the distribution of wealth between rich and poor, between the corporations and their workforces, seems proper and after all their jobs--but does this translate into saying "let's not do this wasteful thing" or into "this glorious thing would be money much better spent if only we workers were in charge!"?

My personal guess would be that Labour leaders would mostly agree that stuff like space programs is exactly what a worker's Britain should be doing, if only they could afford it. And here ITTL it seems any doubts they had on that score are being corrected by the sense that the rank and file like it, and accept the expenditure as reasonable-though they might want to stick it to the management!

Do I misread?

 

[sts-200]

Hmm. What is the general impression of the British left about cutting edge technical projects such as Concorde OTL or Selene here?

The impression one gets from the policies of Tory versus Labour governments in the 50's and 60s (OTL) is that the Conservatives of that era strongly favored keeping up as much of a cutting edge of British industry as they could, while Labour governments were generally willing to let the Americans dominate by default.

Yes, as far as it goes, although unlucky timing also had something to do with the Labour attitude. The public finances started to be under much greater pressure in the late 60s. It’s a generalisation, but essentially in the 50s, Britain had no competitors (other than the US), but by the early 60s Europe had been rebuilt and was in a position to compete – and did so very successfully with modern factories, machines etc., which badly managed British industries were too slow to adopt.

Combine that with the conventional wisdom here in the USA that the "left," such as we ever have had one since WWII, is a bit Luddite and scornful of big money being spent on corporate rather than social welfare, and one might guess Labour and the unions, not to mention the far left Communists, would be dead against these projects.

Sort of. Labour has always been a party of two halves – the “union men” (often time-servers, sometimes rather stupid) and “educated social-liberals” (who are often more centrist – I think much closer to US Democrats). Labour doesn't get elected without the centrist types being in charge. Consequently, they have a mixed record when it comes to supporting these sort of programmes. The ‘64-70 govt tried to cancel Concorde twice, and party policy at the time was to aim for state control of production.
Another generalisation: By and large, individual unions didn’t care about anything other than their own narrow field. What they all wanted was “more” for their members, and the Labour party was expected to deliver.
“Real” communists can be discounted – unlike Europe there weren’t many of them in the UK (by then), and certainly none who mattered.

However--it is also my impression that European leftists in general, including British ones, are Futurists as well. They are keen on seeing someone or other develop new technology, and in Britain in particular (as well as France--heck, I think this applies in every European country) would like to see their own nation involved as close to the cutting edge as possible. That they grumble about the distribution of wealth between rich and poor, between the corporations and their workforces, seems proper and after all their jobs--but does this translate into saying "let's not do this wasteful thing" or into "this glorious thing would be money much better spent if only we workers were in charge!"?

Certainly in the UK the brighter members of the Labour party were quite able to push forward with new technology, ideas and economic theory.
[As a side note, one of the best examples died just a few days ago – Denis Healey – as chancellor he was prepared to do what was needed, regardless of politics. Out of necessity, he actually started some of what Mrs Thatcher would massively expand on in the 80s].
Neither the Labour party nor British unions were “internationalist”, on the whole they were fiercely patriotic – indeed later on Labour didn’t even want to join the EEC.

Back on technology programmes, if it was a government project Labour could and did support high tech – e.g. they started the project that would develop the Tornado, kept pouring money into the AGR (nuclear power) programme and agreed to build Black Arrow.

My personal guess would be that Labour leaders would mostly agree that stuff like space programs is exactly what a worker's Britain should be doing, if only they could afford it. And here ITTL it seems any doubts they had on that score are being corrected by the sense that the rank and file like it, and accept the expenditure as reasonable-though they might want to stick it to the management!

Do I misread?

No, spot on.

 

[sts-200]

Forensic Engineering

The Crash of Aurora 2A ​

After the failure of the rocket on Aurora 2, the 2A flight was inserted into the programme to replace it as the first complete test of the capabilities of the PROM.
The ship is successfully launched into a 185x229km orbit. After two orbits, thrusters are used to raise this to 219x229km. A small propane flame inside a "space age Davey lamp" produces heat, moisture and CO2 which closely mimic the respiration of a crew and the cabin conditions are monitored throughout the flight. TV images are relayed from a camera pointing through one of the portholes when the spacecraft is in range of a ground station in France. The ship’s systems are extensively tested, including uplink and downlink from the PROM’s computer and a series of thruster burns. Everything operates normally throughout the 24 hour flight.

Deorbit is at T+23:31 using a solid fuelled retrorocket mounted in the PM. Explosive bolts blow and separate the RM a few minutes later as the spacecraft falls past 150km altitude . After the blazing descent through the upper atmosphere, a recovery ship in the Coral Sea spots the capsule as it falls towards the sea. It quickly becomes apparent that something is badly wrong. Observers see the capsule at about 6,000' trailing a single flapping "streamer". None of the three parachutes are deployed. The RM continues to plummet towards the sea, finally hitting it at over 100mph.

Investigators gather all available telemetry from Aurora 2A as the first step towards finding out what went wrong in the last few minutes of flight. Other than some floating debris, there is no possibility of recovering any part of the capsule, which sank in over 10,000' of water.

Film taken from the recovery ship shows that two of three drogue chutes were deployed, and shortly before impact one of these succeeded in pulling its larger main chute out from the canister (something it should have done at about 12,000'). This main chute did not inflate but remained in its packed configuration, a tightly compressed cylinder, with a few flapping edges visible. Orbital telemetry does not suggest any likely causes and no data was received after re-entry; all of it was recorded onto tapes which sank with the capsule. Capsule drop tests performed from high flying aircraft both before and since the crash have been successful - all 3 parachutes function as designed under the same flight conditions as the Aurora 2A capsule experienced. The chutes also worked perfectly on Aurora 1.

In the absence of any positive evidence, investigators focus on four key questions:
- Why were only two of the three drogues deployed?
- Why did the two drogues fail to deploy their main parachutes as planned?
- Why was one of the main parachutes later pulled out of its container?
- Why did it not then start to inflate?

Having worked flat out for nearly two months, the Aurora 2A investigation team break for Christmas.
While at home on holiday Arthur Miles, an engineer on the team, starts to think about whether there is one common cause to answer all of the four main questions the team is investigating, as opposed to the two or three related causes that are currently under consideration. It is clear that something prevented the parachutes from being deployed; but could this same thing also be responsible for the failure of the drogues and the late deployment of one chute - i.e. a problem that affected the entire system (to varying degrees), but then started to go away by the time the capsule neared the surface. He returns to thinking about a rejected theory - ice. Tests had established that the capsule was not cold enough for ice to form while in the stratosphere, but he thought; What if it formed in space?
At the temperatures found on the outside of an orbiting PROM, ice would rapidly sublime away into space, but maybe there was a cold trap somewhere. Vapour leaking from the ship might then build up, or replenish the ice that was being lost. The parachute canisters are not sealed, so vapour could have got inside.

After the holiday, he sets up an experiment in a vacuum chamber at the National Physical Laboratory. A loaded PROM parachute canister has water vapour vented into it while at very low pressure and at the -30C surface temperature that would normally be encountered on the outside of an orbiting PROM. Within minutes, the canister is visibly laden with ice crystals, however when the vapour supply is stopped, they quickly sublime away. The experiment is repeated, but pulling on the drogue line shows that the nylon parachute material is still perfectly flexible and would be free to be pulled out by the drogue. Still almost full of the parachute, the large aluminium canister is removed from the chamber and the ice theory appears to be disproved.
As luck would have it, a few minutes later, a curious lab technician tries pulling on the chute to see how easily it comes out. It creaks with frost and barely moves; the densely packed layers of nylon now appear to be frozen into a near-solid block. The test is repeated on another parachute canister with much the same result. When the canister is taken out of the chamber and left upside down, the solid block of the frozen parachute falls out after a few minutes, looking very similar to the film of the one main chute that came out of its canister on Aurora 2A.

Now with a solid lead from the experiment at the NPL, the rest of the 2A investigation team look at possible sources for the water vapour. There are only two; an auxiliary cooling vent on the RM, which is used just before re-entry, and a much larger source; the closed cycle generator. This burns Methane and Oxygen, creating steam and other gases which are ducted through radiator pipes used to keep the heatshield and PM systems warm. It is then exhausted overboard, right next to the wall of the RM; the ducts even vent it directly forward and aft, where some of the vapour undoubtedly comes into contact with the front of the RM, right where the "ice cold" parachute canisters are located. Orbital cycles of cooling and heating might allow moisture to migrate into the compressed fabric where it could be retained, even in space. The surface layers might be melted by the warmth of re-entry, but would then freeze again under the influence of the still-cold body of the chute. The ice layer formed by this process could be very effective in jamming or bonding the fabric to the walls of the canister.

Before any complex and costly changes to the design of the spacecraft can be made, this complete theory and possible ways of fixing it must be properly tested. Although it seems likely that the cause of the failure has been found, there is one parameter that could not be duplicated at NPL – zero gravity. This represents a problem; how do you duplicate a cold, zero-G, vacuum environment without going into space?
Engineers at Hatfield come up with an answer; the idea of building a model of the front of a PROM, putting it in a small refrigerated vacuum chamber and spraying low pressure steam over it. The chamber is to be carried inside the "Vomit Comit" (a converted airliner now used to train astronauts in zero gravity conditions), and the experiment is performed while flying a series of “weightless” loops. This bizarre setup should come close to simulating the conditions experienced by the PROM’s parachute containers at the time the problem occurred.

Some argue this test is unnecessary, as vapour diffusion within the nylon fabric is unlikely to be much affected by zero-G; however the Selene Board and the investigation team want to be seen to be acting cautiously. After a good deal of fiddling to make the experiment fit inside the cramped fuselage of an airliner, the tests are complete successfully. There is clear evidence of ice forming inside the parachute canisters even in zero-G near-vacuum conditions. The ice/vapour is retained in the tightly packed nylon layers, partially melting and then refreezing during simulated re-entry conditions.
Test engineers model changes to the direction of the generator exhaust, which produces some improvement, however a safer and simpler solution is to heat the parachute and its canister. This completely solves the issue by preventing ice from ever forming.

The change is in fact very easy to implement; a simple set of parallel-redundant electrical heaters are installed around the parachute canisters. Less than two weeks after the completion of the tests, HSD have completed the modifications to the next PROM. Launch preparations for Aurora 3 can now begin in earnest.

If all goes well, Selene will launch its first astronauts on Aurora 4.

 

[CrazyGeorge]

Always a lovely read, thank you

 

[sts-200]

Falling Short

Dec-68
Problems with the Constellation Stage Adaptor continue on the test rig at Cardington. Versions tested so far are either too stiff, leading to resonance effects in the side boosters, or too flexible, meaning that the booster stages are not held together with sufficient rigidity to prevent their thin walls from being overstressed by control and engine forces.

Dec-68 Overseas
The prototype Boeing 7227 supersonic airliner makes its first flight from Seattle. The project is over a year late and $700M over budget, following changes made in 1965 which formally agreed plans made over the previous year. The design was changed from a swing wing to a delta wing, while also reducing the size of the aircraft. The first flight is a complete success and the 272’ long plane is reported to fly well.

Jan-69 Overseas
The unmanned Soviet spacecraft Zond 6 completes a flight around the Moon and lands safely in Khazakstan. Colour photographs of both the lunar farside and the Earth taken from far out in space are later published, along with the announcement that two mice, Mischa and Anatolya, have become the first mammals to make a journey into deep space.


Jan-69
Top Secret inspections of Blue Streak missiles are complete.
Of 39 operational missiles surveyed, 11 are regarded as unserviceable, with a further 5 described as "marginal". 14 of these 16 are missiles with the highest number of cryogenic fuelling cycles. 6 reserve missiles are all in good condition. This constitutes the entire Blue Streak stockpile. The decision some years ago to cut costs by halting production means that there are no other spares.

British Intelligence is aware of the launch of a large new Soviet rocket from Baikonur. The test is known to have failed and the rocket crashed about 40 miles from the launch pad. It is correctly identified as the first of the new "N-1" lunar rockets. The development programme is known to be suffering delays due to disputes between design bureau chiefs following the death of the Soviet "Chief Designer" Sergei Korolev in early 1968.

Jan-69 Overseas
NASA’s Surveyor 6 lands near the crater Alphonsus. It sends back over 5,000 TV frames of the lunar surface, including the motion of a robotic arm which digs two trenches and grades the surface in order to establish the mechanical properties of the lunar soil.


