MrP
Banned
A highly original and well-written TL, great job so far!
Absolutely superb illustrations, too. Kudos to @nixonshead for his work.
Absolutely superb illustrations, too. Kudos to @nixonshead for his work.
Right Side Up: A History of the Space Transportation System
- Thread starter Polish Eagle
- Start date
Shevek23 wrote:
Mercury used H2O2 just FYI. Gemini was designed to use H2O2 but instead installed "off-the-shelf" hypergolic thrusters as did Apollo, both in order to reduce system design and construction time. If Apollo were to be used "longer-term" (aka APP or extended Lunar operations) there was study and consideration of using an H2O2 system instead of the hypergolic system to extend the thruster life, (hypergolic propellants erode the seals and pipes over time and any leaks could be deadly in enclosed spaces which were being proposed for various space station and lunar "hangers" at the time) and reduced maintenance and refueling issues. (H2O2 boils away faster and cleaner in a vacuum than most of the hypergolic propellants)
5C/40F isn't really 'near freezing' fluid wise, that's "air conditioning" not cryogenic handling
90% is actually quite stable as long as it's vented properly with 90%/91% falling to around 84% over a 17 year period stored OUTSIDE in Texas with no issues. (Paragraph XI, page 8: http://www.hydrogen-peroxide.us/history-US-General-Kinetics/AIAA-2005-4551_Long_Term_Storability_of_Hydrogen_Peroxide.pdf) Note vented drum storage in figure 11, 1 to 6 years which consisted mostly of unstabilized and torpedo H2O2 which was mostly used/tested in the 50s.
Ingestion of or skin contact of hydrazine is toxic even in very small amounts. I've seen numerous arguments that you could "wash your hair" in hydrazine and be fine and supposedly this is attributed to people who work with the stuff but as I happen to work both with hydrazine in general AND people who actually 'work' with stored hypergolics I have yet to find one who will support that assertion in any respect. Ingestion, (including inhalation of vapors) is deadly. Skin contact is very dangerous to the high degree with exposure to an open wound considered deadly. H2O2 on the other hand is considered 'dangerous' (irritant) but not fatal in exposure unless doused in massive amounts (corrosive) to which treatment is dilution with water. (Distilled preferred but not required) Vapors are NOT considered a hazard though increased oxygen in the air can increase fire hazards.
I can find nowhere which shows 'water' as being a "catalyst" for H2O2 only "contaminated" (water with dissolved catalyst components in it AND only at certain, and usually very high concentration levels, point of fact the ONE warning I found was water contaminated with copper to the level it was unhealthy for human consumption and a toxic alert level in and of itself) water. Water is the recommended dilution mechanism and it is recommended to apply immediately.
HTHP and kerosene is a possible bi-propellant as you already have the kerosene on-board. Arguably you could use LOX/Kerosene thrusters using on board propellant BUT HTHP/kerosene using a catalyst pack system allows a much wider range of thrust since you have both the mono-propellant HTHP and bi-propellant HTHP/Kerosene available. Some work was done during the 70s on self-pressurized H2O2 systems but was dropped due to the concentration on hypergolic propellants. This was a basis of later work done on piston pumps and VPAC, along with a more advanced H2O2 self-pressurization system in the 1990s.
As far as I can find the main reason for the continued use of hypergolic propellants is availability and cost compared to developing, (re-developing for the most part) an H2O2 system from scratch due to all operational engines being long out of production.