Feb-69
Emergency plans are developed to refurbish the damaged Blue Streak missiles, followed by a further series of test flights once repairs are complete. The reserve missiles will be brought into service as soon as possible. A squadron of Vulcan bombers, each now armed with two British derivatives of the US B-61 bomb (the first American designed nuclear weapon to enter British service) are to be reassigned back to the strategic deterrent role until further notice.
Longer term, the MoD is instructed to bring Black Anvil into service as soon as is practical, even if this means accelerated deployment of an “interim” version at the cost of slowing development elsewhere. An assessment of the likely availability dates is requested as a matter of urgency.

Nord Aviation and HSD, the firms building the VDL and the PROM, form a joint Change Control Board (CCB) under the supervision of the Selene Board. Amongst the changes recommended by the new Board is the requirement for British and French firms to co-operate much more closely. Until now, the PROM and VDL have been regarded as almost completely separate vehicles, when in fact the VDL-C (the lunar landing version) will need to be a highly integrated craft, with myriad electrical and data connections between it and the PROM.
The effects of design changes on mass, electrical power, cooling systems, communications and crew safety must be carefully monitored to ensure changes to one spacecraft do not adversely affect the other. The CCB will also coordinate between the firms to ensure that their systems are compatible (e.g. French built landing radar must be able to "talk" to British built flight control systems).


Lunar Orbiter A8 / BSLV-19
Last of Selene’s lunar photography satellites. The Lunar Orbiter programme has been dogged by minor failures, resulting in few of the missions being complete successes, although only one was an outright failure (due to the launch vehicle). These minor glitches continue to the end, as the Blue Streak stage of BSLV-19 underperforms and the satellite only reaches a 162x173km Earth orbit. The next burn is made as programmed, leaving the satellite falling short of the Moon. A course correction is made at T+8:26 and the trajectory is further refined at T+61:35. LOI is at T+94:33 and the spacecraft reaches a 137x527km orbit at 78 degrees inclination, lowered to 131x141km on the 3rd orbit.
Over the next 13 days, 457 frames are exposed. Image return begins after the (seemingly inevitable*) film jam. Only 189 pictures are radioed back to Earth before the scanning mechanism fails, however these include good coverage of areas near the poles and several side looking images which can be combined with other photos to create a 3D effect.
The spacecraft's orbit proves to be much more stable than on some earlier missions. Attitude control is lost in December 1969, but the radio transponder is still operational. The spacecraft is tracked until the 14th June 1970 when it hits the lunar surface.
*[it is now known that one of the film coatings that was used degrades slowly in space and would have formed a sticky residue, which could have clogged the film feed rollers, jamming the entire system.]


Feb-69 Overseas
The Soyuz 3 and 4 missions dock in Earth orbit. One of three cosmonauts transfers himself between the two craft while they are docked, riding into orbit on Soyuz 3 and returning to Earth on Soyuz 4. The missions launch and land a day apart, both completing 4 day flights.


Mar-69
Hermes 2 / SSLV-8
Second operational Hermes TV relay satellite for the UK. Successfully injected into geostationary orbit by the Silver Star launcher. The best behaved of all the Hermes class satellites, it suffers no failures during its operational life. By December 1974 its fuel supply is nearly depleted and it is commanded to boost itself into a slightly higher "disposal" orbit. Final direct TV relay is on 12 Feb 1975 after which the satellite is used as a backup transatlantic relay. In August, the fuel tanks are estimated to be empty; there is probably a few pounds remaining in lines and sumps – although no-one can be sure. The satellite is switched off on 2 September 1975.


HSD conclude an agreement for the sales of two Hermes-class satellites to the Canadian Broadcasting Service. Unlike British and Australian versions, these will not be equipped for direct broadcast to the viewer's home. They will instead broadcast the signals to small ground stations for redistribution by cable or conventional radio. Each satellite is also to be equipped to relay up to four radio stations to ground repeaters and to carry up to 150 telephone calls, with antennas for these aimed north to assist in communication with remote Arctic areas.


Mar-69 Overseas
President Nixon forms a committee to formulate options for the future of NASA and the US space program. The "Space Task Group" will report in the autumn with recommendations on the goals and technologies that should be pursued by the US over the next decade.


Mar-69
The Constellation Launch Vehicle management team completes an interim review of the booster design. The first stage design is still in flux, as studies into the concept of reusing the outboard boosters are still underway. However, the performance of the Silver Star rockets on which it is based is now well know and engineers are confident that a flightworthy configuration can be available by the end of 1971.
The ECPS (upper stage) structural design is complete and Sud Aviation are making good progress with a second test article. Efforts to resolve welding issues with the huge, lightweight liquid Hydrogen tanks are in hand and are showing good results so far. Sud are confident that they can deliver the first pre-production stage by March 1970 for integration testing with a mock-up Constellation rocket.
The status of the SNECMA R-1450 main engine is not so encouraging. Early issues with combustion stability and Hydrogen leaks have been resolved, however the engines now on the test stand are overweight and their performance is worse than hoped. These experimental versions are delivering a vacuum equivalent of 423s and 135tf on the test stand, versus the 440s and 140tf called for in the original specification. Much of this shortfall is due to the power-hungry LH2 pump being less efficient than hoped for. To get the engine this far, the pump is being run using off-nominal conditions which also affects the performance of the turbine that powers it (again, reducing its efficiency). Some margin was allowed in the original design specifications and it has been accepted for some time that an efficiency of 435s is likely to be the best that can be achieved.
SNECMA are already working on an improved pump design and a refined nozzle profile, which should raise efficiency to about 433s.
However, there is still a problem; the current CLV design (a “non-recoverable” baseline design from late 1968, with the 433s SNECMA engine) would only be capable of launching a 27.5t payload towards the Moon. The PROM/VDL combination requires a minimum of 28.5t.


Explorateur 4 / SSLV-9
Modified Explorateur spacecraft, with improvements to the basic analogue control systems. Data is received from the soil resistance test and a radiation detector. Contact is lost 38 hours after touchdown. Telemetry suggests that the probe overheated in as the sun slowly rose over the lunar surface.

 

[Shevek23]

...a much larger source; the closed cycle generator. This burns Methane and Oxygen, creating steam and other gases which are ducted through radiator pipes used to keep the heatshield and PM systems warm. It is then exhausted overboard, right next to the wall of the RM; the ducts even vent it directly forward and aft, where some of the vapour undoubtedly comes into contact with the front of the RM, right where the "ice cold" parachute canisters are located. ...

I've been wondering about the generator and its cooling system for quite a few weeks now.

If we were to burn methane and oxygen stoichiometrically, we would introduce three molecules--two oxygen, one methane--and get three molecules--two water, one CO2--plus heat. It was mentioned way up there when the generator was designed to replace the problematic fuel cells that the engine would intake a portion of its cooled exhaust as well as the fuel and oxidant. Presumably this is because the IC engines we use on Earth burn their fuel in air, which has four nitrogen molecules diluting each oxygen; a chamber in which pure reactants combust stoichiometrically would presumably get 5 times hotter than such a mix using Terran air. In theory an engine using such a highly charged mix would be more efficient, but in practice I suppose it would melt (seizing up and breaking first though); the reactants must burn somewhat diluted even if we are using "space-age" very expensive new alloys. I can only guess just how diluted; it is probably possible to improve on the 4:1 ratio of neutral gas to oxygen we get free from our atmosphere, running a bit hotter, but if we could run 5 times hotter we wouldn't be recycling any exhaust at all. Let me just guess we want 3:1.

Stoichiometrically, if the reactions went forward perfectly to ideal equilibrium, we'd have 2:1 ratio of water to carbon dioxide coming out the exhaust. As you mention, the engine actually produces a wider spectrum of outputs, due to reactions never going perfectly like that--presumably there is some carbon monoxide, some hydroxyls, maybe some soot (ie, pure carbon) and some perverse free oxygen. We really want to avoid producing any soot I think so we probably want it to run a bit oxygen rich. So, very little or one hopes practically no soot, vanishingly small traces of monoxide--the contamination would then mostly be leftover oxygen and very small traces of more exotic stuff. No nitrogen compounds since there is no nitrogen! Water, just under half as many carbon dioxide molecules, significant oxygen, and tiny traces of other stuff.

Now even though we're rid of soot, reusing an exhaust that is nearly 2/3 water strikes me as problematic. The water vapor is going to be supersaturated, if not quite coming out the exhaust manifold then certainly when we cool it. It did not occur to me that the PROM complex itself might contain enough heat sinks to cool the stuff down to an acceptable intake temperature in its own structure and I was wondering about radiators. But even then it occurred to me that even if the steam/dioxide mix was acceptable as a diluting medium for the next cycle of reactions, cooling it in radiators would be troublesome. It does not help much that instead of radiators we are running the exhaust to heat the heatshield and strategic points in the PM. Either way we will have liquid water condensing and forming droplets and globs that will render the flow very "slurpy." Nor can i see the engine running smoothly if it intakes a saturated mix of hot CO2 and steam with droplets in it.

It seemed to me therefore that we have to strip out some or perhaps ideally all of the water, and dilute the engine mainly with carbon dioxide. (Some water is OK I guess, governed by what remains vapor at the coolest part of the cycle, presumably just before intake). If we can separate the water from the rest of the exhaust, or anyway most of it, it will presumably still be quite hot when it condenses. And we can pipe that hot water, instead of a mixed gaseous exhaust flow, to keep the PM warm and then take the cooled water and perhaps use it for other purposes.

I've had some notions I've sketched out in my head how to do this. One major concern is that if we propose to use water sequestered from engine exhaust for human consumption in the RM, we need to get as much carbon dioxide out of it as possible as we don't want to multiply the burden on the atmospheric scrubbers. Cool water can absorb quite a lot of CO2.

I don't think we'd need to worry too much about the trace gases produced as they would tend, over time, to slowly react toward equilibrium--especially if we do run oxygen rich.

The point is, nearly half the mass of what we burn in the engine will come out as water; even if our processes waste quite a bit of it we are still accumulating it fast. The engine is less efficient at generating pure water than a fuel cell would be, but then again it is also less efficient at generating electric power too, so we need to consume more reactants to deliver the same wattage, which is to say the amount of water produced ought to be quite similar.

I have this notion of the exhaust, which would be approximately two water molecules to four CO2 plus traces of other gases, coming hot out of the engine and running through a hollow-bladed fan that agitates a bath of hot water to run centrifugally around the rim of a disk, with the exhaust gases first being cooled as they run outward in the blades--a lot of water would condense right there and be blown out, hot, into the water plenum. The gases would bubble out and "up" the centrifugal gradient to be at the hub level, where they are vented out. Hot liquids have low saturation levels for gases so most of the carbon dioxide would bubble out along with oxygenand other gases. This mix would include a lot of the water molecules because the vapor pressure of the water would be high. It might still be more water vapor than we want to intake into the engine, and also the mix might still be too hot, so I envision a secondary cooling/condensation chamber kept at the desired intake temperature by a jacket of cooled water, also spinning--this second chamber would accumulate condensed water. This condensate would be saturated with carbon dioxide, so we would keep it separate from the cooling water outside, and siphon it back to the hot primary separation chamber, where it would help cool that chamber and have its gases cooked out again. The gases that leave the secondary cooling chamber would either be drawn back into the engine as the neutral buffering gas, or a portion will be continually vented to space, to remove the CO2 as fast as it is produced, along with some water vapor that is sacrificed.

The primary condensation chamber would accumulate heat mostly in the form of hot water, so we drain it continually, the hot water being what we use to keep the PM elements warm. In the process the water would be cooled, giving us a stock of cold water which we can also inject into the primary condensation chamber, and jacket the secondary one, and ultimately we must either vent this water into space or else purify it for human consumption.
-----
Now it seems obvious that this rather elaborate scheme of mine would cost some power to run, and has not been adopted on the PROM. But then I have to ask, how does the apparently simpler system you envision keep the exhaust gases used as gases to heat the PM avoid the issue of randomly condensing steam that would I believe gum up the circulation? And would not the cooled exhaust intake be rendered unpredictable by water vapor continuing to condense at all stages until compression anyway? Is it not desirable, and indeed to an extent necessary, to take some steps to separate out some of the water before intake anyhow, even if we decide we don't need or want to conserve the water for secondary uses?

As I understand it, the human metabolism produces more water vapor than we consume as liquid water, just as the methane-burning power generator does. The atmospheric purifying system therefore ought, along with scrubbing out carbon dioxide, also be removing water vapor. I wonder how this was done on Apollo and other OTL spacecraft and if anyone has ever considered a perpetual hydration system that takes drinking water not from urine but from from the air?

 

[sts-200]

I've been wondering about the generator and its cooling system for quite a few weeks now.