Randy
Mercury used H2O2 just FYI. Gemini was designed to use H2O2 but instead installed "off-the-shelf" hypergolic thrusters as did Apollo, both in order to reduce system design and construction time. If Apollo were to be used "longer-term" (aka APP or extended Lunar operations) there was study and consideration of using an H2O2 system instead of the hypergolic system to extend the thruster life, (hypergolic propellants erode the seals and pipes over time and any leaks could be deadly in enclosed spaces which were being proposed for various space station and lunar "hangers" at the time) and reduced maintenance and refueling issues. (H2O2 boils away faster and cleaner in a vacuum than most of the hypergolic propellants)
5C/40F isn't really 'near freezing' fluid wise, that's "air conditioning" not cryogenic handling
90% is actually quite stable as long as it's vented properly with 90%/91% falling to around 84% over a 17 year period stored OUTSIDE in Texas with no issues. (Paragraph XI, page 8: http://www.hydrogen-peroxide.us/history-US-General-Kinetics/AIAA-2005-4551_Long_Term_Storability_of_Hydrogen_Peroxide.pdf) Note vented drum storage in figure 11, 1 to 6 years which consisted mostly of unstabilized and torpedo H2O2 which was mostly used/tested in the 50s.Ingestion of or skin contact of hydrazine is toxic even in very small amounts. I've seen numerous arguments that you could "wash your hair" in hydrazine and be fine and supposedly this is attributed to people who work with the stuff but as I happen to work both with hydrazine in general AND people who actually 'work' with stored hypergolics I have yet to find one who will support that assertion in any respect. Ingestion, (including inhalation of vapors) is deadly. Skin contact is very dangerous to the high degree with exposure to an open wound considered deadly. H2O2 on the other hand is considered 'dangerous' (irritant) but not fatal in exposure unless doused in massive amounts (corrosive) to which treatment is dilution with water. (Distilled preferred but not required) Vapors are NOT considered a hazard though increased oxygen in the air can increase fire hazards.
I can find nowhere which shows 'water' as being a "catalyst" for H2O2 only "contaminated" (water with dissolved catalyst components in it AND only at certain, and usually very high concentration levels, point of fact the ONE warning I found was water contaminated with copper to the level it was unhealthy for human consumption and a toxic alert level in and of itself) water. Water is the recommended dilution mechanism and it is recommended to apply immediately.
HTHP and kerosene is a possible bi-propellant as you already have the kerosene on-board. Arguably you could use LOX/Kerosene thrusters using on board propellant BUT HTHP/kerosene using a catalyst pack system allows a much wider range of thrust since you have both the mono-propellant HTHP and bi-propellant HTHP/Kerosene available. Some work was done during the 70s on self-pressurized H2O2 systems but was dropped due to the concentration on hypergolic propellants. This was a basis of later work done on piston pumps and VPAC, along with a more advanced H2O2 self-pressurization system in the 1990s.
As far as I can find the main reason for the continued use of hypergolic propellants is availability and cost compared to developing, (re-developing for the most part) an H2O2 system from scratch due to all operational engines being long out of production.
Randy
I like Peroxide HTHP either as mono-propellant for reaction control systems or as bi-propellant HTHP/Kerosene for rocket engine there are Clean and easy to handle Propellants
and as bi-propellant HTHP/Kerosene it feature lower combustion temperature, for turbo pump you can use the HTHP to powert it (with help of Silver catalyst)
or goes for high performance stage combustion cycle
NASA and alternative RCS/servis module Propellants
2004 during Crew Exploration Vehicle project they look for alternatives for the toxic hypergolic propellants
like HTHP were also Lox/methane and Lox/Alcohol (V2)
but they were drop do infancy of those propellants in US rocket technologies.
in 2006 CEV became ORION with toxic hypergolic propellants in it's Service Modul and capsule
in 2009 ORION loose it Service module after Termination of Constellation program only in,
2011 it get ESA ATV as new Service module and surprise it use also toxic hypergolic propellants
Why ?
-First ATV was original build for Unmanned flight
-Second the French rocket engineer have long tradition with toxic hypergolic propellants
But they have work in HAZMAT protective suit
and as bi-propellant HTHP/Kerosene it feature lower combustion temperature, for turbo pump you can use the HTHP to powert it (with help of Silver catalyst)
or goes for high performance stage combustion cycle
NASA and alternative RCS/servis module Propellants
2004 during Crew Exploration Vehicle project they look for alternatives for the toxic hypergolic propellants
like HTHP were also Lox/methane and Lox/Alcohol (V2)
but they were drop do infancy of those propellants in US rocket technologies.
in 2006 CEV became ORION with toxic hypergolic propellants in it's Service Modul and capsule
in 2009 ORION loose it Service module after Termination of Constellation program only in,
2011 it get ESA ATV as new Service module and surprise it use also toxic hypergolic propellants
Why ?
-First ATV was original build for Unmanned flight
-Second the French rocket engineer have long tradition with toxic hypergolic propellants
But they have work in HAZMAT protective suit
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your right, i forgot mention that option, in theory you could store orbital H2O2 / kerosene for years !
and there anther option In-situ production of H202 like on Mars.
and there anther option In-situ production of H202 like on Mars.
Well, I finally finished reading this thread.