If we were to burn methane and oxygen stoichiometrically, we would introduce three molecules--two oxygen, one methane--and get three molecules--two water, one CO2--plus heat. It was mentioned way up there when the generator was designed to replace the problematic fuel cells that the engine would intake a portion of its cooled exhaust as well as the fuel and oxidant. Presumably this is because the IC engines we use on Earth burn their fuel in air, which has four nitrogen molecules diluting each oxygen; a chamber in which pure reactants combust stoichiometrically would presumably get 5 times hotter than such a mix using Terran air. In theory an engine using such a highly charged mix would be more efficient, but in practice I suppose it would melt (seizing up and breaking first though); the reactants must burn somewhat diluted even if we are using "space-age" very expensive new alloys. I can only guess just how diluted; it is probably possible to improve on the 4:1 ratio of neutral gas to oxygen we get free from our atmosphere, running a bit hotter, but if we could run 5 times hotter we wouldn't be recycling any exhaust at all. Let me just guess we want 3:1.

-I actually modelled 4:1 (“dilutant” to “fresh fuel”), however it isn’t nice cool air we are taking in. After leaving the engine’s cylinder, about 20% of the exhaust is dumped overboard, with the remaining 80% going through a radiator, then an intercooler to pre-warm the incoming Methane and O2 stream. Now cooled to about 500K, it is drawn back into the engine’s cylinder, compressed and then the charge is injected (its a modified Diesel cycle, not an Otto/Petrol engine).
Gas temperature will peak at ~2000K immediately after combustion, EGT is just over 1000K, fairly reasonable for any ordinary IC engine design. Overall it’s a very efficient design, about 38% Fuel>Electrical energy – the heat recovery helps.
The gas stays this hot because low temperature radiators are something to avoid where possible in space. Unlike on the ground, they really are radiative; most “radiators” on Earth actually function as convectors.

Stoichiometrically, if the reactions went forward perfectly to ideal equilibrium, we'd have 2:1 ratio of water to carbon dioxide coming out the exhaust. As you mention, the engine actually produces a wider spectrum of outputs, due to reactions never going perfectly like that--presumably there is some carbon monoxide, some hydroxyls, maybe some soot (ie, pure carbon) and some perverse free oxygen. We really want to avoid producing any soot I think so we probably want it to run a bit oxygen rich. So, very little or one hopes practically no soot, vanishingly small traces of monoxide--the contamination would then mostly be leftover oxygen and very small traces of more exotic stuff. No nitrogen compounds since there is no nitrogen! Water, just under half as many carbon dioxide molecules, significant oxygen, and tiny traces of other stuff.

-That’s one of the nice things about Methane, it can be made to burn relatively soot-free quite easily (unlike gasoline, RP-1 etc… which are a horrible mix of compounds). One happy consequence of this is that the generator can run at an O/F ratio of 3:1 – i.e. quite rich – without producing any significant soot.
This is done for one good and one incidental reason:
1) The PROM’s main rocket engine burns at 3:1 (rockets are usually most efficient when run fuel-rich), so the propellant tanks are sized accordingly. Although the difference would be small, its nice not to create an imbalance by running the generator.
2) The energy density at 3:1 is actually better than at 4:1. You “save” a heavy Oxygen atom by creating CO not CO2. The energy you loose by not burning the carbon completely is more than compensated for by the reduction in oxidiser mass.
Of course it isn’t quite that simple – you actually get a whole mix of combustion gases no matter what you do and the heat capacity also comes into it – but the underlying point is sound. Have a look at the attached file for more detail. Its not a perfect simulation, the program was designed for rocket engine modelling. Top run is at O/F of 3:1, bottom one at 4:1. Look at the “chamber” column – 3:1 has slightly lower temperature, but much higher heat capacity due to the gasses being richer in steam and H2.
View attachment OUTPUT.Txt

This is only relevant in space when carrying both fuel and oxidiser. On Earth, with unlimited free Oxygen, we want to burn the fuel as completely as possible to extract the maximum amount of energy. (2) would also be a problem on the ground - you don’t want to vent too much CO – but in space, who cares?

Now even though we're rid of soot, reusing an exhaust that is nearly 2/3 water strikes me as problematic. The water vapor is going to be supersaturated, if not quite coming out the exhaust manifold then certainly when we cool it. It did not occur to me that the PROM complex itself might contain enough heat sinks to cool the stuff down to an acceptable intake temperature in its own structure and I was wondering about radiators. But even then it occurred to me that even if the steam/dioxide mix was acceptable as a diluting medium for the next cycle of reactions, cooling it in radiators would be troublesome. It does not help much that instead of radiators we are running the exhaust to heat the heatshield and strategic points in the PM. Either way we will have liquid water condensing and forming droplets and globs that will render the flow very "slurpy." Nor can i see the engine running smoothly if it intakes a saturated mix of hot CO2 and steam with droplets in it.

-Primary heat rejection is through radiators (its just that some of the leftover heat is used to keep a few parts a bit warmer). With a cylinder exhaust gas temp of about 1000K, they will just about glow dull red at the input.
At a radiator exit temperature of about 500K at low pressure, there is no liquid water at any stage.

It seemed to me therefore that we have to strip out some or perhaps ideally all of the water, and dilute the engine mainly with carbon dioxide. (Some water is OK I guess, governed by what remains vapor at the coolest part of the cycle, presumably just before intake). If we can separate the water from the rest of the exhaust, or anyway most of it, it will presumably still be quite hot when it condenses. And we can pipe that hot water, instead of a mixed gaseous exhaust flow, to keep the PM warm and then take the cooled water and perhaps use it for other purposes.

I've had some notions I've sketched out in my head how to do this. One major concern is that if we propose to use water sequestered from engine exhaust for human consumption in the RM, we need to get as much carbon dioxide out of it as possible as we don't want to multiply the burden on the atmospheric scrubbers. Cool water can absorb quite a lot of CO2.

-That’s the big disadvantage of this system – unlike a fuel cell, they can’t recover the water. However, they don’t need a heavy supercritical H2 tank and the generators themselves are lighter than fuel cells, helping to offset the extra mass of fuel and drinking water.

I don't think we'd need to worry too much about the trace gases produced as they would tend, over time, to slowly react toward equilibrium--especially if we do run oxygen rich.

-If you are introducing water into the cabin environment it needs to be fairly clean, so there would need to be some sort of filter/molecular sieve built in. As a minimum you would want to take almost all the CO, CO2 and any hydrocarbons out of it. It’s all doable, but all those filters and separators would be yet more mass.

The point is, nearly half the mass of what we burn in the engine will come out as water; even if our processes waste quite a bit of it we are still accumulating it fast. The engine is less efficient at generating pure water than a fuel cell would be, but then again it is also less efficient at generating electric power too, so we need to consume more reactants to deliver the same wattage, which is to say the amount of water produced ought to be quite similar.

I have this notion of the exhaust, which would be approximately two water molecules to four CO2 plus traces of other gases, coming hot out of the engine and running through a hollow-bladed fan that agitates a bath of hot water to run centrifugally around the rim of a disk, with the exhaust gases first being cooled as they run outward in the blades--a lot of water would condense right there and be blown out, hot, into the water plenum. The gases would bubble out and "up" the centrifugal gradient to be at the hub level, where they are vented out. Hot liquids have low saturation levels for gases so most of the carbon dioxide would bubble out along with oxygenand other gases. This mix would include a lot of the water molecules because the vapor pressure of the water would be high. It might still be more water vapor than we want to intake into the engine, and also the mix might still be too hot, so I envision a secondary cooling/condensation chamber kept at the desired intake temperature by a jacket of cooled water, also spinning--this second chamber would accumulate condensed water. This condensate would be saturated with carbon dioxide, so we would keep it separate from the cooling water outside, and siphon it back to the hot primary separation chamber, where it would help cool that chamber and have its gases cooked out again. The gases that leave the secondary cooling chamber would either be drawn back into the engine as the neutral buffering gas, or a portion will be continually vented to space, to remove the CO2 as fast as it is produced, along with some water vapor that is sacrificed.

The primary condensation chamber would accumulate heat mostly in the form of hot water, so we drain it continually, the hot water being what we use to keep the PM elements warm. In the process the water would be cooled, giving us a stock of cold water which we can also inject into the primary condensation chamber, and jacket the secondary one, and ultimately we must either vent this water into space or else purify it for human consumption.

-Centrifugal separation is one valid way of doing it (the other obvious one being fractioning via adsorbtion to temperature-controlled plates at known pressure). However, all those mechanical systems are going to quite heavy and the low-temperature radiators needed to condense the water in the first place would make it even heavier. On a longer duration mission it might be worth it, but for a few weeks on the PROM, its easier just to dump the lot.
If they wanted to be clever, they could use the generator exhaust as a low-impulse RCS system; but the PROM doesn’t do that either.

Now it seems obvious that this rather elaborate scheme of mine would cost some power to run, and has not been adopted on the PROM. But then I have to ask, how does the apparently simpler system you envision keep the exhaust gases used as gases to heat the PM avoid the issue of randomly condensing steam that would I believe gum up the circulation? And would not the cooled exhaust intake be rendered unpredictable by water vapor continuing to condense at all stages until compression anyway? Is it not desirable, and indeed to an extent necessary, to take some steps to separate out some of the water before intake anyhow, even if we decide we don't need or want to conserve the water for secondary uses?

-In the exhaust duct (I mean the vent out to space, not from the engine cylinder) the pressure would be so low that there cannot be any liquid water. Vapour or ice only, and the temperatures would be far too high for ice. During startup and shutdown sequences there might be some short-lived condensation inside the system (like a car exhaust on a cold day).

As I understand it, the human metabolism produces more water vapor than we consume as liquid water, just as the methane-burning power generator does. The atmospheric purifying system therefore ought, along with scrubbing out carbon dioxide, also be removing water vapor. I wonder how this was done on Apollo and other OTL spacecraft and if anyone has ever considered a perpetual hydration system that takes drinking water not from urine but from from the air?

On Apollo (and everything else to the best of my knowledge) it was done using an adsorbtion cold plate and a wick to draw the moisture away in zero-G. It’s one form of the fractioning I mentioned above and much the same process as an air conditioner/dehumidifier. Apollo and the Shuttle dumped the condensate overboard along with other surplus fluids.
The ISS recycles cabin moisture and urine. Skylab didn’t, it just had big water tanks and a limited life.

 

[Dathi THorfinnsson]

Dec-68 Overseas
The prototype Boeing 7227 supersonic airliner makes its first flight from Seattle. The project is over a year late and $700M over budget, following changes made in 1965 which formally agreed plans made over the previous year. The design was changed from a swing wing to a delta wing, while also reducing the size of the aircraft. The first flight is a complete success and the 272’ long plane is reported to fly well.

7227 seems an odd designation for a Boeing SST. Why that?

OTL, of course, it was 2707 for the Mach 2.7 flight speed and '7x7' naming system.

Interesting butterflies that it actually makes it into the air. OTL, Boeing execs (later, in hindsight) were very glad they never built the plane as they would have gone under due to development costs (of that and the 747, which would have been roughly the same time). Are we going to see Boeing collapse here? Maybe be taken over by one of the other primes?

The status of the SNECMA R-1450 main engine is not so encouraging. Early issues with combustion stability and Hydrogen leaks have been resolved, however the engines now on the test stand are overweight and their performance is worse than hoped. These experimental versions are delivering a vacuum equivalent of 423s and 135tf on the test stand, versus the 440s and 140tf called for in the original specification. Much of this shortfall is due to the power-hungry LH2 pump being less efficient than hoped for. To get the engine this far, the pump is being run using off-nominal conditions which also affects the performance of the turbine that powers it (again, reducing its efficiency). Some margin was allowed in the original design specifications and it has been accepted for some time that an efficiency of 435s is likely to be the best that can be achieved.
SNECMA are already working on an improved pump design and a refined nozzle profile, which should raise efficiency to about 433s.

1) what is 'tf'? Presumably ton/tonne force. If so, which ton? Long, short, or metric? I don't think I've ever seen engine specs in 'ton force' before.

2) This section on Isp is confusing. It sounds like 435 is the best they can do now, and SMECMA is trying to raise it to 433. (raise from 5 to 3...)
I suspect you meant they were trying to raise it to just short of the max they could hope to get in the near term. 433 is very close to 435, what changes can't they do now, that they expect to do over the years that would give them 2 more seconds?

Or is there a typo here somewhere?

 

[sts-200]

7227 seems an odd designation for a Boeing SST. Why that?

OTL, of course, it was 2707 for the Mach 2.7 flight speed and '7x7' naming system.