Very interesting stuff. With all the discussions we've had about what the Saturn-Shuttle and Flax-Shuttle would be like, I don't think I've ever seen anyone propose a Saturn-Flax-Shuttle.
I have to say, I am worried that the US aerospace industry will be able to maintain the capability to repair boosters or build new Lifters. Unless there is more political will to support the manufacturers and keep key production lines and facilities open, I have a feeling that quality will decline and costs rise for existing Lifters and buying new Lifters will become impossible.
This thread has been a vivid reminder of just how much of a pain LH2 is. It really makes me wonder what anyone was thinking when the proposed the "hydrogen economy" wheeze.
Does anyone know why the SIVB was so expensive? The stretched SIVC being more expensive than the Lifter is jaw-dropping to me.
And is the relatively low cost of the Lifter given in the L5 Society quote the cost of the use a Lifter for one launch or the cost of an entire Lifter, new off the assembly line?
With regards to Shevek's considerations of a Soviet "Liftersky", so far as I am aware, the chance of the NK-15 or NK-33 engines getting on new rockets were vanishingly small. Glushko seems to have had it in for the engines. If the Proton rocket fails spectacularly when the Politburo visit to watch the launch (forcing them to run away from the toxic cloud) as OTL, the Soviets will definitely want to replace the Proton. Honestly, with the US program going the direction it is, I think the Soviets would opt for the 11K77 medium-lift vehicle (what became OTL's Zenit-2) and the 11K37 heavy-lift vehicle (which OTL never got off the drawing board). The Soviets were planning to make the family of boosters with re-useable first stages anyway and their designs don't need to be manned the way the US Lifter does. I suspect the Soviets would also look into developing a high-power LH2/LOX upper stage, since the Politburo were feeling inferior to the US in LH2 technology and wanted to catch up.
Without the US building a giant monster of a shuttle, Glushko has no excuse to push for his Mars rocket, and the rest of the Soviet space establishment sans-Barmin (who will want a moon rocket about the size of Energia for the Barmingrad moonbase) will push Glushko to get behind the rockets THEY wanted - which would certainly be equal or smaller than the 11K37 with a LH2/LOX upper stage. As such, I expect Glushko would fight all the harder to get his big rocket engine to make sure he had his page in the history books secured.
I suspect that the main area Soviet ambition will be pushed forward (rather than back) by the changes in the US is that they'll look harder at how to make the Zenit first stages fly-back stages.
fasquardon
Very interesting stuff. With all the discussions we've had about what the Saturn-Shuttle and Flax-Shuttle would be like, I don't think I've ever seen anyone propose a Saturn-Flax-Shuttle.
I have to say, I am worried that the US aerospace industry will be able to maintain the capability to repair boosters or build new Lifters. Unless there is more political will to support the manufacturers and keep key production lines and facilities open, I have a feeling that quality will decline and costs rise for existing Lifters and buying new Lifters will become impossible.
This thread has been a vivid reminder of just how much of a pain LH2 is. It really makes me wonder what anyone was thinking when the proposed the "hydrogen economy" wheeze.
Does anyone know why the SIVB was so expensive? The stretched SIVC being more expensive than the Lifter is jaw-dropping to me.
And is the relatively low cost of the Lifter given in the L5 Society quote the cost of the use a Lifter for one launch or the cost of an entire Lifter, new off the assembly line?
With regards to Shevek's considerations of a Soviet "Liftersky", so far as I am aware, the chance of the NK-15 or NK-33 engines getting on new rockets were vanishingly small. Glushko seems to have had it in for the engines. If the Proton rocket fails spectacularly when the Politburo visit to watch the launch (forcing them to run away from the toxic cloud) as OTL, the Soviets will definitely want to replace the Proton. Honestly, with the US program going the direction it is, I think the Soviets would opt for the 11K77 medium-lift vehicle (what became OTL's Zenit-2) and the 11K37 heavy-lift vehicle (which OTL never got off the drawing board). The Soviets were planning to make the family of boosters with re-useable first stages anyway and their designs don't need to be manned the way the US Lifter does. I suspect the Soviets would also look into developing a high-power LH2/LOX upper stage, since the Politburo were feeling inferior to the US in LH2 technology and wanted to catch up.