Interesting butterflies that it actually makes it into the air. OTL, Boeing execs (later, in hindsight) were very glad they never built the plane as they would have gone under due to development costs (of that and the 747, which would have been roughly the same time). Are we going to see Boeing collapse here? Maybe be taken over by one of the other primes?


1) what is 'tf'? Presumably ton/tonne force. If so, which ton? Long, short, or metric? I don't think I've ever seen engine specs in 'ton force' before.

2) This section on Isp is confusing. It sounds like 435 is the best they can do now, and SMECMA is trying to raise it to 433. (raise from 5 to 3...)
I suspect you meant they were trying to raise it to just short of the max they could hope to get in the near term. 433 is very close to 435, what changes can't they do now, that they expect to do over the years that would give them 2 more seconds?

Or is there a typo here somewhere?

The 7227 of the story isn’t the same as the 2707 (hence the different name – much like the story’s “Saturn 1A”). The US SST started earlier in the story. It’s a bit smaller, lighter and slower and they abandoned the swing-wing concept early on. The “22” is a reference to the top speed – intended to be Mach 2.2.
It’s closer to the plane the Americans should have tried to build (rather than the over-ambitious 2707) and/or the plane Britain and France should have built (rather than the too-small Concorde).

It’s an Anglo-French project, engineers are taking great care to ensure everything is metric … except for the bits that aren’t.

It certainly requires careful reading. Summary:
Original paper spec – 140tf, Isp of 440s.
Experimental version currently on the testbed is delivering 135tf & 423s.

Designers have known for some time that 440s isn’t going to be achieved - 435s is probably as good as it gets.
SNECMA already have plans to improve the current engine to from 423 to 433s. If they want to go higher, they’ll have to do more of what they do best.

 

[sts-200]

The Wrong Stuff

Early Explorateur flights

Explorateur 1 left the pad and was never heard from again. The investigation team’s best guess was that the radio system failed, possibly due to static discharge. The probe hit the Moon 3 days after liftoff.

On Explorateur 2, the radio worked perfectly; the thrusters didn’t. The probe sailed past the Moon and out into interplanetary space where it remains to this day.

Explorateur 3 entered lunar orbit and slowed to a near-perfect stop.
Unfortunately, the point at which it stopped was about a mile above the lunar surface. With thrusters still firing, it started to ascend, ran out of fuel and crashed.

Explorateur 4 completes the first soft landing on the Moon by a Selene spacecraft. Controllers cheered as the data confirmed that the probe had touched down and the engine had shut off. Every system worked perfectly, except the TV cameras.

From the start, Explorateur was to be an all-French programme and in the early years they guarded it jealously. As a consequence, its builders made many of the same mistakes made by British spacecraft engineers a few years earlier, and by the Americans a few years before that. Building a craft to survive the electrical, thermal, magnetic, radiation and vacuum environment of space requires its own special approach.

Plastics that work well on the ground can evaporate in space. Insulators that work reliably in air are terrible in vacuum. Everything from the coatings of electrical components to the adhesives used in seals needs to be carefully selected and tested to withstand the environment. Unfiltered solar radiation, the static electrical discharges caused by rocketing up through the atmosphere or the need for absolute verification of systems that no-one would ever see again all took their toll on every nation’s early attempts at space flight.

Fundamentally the Explorateur probes were a perfectly good, if somewhat odd, design. After separation from its Silver Star launcher, the probe uses a “cruise stage” - four separate RCS modules linked by an electronic control system with its own batteries and radio – to fine-tune its course towards the Moon and communicate with Earth. A solid fuel motor provides a fixed impulse for lunar orbit injection, and after that the cruise stage thrusters are used again to nudge the probe’s orbit closer to the surface. Before the descent begins, the cruise stage falls away. Now under the control of the lander’s completely separate command system, another solid motor is designed to decelerate it to about 100m/s before small liquid fuelled thrusters gently lower it to the surface.

When an Anglo-French investigation team is convened after the loss of Explorateur 1, British engineers see every detail of Explorateur for the first time. Their comments range from constructive criticism to the positively undiplomatic. Explorateur is "definitely not British" in its design philosophy and implementation. It makes extensive use of analogue control circuits and the lander’s control system is not fully transistorised. The separate modules work virtually independently of each other to perform each stage of the flight in sequence. There is little flexibility in the control system. Beyond some basic feedback loops, it cannot correct for off-nominal flight conditions, so automatic sequences are likely to work either perfectly or not at all.
The entire system has been designed and built from (valid) theories, but without the benefit of actual spaceflight experience. In the British view, the level of ground-based testing is inadequate to ensure reliable operation without an extensive test flight programme. Differing views, personal frictions and background British concerns about the politics of the Project in early 1968 mean that the investigation team members do not work well together.

Materials problems show up on Explorateur 2. A command is sent to fire the engines, but nothing happens. This time, engineers from Sud Aviation are able to identify what is happening. The inability to fire the engines on any of the seven modules comes down to one piece of design that is common to all; timing devices that are used to start and run the engines for the commanded time.

French investigators subsequently find that one of the plastics used in the construction of these timing circuits is made of the wrong stuff, the material degrades rapidly when it becomes hot in vacuum. Coatings less than a millimetre thick would have failed very quickly once in space, causing short circuits, affecting oscillators and discharging capacitors almost immediately. Cycles that should take milliseconds would happen in microseconds (or not at all), meaning that the timers can never provide a meaningful signal to the systems they are supposed to control.

Perhaps the only grain of comfort at the time comes from the fact that the Americans also seem to be having difficulties with their “Surveyor” lunar lander programme, the last two of which have also failed.

Having resisted attempts at British interference and in an attempt to keep the Explorateur programme moving, Explorateur 3 is launched after changes have been made to the design of some of the electronics. After a successful launch and cruise out the Moon, timers are set for lunar orbit injection at T+72:52 using the solid rocket motor. A 135x692km orbit is achieved; somewhat higher than planned as the motor seems to have underperformed. The small thrusters are used on the third orbit to cut this to 135x221km, taken down to 23.8km on the fifth orbit.
In the control room in Biscarosse in western France, a hurried conference is held over whether to delay the landing to lower this further - the probe’s design calls for closest approach to be 15-20km before the landing deceleration burn begins. Cruise stage batteries are at just 9.5% of capacity, and another two orbits (4 hours) would see this fall dangerously close to zero. A decision is made to accept the higher orbit and attempt to land at the next opportunity in about 2 hours’ time.
Having done its job, the cruise stage is jettisoned at in preparation for the landing attempt at T+86:37. Telemetry shows the deceleration burn is completed, leaving the lander at 20km altitude, heading towards the surface at nearly 200m/s, far faster than was planned.
Nevertheless, the probe tips up to a vertical orientation and fires its landing thrusters to stabilise itself until the radar altimeter locks on as it passes 7.8km. The system commands the thrusters to ramp up and slow the probe, but no touchdown indication is received before the fuel runs out. Oddly, the altimeter reading starts to increase while the engines are still firing. Landing radar lock is lost again when indicating 8.6km altitude, with the rate of ascent shown as over 400m/s.
All telemetry ceases 118s later. It is clear that the probe has crashed.

Detailed analysis of the telemetry of Explorateur 3's final moments show what happened to the probe. The landing engines fired at too high a thrust setting, bringing it to a complete stop 2km above the lunar surface. With engines still firing, the probe then accelerated away from the surface until it ran out of fuel. Once out of fuel, it was left in a slow spin, which caused the landing radar to start to "look" away from the vertical, showing a rate of ascent far higher than it really was. The probe actually reached a maximum altitude of just under 4km before falling back and crashing.
Later analysis shows that a mis-set bias in the lander's accelerometer system caused the probe to decelerate too quickly when descending towards the Moon. The probe's guidance system acted as if lunar gravity was nearly twice as strong as it really is, meaning that instead of slowing to a hover just above the surface, it stopped 2km above it and then accelerated away again.
Problems with translunar navigation and the braking burn are put down to an unrelated fault in the cruise stage accelerometers and unexpected deviations in the performance of the analogue attitude control system caused by thermal cycles.
Better news is that the probe's horizontal velocity was successfully brought to zero by the automatic landing system, meaning it would have touched down vertically if the other systems had worked.

The review board is split as to what changes should be made before flights are resumed. French engineers who are closely involved in the Explorateur programme are confident that once adjustments are made to the systems, the next probe will make a successful landing. They point out that despite the problems, it completed most of its flight and did successfully decelerate near to the lunar surface. They will fit larger cruise stage batteries to future probes, which will allow ground controllers more time to make decisions and fine-tune the trajectory.
British engineers (and many French ones from the other parts of the industry) regard these “insider attitudes” as dangerously flawed, similar to arguing that an aircraft works just because it successfully flies across the Atlantic, even if it then crashes 1000' short of the runway. Their conclusion is that the Explorateur control system lacks the flexibility and precision to reliably land on the Moon. The "point and shoot" guidance system, augmented by a series of analogue control loops could theoretically achieve a successful touchdown, but only if everything goes to plan and all components perform exactly as designed. They put the chance of a successful landing with the current system at less than 40%.
What is needed is a full guidance system, with an inertial platform, better integrating accelerometers and a modern digital programmer capable of accepting a wider range of triggers and commands than the present system.

One of the first decisions of the new Selene Board is to suspend Explorateur flights. As part of a wider programme of changes, British and French parts of the Project must learn to work closely together. However, there is still politics to be played and to help keep the peace between the various parties, the decision is partly reversed. It is decided that the Explorateur programme will proceed in two phases. Explorateur 4 will be launched once modifications to the existing guidance and control systems are complete. A joint Anglo-French development team (almost a first in the 5 year history of the Selene Project) will design and test an improved guidance and control system, using French built components and industry (in recognition that Explorateur is still a French part of the Project).
It is expected that E-4 will be ready for launch within 3 months, with the first of these “improved Explorateurs” available in the autumn of 1969

After a series of miscalculations and minor faults, which serve to confirm that the programme is still in need of overhaul, Explorateur 4 reaches lunar orbit in March of 1969.
The deceleration burn is completed, leaving the probe at 13.5km altitude, descending at 89m/s. Landing radar locks on at 5,300m and the system starts a controlled descent to a touchdown at T+89:31, only 6.5km from the nominal landing site. The probe still has 65kg of its original 205kg fuel supply remaining when the engines shut off. Controllers at Biscarosse are out of their seats cheering; their revised techniques and more precise pre-launch checks seem to have paid off.

Surface experiments and the TV camera deploy automatically after landing, but celebration turns to disappointment when the first TV images are returned four minutes later. The pictures are completely blank, showing no details of the surface at all. All subsequent images are the same. Having returned a tiny amount of data on the electrical properties of the lunar surface, Explorateur 4 goes quiet 38 hours after landing.

“Less than 40%” had been proven to be about right. Only one of four had landed successfully. However, despite all the publicity surrounding the faults and failures, engineers and managers were learning from their failures and the Project had taken an important step forward.

Even though there were no pictures, Selene had shown that it could reach the Moon.

 

[sts-200]

The Cost of Penny-Pinching

The Ultimate Might-Have-Been; the Reusable Constellation Rocket​

In early 1968, while the debate over the future management of the Project raged, what remained of the SPC conducted some useful studies of the test flight programme with a view to cutting it down in order to save both money and booster cores. Early Selene plans simply assumed that Silver Star rocket cores would be available “in quantity”, however time pressures, budget cuts and the demands of Britain’s deterrent programme mean that the Project could have access to as few as 39 new cores up to the end of 1973. The requirements of Explorateur and Aurora missions means that only 23 of these are available for other flights.

Each of the large Constellation launchers will use three cores, so the committee proposes switching development flights of the Constellation’s Hydrogen fuelled upper stage (the ECPS) to single core vehicles (i.e. fly Constellation but without the two outer cores). These would not carry any other payload but would allow the ECPS to be tested in flight without the cost of a complete 3 core Constellation vehicle. It is recommended that two of these ECPS development flights should be flown, with provision for a third in case further tests are needed.

Once these are completed, two all-up Constellation test flights would then carry complete PROM/VDL-C spacecraft on unmanned tests in high Earth orbit; flights which the SPC informally names Selene missions A and B. Two manned but lightly fuelled versions of the PROM/VDL-C will fly on Silver Star boosters to test the complete lunar lander and its systems in Earth orbit; informally called Aurora 13 and 14.

The remaining 12 cores will be allocated to 4 Constellation rockets. One will launch an unmanned VDL-Cargo mission on a test flight to the lunar surface (Selene C). The next will send a manned PROM/VDL-C into lunar orbit (Selene D), on a mission that will not attempt to land but will test lunar orbit navigation, landing procedures and provide high resolution photography of future landing sites.
The last two Constellations will be used to launch the cargo ship and manned lander for Selene E, the first manned lunar landing attempt by the Selene Project. Later flights will rely on cores delivered after the end of 1973.