Without the US building a giant monster of a shuttle, Glushko has no excuse to push for his Mars rocket, and the rest of the Soviet space establishment sans-Barmin (who will want a moon rocket about the size of Energia for the Barmingrad moonbase) will push Glushko to get behind the rockets THEY wanted - which would certainly be equal or smaller than the 11K37 with a LH2/LOX upper stage. As such, I expect Glushko would fight all the harder to get his big rocket engine to make sure he had his page in the history books secured.
I suspect that the main area Soviet ambition will be pushed forward (rather than back) by the changes in the US is that they'll look harder at how to make the Zenit first stages fly-back stages.
fasquardon
The S-IVB IOTL was expensive due to being heavily optimized for performance and then spread over a very short production run, where Titan (the typical point of comparison) was optimized for production. The S-IVC is optimized for production, and thus cheaper than the S-IVB despite a higher propellant capability. As for it being more expensive than Lifter as a fraction of the flight costs of Lifter...the cost listed for Lifter there is for the per-flight turnaround for Lifter, not initial purchase. The cost to turn it around is based on other reusable vehicles in similar flight modes like the X-15 (which saw about 3% of the vehicle's initial purchase cost spent on average after every flight in turnaround costs). Recently, Blue Origins has mentioned some turnaround numbers for New Shepard that indicate that 3% may actually be pessimistic (they've repeatedly mentioned "lows thousands of dollars" spent on per-flight turnaround, which would be in the ballpark of 1% of less of the cost of building it in the first place, making some assumptions.)
Based on the costs of the S-IC (~$85m) in 1971 and the increased costs of a one-off development and build program, we estimated about $220m or so in 1971 (about $1.2b today) as the acquisition cost. We then based per-flight reuse on that estimate and the X-15 and New Shepard experiences. NASA, unlike a private company, can afford to just buy something like that and write it off as startup cost, thus not passing that cost per customer. Still, even if the booster cost was amortized over its expected design life was included, it'd still be cheaper than anything else around, just by a smaller margin.
As for Soviet systems, Groza (whose beginnings are described in Liftoff) has already been laid out. An RD-170-powered, reusable flyback booster (Raskat, which looks a lot like the OTL Russian Baikal proposal), with either one or two pairs lifting a second stage (also RD-170-powered) and optional third stages. Depending on those upper stages, it can launch anywhere from 12 to 55 metric tons. The large end of that, which uses four Raskat boosters lifting what is basically a Zenit-2 stack, is the LV for the Uragan space plane, their equivalent of TTL's Space Shuttle. Other than lifting that, it has potential applications in Glushko's imagining for EOR lunar or Mars missions and heavy space stations. We'll have to see how development and introduction go to see if he can get all that approved...
Do you have any recommended reading for where I could find out about how it was optimized and what the economics of the stage were?
$1.2 billion? OK. That's a pricey piece of kit. Wasn't the price of a whole throw-away Saturn V stack in the same region?
So basically the OTL 11K77 and 11K37 with added flyback capability?
fasquardon
You can do some reading here on the manufacturing processes--note mentions of exacting standards and hand work required. Specifically, look at the "Paleno blocks" and the individually-designated insulation tiles on the interior of the stage. The S-IVC replaces the latter with spray-on insulation as one example of changes for ease of manufacture ITTL. You can find some discussions of estimates for production costs of cheapened S-IVBs and comparisons to Saturn V vintage in reports like this one.
In current dollars? Yeah, it'd be about that. OTOH, with the Saturn stack you'd launch about 127 metric tons to LEO....once. With a Lifter, you can launch about than an order of magnitude greater mass over the life of the vehicle (though you need to buy the upper stages and fairings for those flights, of course). And, of course, the Lifter is a first-generation vehicle.
Similar, because it grows from similar roots, but with differences.
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Was there supposed to be a link inserted into part of this sentence?
What's the manufacture process like for it and how labour intensive is the rocket to set up and launch?
fasquardon
The post is now fixed with this link as was intended.
Well, do you mean initial manufacture of the Raskats, or ongoing manufacture of the Groza cores and upper stages? Anyway, as of yet in the TL, they're not building them, so we'll have to wait and see.
Some back note on S-IVC and cheapened S-IVB production costs.
Like E of Pi say the S-IVB was build for performance not to be cheap !
This include some construction methods apply to S-IVB stage like internal Isocyanate/fiberglas Isolation.