The committee is aware that this is a compressed test programme offering little margin for error, so in an attempt to increase flexibility, BAC are asked to investigate the potential for recovering the two outer cores of the Constellation launcher.

With the inevitable delays that occur with the hand over of duties to the newly formed Selene Board, it is not until October 1968 that BAC are able to present a short report on the possibility of recovering these two outboard boosters. They conclude that it is technically feasible, but that the current design for the Constellation Stage Adaptor (a large but lightweight structure which joins the three cores together) would need extensive changes. Wind tunnel tests suggest that re-entry stabilisation could be handled using passive control (i.e. by stabiliser fins or other drag devices), however heat shielding would be needed in several areas and parachutes or touchdown rockets would be required. To increase performance, a pump system to transfer fuel between the outboard boosters and the core could be developed without much difficulty, however it would require additional plumbing on all three cores. The report concludes that the development costs might be recovered over as few as 12-15 launches, assuming each booster can be used 3 times. The Orion rocket engines are proving to be quite rugged; several have completed ground based tests with start/stop cycles and firing times more than double their original design specification – more than adequate for 3 flights.

Reluctant to commit to building a reusable rocket in addition to all the complexity of landing on the Moon, the Selene Board delays and asks BAC and Rolls-Royce whether they could increase core production instead. However, barely three weeks later the Board is notified that there will be no additional funds available to increase the core production rate. Worse, Britain’s MoD now requires additional cores to keep in reserve for the strategic missile force, and two more are being kept back for use on satellite launches that are unrelated to the Selene Project. That leaves only 19 cores available for use once the basic Explorateur and Aurora programmes are completed, an insufficient number to permit a lunar landing before the end of 1973.

Still reluctant to commit and uncertain as to how to proceed, the Board asks BAC to update their study into the recovery of the two outboard boosters and to further assess the time and cost of changing the existing design, which after all, is well into development.

There is good news at a briefing by engineers working on the Stage Adaptor (the CSA). The concept of separating the two outer boosters now seems much easier, following changes to the design of the Adaptor in recent months. To help avoid the vibration and resonance problems encountered on the test stand over the last year, the Adaptor has evolved into a highly rigid structure fixed to the central core, with a system of tuned load beams to take the thrust from the outer cores. The central and outer structures are therefore separate and have to include a series of attachment points to allow assembly. These points could be redesigned to include explosive fasteners which would allow the core and outer boosters to be separated. Stabiliser points at the lower end of the cores were always designed to be flexible and can be modified to include a release mechanism.

To help them verify models of the aerodynamic forces on a returning rocket stage, in April 1969 BAC engineers launch a scale model of a Constellation side booster using a modified Skylark sounding rocket. On the first test, the parachute attached to the model fails to deploy and it crashes, however film of the descent shows that the configuration was unstable at high speed. A second launch a few weeks later carries a different design, equipped with deployable airbrake fins near the engine bay to help stabilise the model in a nose down entry. The test is much more successful; this time, the model is recovered. Subsequent tests and wind tunnel studies confirm that a full size booster equipped with similar fins could remain stable throughout its re-entry.

With the shortage of cores ever more acute (the number likely to be available has fallen to 17 by June 1969), BAC are awarded a contract to implement their recovery system design, along with several other changes. Most important of these is that the recoverable side cores will transfer part of their fuel into the central core during the early stages of the flight. After helping to lift the vehicle off the pad, while transferring sufficient fuel to feed the engines of the central core, the outer two "wing boosters" will be jettisoned at a low speed (a mere 4,000mph or so), leaving the fully fuelled central core to continue carrying the upper stage and payload. There is no longer any need to jettison the outer rings of 6 booster engines on each core, and the explosive couplings for these can be removed. The central core will not be recovered, it will burn up on re-entry around 3,500 miles downrange.



Even with the additional mass of the fuel transfer and recovery systems, and the underperforming R-1450 engine on the ECPS, this new design will result in a huge performance increase for Constellation. The rocket should now be able to propel 32 tons towards the Moon. Despite the fact that there is still a lot of development to do on the booster recovery systems, engineers are now certain that they have a basic design with the performance margins needed to launch a crew to the Moon. A fuel transfer system had been proposed in the early 60s when Constellation was still in the planning stage. In one of life’s little ironies, designers at the time were congratulated for rejecting it as unnecessary, in favour of retaining Silver Star’s simpler and cheaper booster ring jettison system. Now, years later, many of the same team are praised for putting it back into the design. Fuel transfer provides a vital performance boost and will allow SNECMA to move towards production of their R-1450 engine, without the delays that would be incurred by having to make further improvements to the design.

BAC also propose something else … a system that might just have transformed the entire space program. Essentially a simplified version of the earlier MUSTARD concept, two recoverable outer cores would carry a central core coated in heatshield materials and equipped with a basic on-orbit manoeuvring system. If all went to plan, all three cores would survive the plunge back through the atmosphere, creating a completely reusable launch vehicle.
Unlike the more sophisticated NASA Shuttle proposals that would emerge, this vehicle would only be used as a launcher – it would go into space, complete just one orbit and then return, deploying a payload of about 25 tons along the way. BAC estimated that the cost per flight could be low as £1M and pointed out that a more than a dozen US firms had said they would build orbital labs, factories, even hotels if launch costs could be this low. The proposal certainly attracts a lot of attention, but in Britain there is no appetite for spending yet more money on space research. The fact that BAC are simultaneously pressing for government backing of their new “3-11” airliner concept makes funding even less likely.

Late in 1969, the basic Constellation booster recovery programme comes under attack from officials at the MoD, who argue that this “new design variant” will interrupt the production of their vital Black Anvil missiles. The Selene Board states that there is only a shortage of 5 or 6 cores and the MoD claims this could easily be made up by the end of 1973 through an increased production rate, at a known cost of about £5M per core. The MoD are in for a shock as the Treasury defend the reusable booster programme. Estimates provided by BAC put the cost of development at £45M, offset by savings of £32M in operational costs. Overall, this represents a reasonable saving on the £30M production costs for additional cores.
BAC have also engaged in a significant lobbying campaign with both the Chancellor and Minister of Technology in favour of their new programme, sweetening the message with the hint that they are in the early stages of discussions with an American firm regarding other potential uses for the recovery technology.

 

[Shevek23]

The Ultimate Might-Have-Been; the Reusable Constellation Rocket

There is always a certain amount of dry humor in the material you so realistically present, you know. I was bracing myself for a big disappointment but it turns out your title refers to, as it says, the Ultimate reuse scenario, recovering all three cores. Meanwhile a penultimate reuse scenario that is vastly improved over anything that has happened hitherto in OTL now seems practically guaranteed, championed by none other than the same Treasury that seemed determined to do in the whole British space effort only yesterday! And everyone is sad because they only get to recover two out of three!

Until this post, I had never pictured Constellation as being three Silver Star stages in a row with the upper stage mounted on the top. Nope, I pictured them as being in a symmetric triangular cluster of three, with the upper stage stuck between them equally on the centerline of the triangular prism their centers would define. I suppose I'm just silly.

In view of this confusion I can see how you might have found some of my earlier suggestions quite unintelligible.

One of the things I've meant to comment on for months now has been the scheme to drop the outer six of the seven Orion engines, followed by the later plan to try and recover these dropped engines for reuse. (If you ever sketched how the capsules containing pairs of them were supposed to look and work, I'd like to see them!) It was apparent to me what the motive was; the seven engines are identical, yet one of them burns much longer than the other six, implying waste of potential for the majority unless they are used again.

Have you heard much about proposals for Thrust Augmented Nozzles? IIRC it is a concept patented OTL by Aerojet, but not yet to my knowledge employed anywhere. The basic concept is, introducing some sort of additional propellant into the nozzle of a rocket engine. As I've seen it presented the examples speak of combustible mixes.

As I'm sure you're well aware, a nozzle that is designed for optimal performance in a vacuum is at best going to underperform at sea level, and most likely cannot be used at all, because the design that makes the gases expand to the optimum degree in vacuum will fail to do so at sea level; the back pressure of the atmosphere will impede the flow and in particular cause the boundary layer actually flowing along the nozzle inner surface to be forced back up from the rim. This is bad enough, meaning the thrust and thus effective ISP as well of the exhaust is lowered, but worse, that forcing back inside the inner rim is unstable; the fluctuating boundary makes for resonant waves in the nozzle which can destroy it. Therefore engines that are going to be lit on the ground must have shorter nozzles that compromise available thrust.

As this applies to Orion and the Black Anvil/Silver Star, all seven engines are lit on the ground and must therefore have the short nozzles. If all of them shut down at the same time, this is just the way it must be. But the center engine of the cluster is meant to keep burning and operate well into vacuum; it is a pity it must suffer the liability of sea-level optimized nozzles. But what else is to be done?

Some have proposed making variable-geometry nozzles of course, sliding a nozzle extension down to lengthen it once it has risen high enough. This strikes me as clumsy but it has been done. This would moderately augment the thrust at high altitude, but at obvious costs and risks.

The proposal to make Thrust Augmented Nozzles suggests that instead, one can go ahead and design the nozzle for high-altitude operation, but when firing it at sea level, introduce additional gas flow around the rim, to fill in the space that otherwise would be pushed back and unstable with a stable augmented flow. This not only allows for optimum efficiency at altitude, it actually raises the total thrust right when we want it the most, at launch. As the rocket rises into thinner air the augmented flow is throttled back and eventually stopped and the rocket proceeds as a vacuum-optimized version on its main chamber propellant alone. It obviously requires extra propellant and thus the mass flow is raised, while the combustion and expansion is not as efficient and so the thrust is not increased in proportion--which is to say, ISP is lower. (However, in view of sea level ISPs being always significantly lower than vacuum, it may be that the new average, lower than vacuum ISP, is actually also higher than normal sea level ISP!) But it means that as a trade-off for worse mass flow for a given unit of thrust, an engine can raise its thrust briefly beyond its nominal design maximum (a maximum also raised by the more efficient nozzle). Indeed the papers I've read talk about really large multiplications of thrust, factors of 2 or even 4!

However I'm not suggesting that here and now. What I'm suggesting is that the single central Orion engine might do with a redesign for better vacuum performance, if some extra propellant can be injected into the bigger nozzle, not so much with a view to raise the thrust to fantastic levels briefly, but simply to just fill the nozzle with something adequate to prevent the destructive overexpansion.

As I say, the Aerojet briefs talk about injecting more combustable mix, oxidant and propellant both, and burning them. They do point out that the mix need not be identical to what goes through the main chamber; they are thinking of massive augmentation of very large bell nozzles, and thus having a hydrogen engine that starts out augmented with four times its base thrust by means of a ker-lox mix, this in effect makes the engine a tripropellant model.

I wonder though, what if an Orion engine with modestly extended nozzle were to have high test hydrogen peroxide sprayed in downstream from the throat, perhaps near it or perhaps down near the rim, instead? A problematic aspect of burning a mix in the nozzle is that everything is already flowing out very rapidly; there is little time for combustion nor are conditions optimal either for it to go forward or for the resulting heat to be captured with full efficiency. Hence the lower ISP. But hydrogen peroxide molecules, upon hitting the flow of hot main chamber exhaust at any point, will surely decay immediately, releasing at any rate the energy of HTTP monopropellant, which corresponds to an ISP of 120 or so. This is with optimal expansion of course, which is not happening, but at any rate this energy release is certain and instant, so what heat there is is available to be expanded albeit inefficiently. The idea is to coat the lower nozzle with a layer of exhaust that is adequate to keep the air out and stabilize the flow; the layer of decayed peroxide at any rate serves as a virtual nozzle liner, in which the main propellant expands as much as it can flowing into dense air, getting what efficiency out of it is possible, while the solid nozzle stands ready to do a better job in the thinning upper air as the peroxide is throttled back, allowing gradually better expansion of the main flow. The peroxide might not contribute a whole lot of extra thrust but it does add something. Also, the main chamber exhaust is as you've pointed out, fuel rich, while the peroxide releases energetic oxygen atoms. These might possibly burn some or all of the unconsumed fuel, releasing more energy and thus, despite delayed reaction making the expansion of the product less efficient still, at any rate further augment the thrust a bit. And finally, the peroxide, although guaranteed to flash into a hot gas by its instability encountering the main flame, is much cooler than that main chamber exhaust; it insulates the nozzle, delaying any deterioration that heat might cause.

Of course in an expansion cycle engine that is meant to cool that nozzle regeneratively and then use the heat to drive the turbine, that's a mixed blessing at best! It would tend to rob the turbine of some of its power--to be sure the main chamber is still putting out the same standard heat and I guess that is where most of it comes from. And you have a mixed enhanced cycle with a burner assisting the heat a bit; here we could just burn that a little hotter to make up I'd think.

So if the central engine of the cluster were modified in this way, we'd wind up needing to boost a bit more mass, in the form of a reserve of hydrogen peroxide, but we'd have a bit more thrust from the center engine too at launch. And as the rocket climbs to the level where the outer engines are ditched, the thrust of the center engine would fall--but not all the way down to the standard level of an unmodified engine; it would always produce extra thrust, but at altitude at maximum and indeed improved ISP.

It is perfectly clear now to me that the two outer boosters of a Constellation would, under the modified reusability plan, cross-feed to the central booster, thus starving their own tanks of the remnant propellant that was going to feel the seventh engine--all seven of the outers now burning out at the same time. Thus, we would not want any of those 14 Orions to be modified in this fashion; they never rise up high enough to justify the vacuum optimized nozzle.

What is less clear is what happens to the seven engines of the central booster driving the upper stage as well. Do they experience a later staging event where the outer six fall away leaving the single central engine to do a long sustained burn as before presumably three of the 21 of the whole cluster were going to do? Or do we now regard all seven of the central booster's engines as sustainers alike, sharing the same supply and all burning up together after a shorter but harder second push? Considering the large mass of the upper stage and payload they have to push I'd think yes, we'd prefer the faster harder burn, unless the G load went to high--aside from excessive G loads, the faster the better. In any event they burn all the way from ground lighting to the final burn out of the central stage, three times as long at least as the outer engines do--perhaps we'd want to augment all seven of them?

As I say I've been meaning to ask you about this for weeks. Obviously it isn't the first draft design, but I have to wonder if someone on the project hasn't been thinking about the paradox of the ground-lit sustainer engine and ways and means of solving it.

And, while when I first opened up this TL and its prequel, and saw that it was about British rocketry of the 60s, I fully expected to see a lot more use of high-test hydrogen peroxide in view of its role in Black Knight and so forth, I was disappointed of course--but it remains true that in Britain there is still the most experience with peroxide as a propellant/oxidant, and so if anyone in the world would consider HTHP in this role, it would be someone migrated over from the peroxide rocket projects.

Perhaps HTHP is the wrong stuff for this role; perhaps it is better to inject LOX instead, or methane, or even to try and mix them both and hope they burn in time, or forget the whole thing and either go with a variable geometry nozzle or just accept the limits of a sea-level designed nozzle for good and all.

I still think someone somewhere on the project has been worrying about it and looking for some sort of creative solution or other. And perhaps you've got a completely different one up your sleeve!

 

[sts-200]

Originally Posted by sts-200
The Ultimate Might-Have-Been; the Reusable Constellation Rocket
There is always a certain amount of dry humor in the material you so realistically present, you know. I was bracing myself for a big disappointment but it turns out your title refers to, as it says, the Ultimate reuse scenario, recovering all three cores.

- It’s a history of a UK space program – you have to either laugh or go mad!

Meanwhile a penultimate reuse scenario that is vastly improved over anything that has happened hitherto in OTL now seems practically guaranteed, championed by none other than the same Treasury that seemed determined to do in the whole British space effort only yesterday! And everyone is sad because they only get to recover two out of three!

Until this post, I had never pictured Constellation as being three Silver Star stages in a row with the upper stage mounted on the top. Nope, I pictured them as being in a symmetric triangular cluster of three, with the upper stage stuck between them equally on the centerline of the triangular prism their centers would define. I suppose I'm just silly.

-No, not silly, it’s a valid configuration, however the in-line has its advantages. As I have alluded at various point in the story, rockets aren’t very “smooth” in flight, they bend, stretch and bounce about in a variety of potentially destructive ways. With the inline design, the vibration/flexing of the outer two can (at least partly) cancel each other out, not transmitting as much stress to the central core and upper stage. Although the details are very different, the Shuttle’s SRB attachments worked in a similar way, flexing up and down by several inches even in normal flight.
With a triangle, the three cores would be linked in a more complex way, with the action of one always affecting both the other two and the upper stages.

In view of this confusion I can see how you might have found some of my earlier suggestions quite unintelligible.

One of the things I've meant to comment on for months now has been the scheme to drop the outer six of the seven Orion engines, followed by the later plan to try and recover these dropped engines for reuse. (If you ever sketched how the capsules containing pairs of them were supposed to look and work, I'd like to see them!) It was apparent to me what the motive was; the seven engines are identical, yet one of them burns much longer than the other six, implying waste of potential for the majority unless they are used again.

-Yes, that one didn’t work (or perhaps, not enough effort was put into making it work), so they are trying again, only this time aiming to recover the whole core not just the engines. Sorry, no sketches of that one, it was a bit of a throwaway idea – exactly the sort of thing they would have thought of, before other problems got in the way.

Have you heard much about proposals for Thrust Augmented Nozzles? IIRC it is a concept patented OTL by Aerojet, but not yet to my knowledge employed anywhere. The basic concept is, introducing some sort of additional propellant into the nozzle of a rocket engine. As I've seen it presented the examples speak of combustible mixes.

-I have indeed, it looks like a good idea. Like several thrust/efficiency improvement schemes over the past 50 years it will be interesting to see if it ever makes it into service. SSTO has always been tantalisingly close and TAN is one attempt to make the design close. I’m sure shock interactions in the nozzle and the two sets of pumps make the TAN concept interesting (in the “may you live in interesting times” sense) although the cooling should be easier than with an aerospike - another promising idea that came to very little.
REL, the folks behind the “Skylon” spaceplane concept are also proposing a nozzle similar to a TAN design; although I don’t believe they plan on running both systems simultaneously, they have an air-breathing outer with a rocket inner.

As I'm sure you're well aware, a nozzle that is designed for optimal performance in a vacuum is at best going to underperform at sea level, and most likely cannot be used at all, because the design that makes the gases expand to the optimum degree in vacuum will fail to do so at sea level; the back pressure of the atmosphere will impede the flow and in particular cause the boundary layer actually flowing along the nozzle inner surface to be forced back up from the rim. This is bad enough, meaning the thrust and thus effective ISP as well of the exhaust is lowered, but worse, that forcing back inside the inner rim is unstable; the fluctuating boundary makes for resonant waves in the nozzle which can destroy it. Therefore engines that are going to be lit on the ground must have shorter nozzles that compromise available thrust.

As this applies to Orion and the Black Anvil/Silver Star, all seven engines are lit on the ground and must therefore have the short nozzles. If all of them shut down at the same time, this is just the way it must be. But the center engine of the cluster is meant to keep burning and operate well into vacuum; it is a pity it must suffer the liability of sea-level optimized nozzles. But what else is to be done?

-Yes, they have shortish nozzles with an E.R. of 22, and that only possible due to the high (for the early 60s) combustion chamber pressure, modelled at 85bar. Exit pressure would be about 1/3bar, which would be close to separation. Fitting a bigger nozzle to the centre engine isn’t possible, there is no room. They avoided having to use two different engine designs by using the more complex pre-burner high pressure design.

Some have proposed making variable-geometry nozzles of course, sliding a nozzle extension down to lengthen it once it has risen high enough. This strikes me as clumsy but it has been done. This would moderately augment the thrust at high altitude, but at obvious costs and risks.

-Its never been done on an engine while it is running (at least, not operationally). Always struck me as a desperate attempt to squeeze a bit more performance out of a vehicle, often when some other bit underperforms. If they’d just made the whole thing 10% bigger in the first place… but then the accountants get in the way.

The proposal to make Thrust Augmented Nozzles suggests that instead, one can go ahead and design the nozzle for high-altitude operation, but when firing it at sea level, introduce additional gas flow around the rim, to fill in the space that otherwise would be pushed back and unstable with a stable augmented flow. This not only allows for optimum efficiency at altitude, it actually raises the total thrust right when we want it the most, at launch. As the rocket rises into thinner air the augmented flow is throttled back and eventually stopped and the rocket proceeds as a vacuum-optimized version on its main chamber propellant alone. It obviously requires extra propellant and thus the mass flow is raised, while the combustion and expansion is not as efficient and so the thrust is not increased in proportion--which is to say, ISP is lower. (However, in view of sea level ISPs being always significantly lower than vacuum, it may be that the new average, lower than vacuum ISP, is actually also higher than normal sea level ISP!) But it means that as a trade-off for worse mass flow for a given unit of thrust, an engine can raise its thrust briefly beyond its nominal design maximum (a maximum also raised by the more efficient nozzle). Indeed the papers I've read talk about really large multiplications of thrust, factors of 2 or even 4!

However I'm not suggesting that here and now. What I'm suggesting is that the single central Orion engine might do with a redesign for better vacuum performance, if some extra propellant can be injected into the bigger nozzle, not so much with a view to raise the thrust to fantastic levels briefly, but simply to just fill the nozzle with something adequate to prevent the destructive overexpansion.

As I say, the Aerojet briefs talk about injecting more combustable mix, oxidant and propellant both, and burning them. They do point out that the mix need not be identical to what goes through the main chamber; they are thinking of massive augmentation of very large bell nozzles, and thus having a hydrogen engine that starts out augmented with four times its base thrust by means of a ker-lox mix, this in effect makes the engine a tripropellant model.

I wonder though, what if an Orion engine with modestly extended nozzle were to have high test hydrogen peroxide sprayed in downstream from the throat, perhaps near it or perhaps down near the rim, instead? A problematic aspect of burning a mix in the nozzle is that everything is already flowing out very rapidly; there is little time for combustion nor are conditions optimal either for it to go forward or for the resulting heat to be captured with full efficiency. Hence the lower ISP. But hydrogen peroxide molecules, upon hitting the flow of hot main chamber exhaust at any point, will surely decay immediately, releasing at any rate the energy of HTTP monopropellant, which corresponds to an ISP of 120 or so. This is with optimal expansion of course, which is not happening, but at any rate this energy release is certain and instant, so what heat there is is available to be expanded albeit inefficiently. The idea is to coat the lower nozzle with a layer of exhaust that is adequate to keep the air out and stabilize the flow; the layer of decayed peroxide at any rate serves as a virtual nozzle liner, in which the main propellant expands as much as it can flowing into dense air, getting what efficiency out of it is possible, while the solid nozzle stands ready to do a better job in the thinning upper air as the peroxide is throttled back, allowing gradually better expansion of the main flow. The peroxide might not contribute a whole lot of extra thrust but it does add something. Also, the main chamber exhaust is as you've pointed out, fuel rich, while the peroxide releases energetic oxygen atoms. These might possibly burn some or all of the unconsumed fuel, releasing more energy and thus, despite delayed reaction making the expansion of the product less efficient still, at any rate further augment the thrust a bit. And finally, the peroxide, although guaranteed to flash into a hot gas by its instability encountering the main flame, is much cooler than that main chamber exhaust; it insulates the nozzle, delaying any deterioration that heat might cause.

-Under those circumstances, you would be better off injecting more Methane/Oxygen rather than adding a separate HTP system.
Or, it you need a more powerful rocket (which they don't) make it a cruciform configuration with 5 cores and stretch the upper stage.

Of course in an expansion cycle engine that is meant to cool that nozzle regeneratively and then use the heat to drive the turbine, that's a mixed blessing at best! It would tend to rob the turbine of some of its power--to be sure the main chamber is still putting out the same standard heat and I guess that is where most of it comes from. And you have a mixed enhanced cycle with a burner assisting the heat a bit; here we could just burn that a little hotter to make up I'd think.

So if the central engine of the cluster were modified in this way, we'd wind up needing to boost a bit more mass, in the form of a reserve of hydrogen peroxide, but we'd have a bit more thrust from the center engine too at launch. And as the rocket climbs to the level where the outer engines are ditched, the thrust of the center engine would fall--but not all the way down to the standard level of an unmodified engine; it would always produce extra thrust, but at altitude at maximum and indeed improved ISP.

- The current configuration is limited by physical space (the nozzles are about 1.8m across, plus they need room to gimbal) so extending the nozzles isn’t possible. If you built a TAN Orion, perhaps you could cut it to 3 or 4 engines, which would give a bit more room for wider nozzles.

It is perfectly clear now to me that the two outer boosters of a Constellation would, under the modified reusability plan, cross-feed to the central booster, thus starving their own tanks of the remnant propellant that was going to feel the seventh engine--all seven of the outers now burning out at the same time. Thus, we would not want any of those 14 Orions to be modified in this fashion; they never rise up high enough to justify the vacuum optimized nozzle.