The S-IVC Feature external Isolation probably from Polyurethane Foam
but biggest changes AND cost reduction on S-IVC is its Main Engine the J-2S (S for simplified)
In contrast of complex "plumbing" of J-2 Engine and it subsystems for S-IVB, feature S-IVC tremendous reduction of parts and "plumbing" of J-2S
This reduce the Work and production cost on S-IVC by far as for it predecessor and as bonus get more performance by mass reduction and better engine !
Like E of Pi say the S-IVB was build for performance not to be cheap !
This include some construction methods apply to S-IVB stage like internal Isocyanate/fiberglas Isolation.
The S-IVC Feature external Isolation probably from Polyurethane Foam
but biggest changes AND cost reduction on S-IVC is its Main Engine the J-2S (S for simplified)
In contrast of complex "plumbing" of J-2 Engine and it subsystems for S-IVB, feature S-IVC tremendous reduction of parts and "plumbing" of J-2S
This reduce the Work and production cost on S-IVC by far as for it predecessor and as bonus get more performance by mass reduction and better engine !
Archibald
Banned
A phrase that nails perfectly why this TL is great. Also, the S-IVC / lifting body combination instead of orbiter + external tank. I can only guess the author red Tom Heppenheimer "Space shuttle decision" notably chapter 8
https://www.history.nasa.gov/SP-4221/ch8.htm
Thanks!
I mean both manufacture of the stages and how labour intensive the rocket is to set up on the pad and fire off.
The 11K77 "won" the 1970s competition for what got to be the next-gen Soviet rocket largely because it was designed to be less manpower-intensive.
fasquardon
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Archibald
Banned
Can't help but daydreaming about possible lunar architectures involving ITTL shuttle - lifter+S-IVC.
How about boosting a S-IVC into Earth orbit without any payload, just whatever propellant left in the tanks once it reach orbit.
Then refuel it with LH2 and LOX
or
(if LH2 refueling is too hard) then have the payload being liquid hydrogen by itself and let the mixture ratio do the job 1:7
https://www.google.fr/search?q="LOX+tanker"&ie=utf-8&oe=utf-8&client=firefox-b&gfe_rd=cr&ei=YLq9WK7cJuz-8Ae3kKkQ#q="LOX+tanker"orbit&*
A bit like that except a S-IVC.
https://www.wired.com/2012/08/s-iib-interplanetary-injection-stage-1968/
Surely the lifter could boost enough liquid hydrogen that orbital refueling would be limited to LOX.
According to Wikipedia
An alternative would be to bring back an Apollo CSM (with its escape tower ) instead of the orbiter / lifting body.
Launch CSM + S-IVC + LH2 and LOX refuel in orbit. That way the Lifter can do lunar orbit missions. Of course what is missing is a lunar lander...
The Lifter / S-IVC system might be interesting for manned Mars mission ships build in LEO. There the reusable lifter will be a very useful asset, hopefully lowering cost of the Mars stack.
How about boosting a S-IVC into Earth orbit without any payload, just whatever propellant left in the tanks once it reach orbit.
Then refuel it with LH2 and LOX
or
(if LH2 refueling is too hard) then have the payload being liquid hydrogen by itself and let the mixture ratio do the job 1:7
https://www.google.fr/search?q="LOX+tanker"&ie=utf-8&oe=utf-8&client=firefox-b&gfe_rd=cr&ei=YLq9WK7cJuz-8Ae3kKkQ#q="LOX+tanker"orbit&*
A bit like that except a S-IVC.
https://www.wired.com/2012/08/s-iib-interplanetary-injection-stage-1968/
Surely the lifter could boost enough liquid hydrogen that orbital refueling would be limited to LOX.
According to Wikipedia
An alternative would be to bring back an Apollo CSM (with its escape tower ) instead of the orbiter / lifting body.
Launch CSM + S-IVC + LH2 and LOX refuel in orbit. That way the Lifter can do lunar orbit missions. Of course what is missing is a lunar lander...
The Lifter / S-IVC system might be interesting for manned Mars mission ships build in LEO. There the reusable lifter will be a very useful asset, hopefully lowering cost of the Mars stack.
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Chapter 8: Acceleration
“Houston, Endeavour. Payload separation confirmed. We deliver!”
And they did. Again, and again, and again.