What is less clear is what happens to the seven engines of the central booster driving the upper stage as well. Do they experience a later staging event where the outer six fall away leaving the single central engine to do a long sustained burn as before presumably three of the 21 of the whole cluster were going to do? Or do we now regard all seven of the central booster's engines as sustainers alike, sharing the same supply and all burning up together after a shorter but harder second push? Considering the large mass of the upper stage and payload they have to push I'd think yes, we'd prefer the faster harder burn, unless the G load went to high--aside from excessive G loads, the faster the better. In any event they burn all the way from ground lighting to the final burn out of the central stage, three times as long at least as the outer engines do--perhaps we'd want to augment all seven of them?

-Your second option, the whole staging plan has completely changed. None of the booster rings are jettisoned, and both core and outers will burn all seven engines until they are shut down by the relevant low-fuel sensor. Peak G loads are quite mild, only about 4.5G just before core booster cut off.

As I say I've been meaning to ask you about this for weeks. Obviously it isn't the first draft design, but I have to wonder if someone on the project hasn't been thinking about the paradox of the ground-lit sustainer engine and ways and means of solving it.

-I’m sure they’d love to improve on it, but there won’t be any money to do so. Still, it leaves them with a fully-tested booster core that someone else has paid for.

And, while when I first opened up this TL and its prequel, and saw that it was about British rocketry of the 60s, I fully expected to see a lot more use of high-test hydrogen peroxide in view of its role in Black Knight and so forth, I was disappointed of course--but it remains true that in Britain there is still the most experience with peroxide as a propellant/oxidant, and so if anyone in the world would consider HTHP in this role, it would be someone migrated over from the peroxide rocket projects.

-HTP was still going strong on the Blue Star rockets until early ‘69 (and might still have a minor role to play). Silver Star or Constellation may be bigger and better, but they might live to regret the decision to abandon the small, cheap Blue Streak/Blue Star.

Perhaps HTHP is the wrong stuff for this role; perhaps it is better to inject LOX instead, or methane, or even to try and mix them both and hope they burn in time, or forget the whole thing and either go with a variable geometry nozzle or just accept the limits of a sea-level designed nozzle for good and all.

I still think someone somewhere on the project has been worrying about it and looking for some sort of creative solution or other. And perhaps you've got a completely different one up your sleeve!

-There’s no stopping engineers being engineers, but even the old Selene Project Committee knew that coming up with a load of exciting (expensive) ideas wasn’t going to earn them many friends. There is also far less slack in the British/French aerospace industry; there are simply far fewer people available to do the studies.
I will just say that in reality there was a lot of history between Rolls-Royce, North American Rockwell, Lockheed and BAC. Whether or not that will turn into a happy story … I couldn’t possibly comment.

 

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The Dawn of a New Age

Mar-69 Overseas
NASA launches SA-304 with a dummy version of its Orbital Lab space station.
270’ tall at liftoff, with tanks up to 26’ in diameter, the Saturn successfully places its 65t payload into the target orbit. Venting of propellant from the third stage is used to target the steel structure to safely burn up over the Pacific on the second orbit.
At the end of the flight, the Space Agency is able to declare the Saturn III "operational".


Apr-69
SERP-4 / Diamant B
Materials test satellite. An improved version of the French Diamant launcher puts an 88kg payload into a 341x362km orbit from Kourou. The satellite is used to measure changes in the physical, thermal and electrical properties of several alloys and plastics when exposed to space conditions. Data is returned until June 1970.

Apr-69 Overseas
The Boeing 7227 prototype makes its first supersonic flight, flying at Mach 1.5 for half an hour. Future flights will expand the speed and range envelope of the prototype. The production versions will be capable of achieving Mach 2.2 with a 4,000 mile range. Boeing promise to start deliveries to customers in 1972.

Apr-69
The Selene Board completes the drafting of its first full year budget plan, covering 1970.
UK based operations will require direct expenditures of £103M, a real increase of 8% on the 1969 budget. French expenditures are planned at FFr1,317M (equivalent to about £106M. 1970 will be the first year the French officially spend more than the British). Australian expenditures are expected to be the equivalent of £17M.

[A brief retrospective - If Selene budget numbers always seem small, that’s because they are. The numbers quoted to the public at the time were invariably "subject to revision" and much of the Selene Project was accounted for on a marginal basis - i.e. the rockets were in production, the factories already existed, how much did it cost to “build another one”? In addition, the contractors used a wide variety of costing methods, the only point of commonality being that they were all too low.
In 1983, the British government commissioned economist Professor K. Fellingham to study the true cost of Selene. His report of 1984 is regarded as the closest we will ever come to knowing the real cost of the Project.]

FA-3
Black Anvil flight test from Rainbow Beach. A short range, high altitude profile is used to aid in the tracking of the RVGC and to allow the return of more telemetry. Apogee 438km. The RVGC and 4 dummy RVs are tracked over 3,305mi until they re-enter over the Pacific (the remaining RV positions were occupied by test equipment, and there are hints in a declassified document that a real RV was also carried).


OTR-22
Blue Streak test from Benbecula. Reworked missile with new fuel line and engine components replacing fatigued parts. Range: 1,525mi, impact 5,850' from target point. Unusually large error found to be due to a misalignment of the post-boost guidance system.


Selene Astronaut Mike Suttler completes the first simulated lunar landing in the new vehicle training facility at Biscarosse. This large hangar contains full scale mockups of the PROM and VDL spacecraft control systems, linked to banks of computers which feed data back to the displays and instruments on board. Launches, manoeuvring in space and lunar landings can all be simulated. An early use of the facility will be in the development of VDL controls themselves and the software that will help the astronauts land on the Moon.
This first successful landing was part of the testing process for the facility, not really a training or development exercise. In the simulation, Suttler landed 22km from the intended point, having semi-manually controlled the VDL all the way from orbit. In real life, he would probably have crashed while making a long, low approach. A landing 22km from the cargo module would also be a problem, as the crew would not be able to refuel their PROM for the return to Earth.

May-69 Overseas
NASA's Surveyor 7 probe fails shortly after launch from Cape Canaveral. The Atlas-Centaur booster veers off course and is destroyed by the Range Safety Officer.


May-69
Aurora 3 / S-118
Test of a PROM spacecraft with all the improvement s made since the failure of Aurora 2A. The delay 2A has given engineers at HSD and its subcontractors time to improve many of the systems, not just the parachutes and generator exhausts. The PROM has a fully developed version of the general purpose computer (the SCC), running improved software which allows for much more sophisticated control from the ground.
The mission plan calls for a long duration test flight to thoroughly shake down the automatic systems on board. The Silver Star rocket injects the spacecraft into a 179x183km orbit. The PROM/VDL-A spacecraft separates for a four orbit coast, with the frame of the VDL-A cast off during the first orbit. After severl thruster burns, two orbit changes are made using the new main engine. The J-650-102 is a close relative of the engine now flying on Silver Star upper stages, adapted for use on the PROM with parallel-redundant valves and a more sophisticated electronic monitoring system.

The SCC stops accepting commands from the ground at T+16:37. The fault is traced to a faulty radio relay at Mission Control (ground stations in the Bahamas and Australia have no problems communication with the PROM) and full control is re-established at T+19:32. The PROM continued to return data when in range of the various ground stations and the automatic on board systems kept the ship stable and functioning normally.

Aurora 3’s RM is fitted with two TV cameras which are able to return images of the Earth and the inside of the spacecraft when it passes over the French ground station near mission control at Biscarosse. On day 2, one of these transmissions is broadcast live in the UK and France as the spacecraft flies over the Mediterranean. Good quality images of the whole of France, stretching north to the south coast of the UK are broadcast for three minutes, giving TV audiences in both countries their first live view from space and providing a sense of orbital speed; the spacecraft passes along the entire length of the south coast of France in barely a minute. It is the first time a non-US spacecraft has returned live images from space.

Further systems and engine tests are run over the next two mission days. The spacecraft is aligned for re-entry at T+77:19 and fires its J-650 engine a few minutes later. A peak of 3.7G is recorded on re-entry, and the capsule splashes down off the Australian coast at T+78:14, all three parachutes deploying exactly as designed.

May-69 Overseas
The Soviet Soyuz 5 mission sets a new endurance record. The two crewmen complete a 17 day 6 hour mission, making 276 orbits of the Earth.


May-69
Construction of the first six Black Anvil shelters is accelerated. Revised MoD plans now call for the early deployment of 6 Black Anvil missiles in 1970, with a further 8 missiles in 1971. Although not widely publicised, as part of cost-cutting measures, the Christmas Island-B sites (in the Indian Ocean) and Malden Island sites were “de-prioritised” (a.k.a. cancelled) in late 1967.
Sites on Christmas Island-A (in the Pacific) and on Ascension remain under construction. A wide-ranging study in 1968 suggested basing missiles in locations as diverse as Western Australia, northern Canada, the Falkland Islands, the US-leased islands of Chagos or on various Highlands and Islands within the UK itself. Most of these have ruled themselves out on diplomatic or cost grounds, however the Australians agree to host six silos on the Maralinga Range (under an extension of the Anglo-Australian Commonwealth Deterrent Agreement) and another twelve will be built in the far northeast of Scotland and the Orkneys. Six on Ascension Island and eight on Christmas Island will complete the Black Anvil deterrent installation.

The problems with Blue Streak are only partly solved. There is no avoiding the fact that the missiles are simply nearing the end of their fatigue lives and need to be retired. Of the 39 supposedly active sites, only 27 have operational missiles, a situation which is unlikely to improve.


Jun-69
Installation of three new ICL System 4 computers at the mission control and training facility at Biscarosse is completed. These will be used to supply real-time data and predictions to mission control for future manned and unmanned flights. A similar computer at the Vehicle Training Facility will be used to improve mission simulations that will be used for training.

The Selene Board is briefed on the outcome of the Aurora 3 mission. Minor technical issues encountered during the flight will be worked on before Aurora 4. The significant command problem encountered early on was due to a fault on the ground, not the spacecraft. Had there been a crew on board, they would have been able to fully control of the spacecraft at all times. Launch and entry performance was nominal. There are no objections to launching a crew on the next flight.

The public relations and press office formed by the Selene Board starts its first publicity campaign. In an effort to inform the public and make the Project more understandable, it includes mobile cinema tours, magazine and newspaper articles rather than the more traditional lectures and technical books.
In the UK, events are often organised alongside others sponsored by the Ministry of Technology on "High Tech" subjects such as nuclear power, computer controls and automotive technology. The newly formed Selene Film Unit puts out a series of short 15 minute films focusing on different aspects of the Project and how they affect everyday life. Although they now appear rather quaint and stilted, like the much-ridiculed "Public Information Films" of the time, they were popular and do a great deal to make the Selene Project seem more relevant to the public.

Jun-69 Overseas
NASA launches the World’s first space station “Spacelab” on Saturn III rocket SA-305. The launch goes as planned and the 60 ton Lab is injected into a 350km orbit at a 45degree inclination, which will allow its instruments to see almost all of the inhabited surface of the Earth.
The next day, the three crew of Apollo 9/S are launched and dock with the Lab after a 9 hour flight. They spend 28 days in space, setting a new endurance record. More importantly, they make three spacewalks, deploy a 45kg sub-satellite and conduct Earth observation experiments using the Lab’s Infrared film cameras. The mission plan has to be revised on day 18 when one of the two solar arrays fails, leaving the Lab short of electrical power; a problem that is likely to affect future missions to the station.

Jul-69
Mission planners and Project managers start to rework their schedules and flight plans to deal with the changes in Constellation development. It is known that CLV flights will start later than was originally planned, however it is believed that the savings in both cores and cost offered by the recoverable "wing boosters" mean that it may be possible to fly more frequently and conduct a more comprehensive test programme once the rocket is available.

The development of pressurised lunar rovers and a mobile laboratory for use on later Selene flights is cancelled. Contractors are required to document the present state of work and then close down any further development within 28 days. When Selene was started, it was assumed that there would be the need for extensive exploration after the first few landings; there had even been an idea for a “Equator to Pole” drive, exploring dozens of different terrains during both lunar day and night time operations (lunar nights are cold, but thanks to the effects of Earthshine they are not very dark, at least on the nearside). These ambitious plans are now formally scrapped. Two-launch missions will visit a variety of sites before any larger three-launch missions are considered, these preferably in co-operation with the US or other European nations. The only lunar surface vehicle left in development is a battery powered open rover for use in short range exploration.

Revised plans for upcoming Aurora flights are circulated among Project staff. After several false starts, it is felt inadvisable to publicise the plans too widely. The Selene press office will instead release details of upcoming flights a few months in advance.
Aurora 4 - First manned flight, a 3/4 day mission to test the PROM and its systems (August ‘69)
Aurora 5 - 4 day flight, to include a spacewalk or possibly two (November ‘69)
Aurora 6 – 7 day expanded version of the Aurora 5 mission (January '70)
Aurora 7 – 7 day mission, taking a fully fuelled PROM to a high Earth orbit for deep space navigation tests (March/April '70).
Auroras 8-12 will be flown from late 1970 using VDL-B development versions of the lander. These will test longer mission durations and verify the performance of many of the VDL systems.

The crew of Aurora 4, Commander Sebastiane Lehart and Navigator Michael Kington are presented to the public at a press conference in Paris. These former Aeronavale and RAF officers were selected in 1966 as members of the first eight Astronauts to be trained under the Selene Project.

Jul-69 Overseas
The US Space Task Group reports to President Nixon with a range of options for the future of NASA spaceflight.
They present the President with three options:
- a $5Bn per year "expansionary" programme, including manned lunar flights, a large space station, a reusable shuttle and a Moon base by 1980.
- a $3.8Bn per year "progressive" programme, a slight increase on the current NASA budget of $3.3Bn. This calls for two more small space stations in Earth orbit, then a series of lunar landings in the period 1974-7 and a reusable shuttle in service by 1980.
- a $2.8Bn "minimal" programme, which would fly 3 "Orbital Lab" type stations in the 70s, serviced by Apollo spacecraft. There would be a greater focus on unmanned space exploration.
The report is accepted with considerable interest by the White House, although a decision is not expected before the end of the year. Privately, NASA and the STG have prepared two additional options, to be introduced depending on the direction of the discussions in the months ahead.
- a "Super Expansionary" option, at $6.5Bn, which adds a reusable nuclear space tug, orbital propellant depot and the goal of a permanent Moonbase by 1980.
- a "Shuttle-Station" option, at $3.2Bn, which seeks to fly an improved “Orbital Lab" type station and develop a reusable shuttle by 1975.

Jul-69
In an internal document at BAC, design engineers point out that the new staged booster design for the Constellation launch vehicle means that the central core will have to be strengthened to cope with the mass of the upper stage on its own. This means that one of these strengthened cores would be capable of flying an ECPS test flight without the "wing boosters". This concept was dismissed earlier in the year when it was shown that unmodified cores were not strong enough to support the ECPS.
They point out that this change means that the recoverable boosters might not be needed at all, as single core ECPS tests would save a sufficient number of outer cores to allow the schedule to proceed without having to reuse any of the boosters.
The document is quickly "filed" and the authors told to keep quiet, as it is not in the firm's interest to loose the funds it expects to receive for the development of the recovery system.

FA-4
Black Anvil test from Rainbow Beach. Known to have been the first attempt to deploy 8 RVs on one flight. The missile’s sustainer engine shuts down 299s into the flight. The instrumented RVGC separates a few seconds later, triggered by the loss of thrust. It attempts to manoeuver towards its first pre-programmed release point, but has nowhere near enough fuel to do it. None of the RVs separate and the RVGC burns up over the Pacific. Telemetry is received until shortly before it enters the atmosphere.

Aug-69 Overseas
Funding for the US nuclear rocket program is to be wound down in 1970. The program has been working on high efficiency engines for nearly 10 years, but it is still believed to be 5 years away from delivering a flightworthy version. Lab based research into the technology will continue.
The halting of this somewhat secretive project is largely unnoticed by the public, but is a major blow to NASA's hopes of a more ambitious space program; the agency's hopes for lunar bases and ideas for Mars flights all depend on nuclear rockets to launch the huge payloads that would be needed.

Aug-69
A SNECMA R-1065 prototype engine completes its first full duration test. The R-1065 will be used to propel the VDL into lunar orbit and down to the surface.
The test includes a demonstration that the engine can safely throttle to 65% of full power - future tests will be used to show throttling to 20%. Even better news comes in the form of the performance figures; the engine demonstrated a specific impulse of 422s and maximum thrust of 6,126kgf, both comfortably above the specifications of 420s and 6,000kgf.

BOAC agree to provide passenger services to British Selene Project personnel in part return for the continuation of government subsidies on routes to the Far East and Australia.
One object of this is to take the strain off the Princess flying boats. Until now these have been used to maintain a regular service, irrespective of whether a booster core needs to be transported. Princess flights will now only be made when a Black Anvil core needs to be flown out to Australia. British staff are relieved to be able to fly on relatively comfortable airliners, instead of the noisy and slow flying boats. French personnel have enjoyed a similar arrangement with Air France since 1967.

Engineers at Rolls-Royce conclude that the Orion engine failure on FA-4 was caused by a faulty sensor in the engine's hydraulic system. The sensor showed that hydraulic pressure had fallen too low to allow the engine to be gimballed. This triggered a fault signal to the flight control system, which then shut down the faulty engine to prevent the vehicle spinning out of control. The system was designed to allow the 7 engine missile to continue flying if one of the booster engines failed.
Safety considerations with civilian launches have led to the system being left active throughout the flight, as it is thought important to be able to safely shut down a faulty engine in the final seconds of flight on the chance that the upper stage can still boost the payload into orbit. On a missile flight, the system should be switched off when the booster pack is dropped, as a military missile may as well continue as long as possible, on the chance that there is no overall failure.
In this case, the missile would probably have continued without any problems, as other telemetry suggests that the hydraulic system did not actually fail, it was the only the sensor that was faulty.
Further Black Anvil/Silver Star flights are cleared to proceed, subject to close inspection of similar sensors that are used on the rockets.

 

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There may not be any more updates for a few days, but I will leave you with a fun one:

 

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Aurora 4

Tuesday 9th September 1969​

After delays in the countdown for the launch and delays of more than a year in the programme, at 16:10 Australian Eastern Time, a Silver Star rocket lifts off from Rainbow Beach carrying the first manned Selene spacecraft.

Launch delays from earlier in the day mean that sizable TV audiences in Britain and France are awake to see the launch, broadcast live on television via Hermes in the UK and across most of Europe via the Eurovision link. Spectacular tracking shots show the rocket for over 3 minutes after launch, clearly showing the booster pack separating at 152s and the big payload fairing falling away a few seconds later.

Six minutes and fifty one seconds after liftoff, the sustainer engine shuts down and Commander Sebastiane Lehart and Navigator Michael Kington become the first British and French astronauts.

Their PROM spacecraft and the framework of the VDL-A separates from the booster core one minute after orbit is achieved. Thrusters are tested while still attached to the inert structure of the VDL-A, before the PROM separates half an orbit later for its primary mission. Over the next seven and a half hours a comprehensive checkout of controls and navigation systems is performed, leaving the ship in a 181x206km orbit while the crew take an abbreviated rest period. The tests have run late and mission control is keen to keep to the timeline. After so many delays and problems within the Selene Project, everyone is keen to demonstrate as much as possible during this first flight.

There are Too Many Captains on this Ship – Day 2 in orbit

After a five hour rest and their first meal in space, Lehart and Kington prepare for the main events of day 2; four burns of the PROM's J-650-102 main engine.
During the morning, two are successfully completed under the control of the PROM's computer. Communications between the guidance and vehicle controllers on the ground and the crew in orbit proves very difficult during preparations for the third burn, as everyone keeps talking over each other on the poor quality radio link. Lehart complains about the standard of radio discipline and matters improve for a while, but confusion re-asserts itself when a call is missed by the crew as the communications link is lost over the Indian Ocean. Nevertheless, the third burn is completed successfully, albeit one orbit later than planned.

Later in the day (they are now about 3 hours behind schedule), just before the fourth burn, a mistake by Commander Lehart overwrites several key control parameters in the PROM’s computer. Mission controllers and crew restart the preparations, but this time Michael Kington cannot complete the realignment of the guidance system; he is unable locate one of three stars through the navigation sextant. The exhausted crew then mishear a command to change telemetry relay systems, resulting in Biscarosse controllers loosing their "view" of the status of most of the ship’s systems. Interrupted by the lack of communications while over the Pacific, it takes half and hour of checking to find and correct the mistake.
The demand by ground control to continue the engine burn sequence is overruled by Commander Lehart at T+28:27, after he and Kington have been working for nearly 16 hours straight and having had little rest since launch preparations started 40 hours ago. Disagreement between ground and spacecraft starts to become serious until Lead Flight Controller John Armitage halts discussion and orders ground control teams to help the crew prepare the spacecraft for an 8 hour rest period, to start at T+30:02.

No Peace for the Wicked – Day 3

The alert buzz of the Master Alarm wakes the crew at T+35:38. Generator and voltage warning lights flash, informing them that the No.2 closed-cycle generator is no longer producing any power.
Despite a delay in responding due to some mission controllers being stood down during the rest period, crew and ground work well to switch systems over to the still functioning No.1 unit, which can meet the entire power needs of the PROM (except during a few periods of very high power use).

Their sleep now interrupted, controllers and crew decide to proceed with the Day 3 flight plan - an attempt to demonstrate precision flying by making a rendezvous with the inert VDL-A structure, which was jettisoned shortly after launch but is still in orbit a few miles below the PROM. During this time, Electrical and Spacecraft Controllers on the ground continue to analyse the generator problem.
Setup for the rendezvous is made with computer assistance, with the crew taking manual control during the final segment. Their fuel use during this final approach exceeds the flight plan by a factor of 2.5; hardly a problem, given that the PROM has 7.3t of fuel remaining, but not encouraging for future flights where fuel economy will be of greater importance. Heavy power use from the heaters and pumps needed to supply the RCS thrusters exceeded the single generator’s capacity and started to drain the PROM's auxiliary batteries.

At T+40:07 the Master Alarm sounds again; the other generator has cut out, throwing all the PROM's electrical load onto the batteries. An attempt to “station keep” with the VDL-A stage is abandoned while crew and controllers focus their attention on this latest problem. The situation demands urgent action, but the crew are not in immediate life-threatening danger; on battery power alone, the PROM can operate normally for about 4 hours. This gives some time to try to fix the generator, but unless this can be done within an hour, the mission will have to be abandoned and preparations for re-entry must commence. Relief comes just in time, at T+40:41, when the crew, working calmly through their checklists, succeed in restarting generator No.1.

Back on Earth, system engineers and medics at mission control in Biscarosse have become increasingly concerned over the progress of Aurora 4, and the Mission Controller's insistence that everyone proceed with the flight plan in spite of the obvious problems. At a hastily arranged meeting of senior flight controllers, medics wish to bring the exhausted crew home as quickly as possible, systems staff want to shorten the 4 day flight, while Project managers and navigation specialists want to fly the full mission. The generator problems at T+40:07 interrupt the meeting and when it resumes a decision is quickly taken; the crew will be given a rest, then conduct a shortened navigation exercise (originally planned for day 3) before preparing for re-entry on the 37th orbit, that is to say in about 14 hours’ time.

To help them sleep and reduce the load on the overstretched generator while the batteries are charged, the crew darken their ship at T+43:15 for a 5 hour rest period. With no interruptions other than the hiss of the radio, both report that they managed some fitful sleep.
After a quick "breakfast", a somewhat random assortment of pre-packed food thanks to the topsy-turvy flight plan, the crew start a navigation exercise. Over the next 5 hours, they repeatedly reset and fine tune their guidance system, checking it against ground and star references. An experimental ground based radio location system is also tested during two passes over Australia.

Setup for re-entry starts at T+53:32 once the tracking exercise is complete. The PROM computer does not accept the entry parameters correctly (or rather, someone made a mistake when entering them) and entry is delayed by one orbit while the program sequence is checked and repeated. Re-entry procedures begin at T+55:28 with an 8s burn of the main engine. The PM is jettisoned three minutes later and the RM re-enters gently, with a peak of just 3.72G being recorded. Splashdown is in the Indian Ocean at T+56:02, within 8 miles of the recovery ships HMAS Melbourne and RFA Engadine.

In private, controllers, managers and astronauts know that there is a lot of work to do. Aurora 4 was a fairly simple mission, certainly in comparison to some of the later flights that are being planned. All they had to do was go into space, orbit for a few days, control the ship, make a few observations and come home, and yet there were a host of technical and operational problems.

Publicly, the flight is hailed as a spectacular success. Despite some “teething troubles”, most of the primary mission was completed. The PROM itself behaved well and the crew demonstrated their ability to fly the ship both manually and automatically. They successfully navigated in space and performed the complex and precise manoeuvres needed to achieve a rendezvous in orbit.

Having passed this first test, the Project will now proceed towards its next major goal: Spacewalk.