--NASA PAO Educational Film Strip, 1984
With the stress of Max-Q behind it, the Lifter throttled its five F-1B engines back up to full power, spinning their turbopumps up faster and faster to overcome the phenomenal pressures of the combustion chambers and force more oxygen and kerosene in. Flame fronts and shock waves swirled chaotically within the engine, dissipating almost as quickly as they formed when they encountered the specially-shaped baffles along the inner surfaces, releasing their energy before it built up enough to damage the engines.
Though a casual observer on the ground might never realize it, the Lifter was not a rigid body, but one that flexed in response to the strains of flight. The force of her five F-1B engines deformed the thrust structure and the propellant feed lines, changing the rates at which propellant flowed. The vibration of the spinning turbopumps propagated across the stack, exciting every component to motion of its own. Aerodynamic stresses and the automatic compensation by the gimballed rocket engines also exerted an uneven force on the booster, causing it to sway, very subtly, back and forth as it rose.
Within the S-IVC liquid hydrogen tank, a wave began to develop, a rising crest of frothy, boiling cryogenic liquid slowly marching from one side of the tank to the other, altering the vehicle’s center-of-mass as it moved. Unchecked, the wave would have amplified, gathering more and more of the precious fuel into a larger crest, swaying the booster beyond the ability of the gimballed engines to correct. But this was an eventuality for which the engineers on the ground had prepared--the wave crest broke against a perforated baffle, its energy dissipating as noise and much smaller, chaotic waves on the hydrogen’s surface, colliding and amplifying and dissipating one another to nothing, transmitting their mechanical energy into the aluminum tank around them, which, in turn, finally released that energy as an unobservably tiny load of heat, generated by the friction of aluminum plates and struts and bolts against one another, in accordance with the Laws of Thermodynamics.
The Lifter stack accelerated faster and faster, as its mass decreased and as air resistance became negligible. Acceleration piled into velocity, then cascaded into distance as the stack climbed. Through the supersonic regime, into the hypersonic regime, where the heat of air compression began to dominate the airflow around the booster. Her white paint scorched in places as she ascended, succumbing to the intense heat of air unable to get out of the way in time. Still she soldiered on, her computers compensating for every disturbance to her trajectory within milliseconds, taking the intense loads of flight to orbit, and matching them perfectly.
Spacelab was finally completed and launched in 1983, by the Lifter Constitution on the STS-35 mission. The Laboratory Module and Service Module were successfully injected into a 50-degree orbit, chosen as a compromise between coverage of Earth’s surface (for downward-pointing earth observation experiments) and ease-of-access from the low-latitude launch sites favored by NASA and ESA. After separating from its S-IVC stage, the Service Module extended its two broad solar wings and radiator panels, and prepared to receive its first crew. Even before their arrival, however, the space station began beaming back valuable scientific data--geiger counters placed at strategic locations within the spacecraft measured the intensity of cosmic radiation penetrating the outer hull and material samples placed inside the Laboratory Module.
The first crewed mission to Spacelab launched just two weeks later, carrying a crew of six to shake the space station down and perform a variety of scientific experiments during their ten-day stay. The crew checked out the station’s life support system and its ability to provide power to the Orbiter, whose orbital lifetime was ordinarily limited to seven days. Using the Orbiter’s Canadarm, they installed the first External Experiment Pallet on Spacelab’s port side. This first EEP carried a Plasma Diagnostics Package, designed to study the Earth’s ionosphere, and an ESA-developed Instrument Pointing System, designed to improve the tracking capability of Spacelab-mounted observation instruments like solar telescopes and infrared cameras. The PDP would remain on Spacelab for months after the crew returned to Earth, collecting valuable data on the interaction of Earth’s upper atmosphere with ionizing radiation emitted by the Sun. Though this first mission did not demonstrate the full capability of Spacelab, later missions would extend the stay times to two weeks, then three, and finally to 28 days, and carry more advanced instruments and experiment packages.
The first Spacelab mission, STS-36 aboard the Space Shuttle Discovery, also bears the distinction of carrying the first West German astronaut, Ulf Merbold. The Free World’s answer to East German Sigmund Jahn, Merbold was a specialist in Metals Research, and performed experiments on creating ultra-pure semiconducting materials in microgravity. On the thirteenth day of the flight, he also gave a 20-minute interview for the West German public television channel EDF, facilitated by the growing network of TDRS satellites in geostationary orbit. When the interviewer remarked that he’d spent nearly twice as long in space as Jahn had, Merbold cheerfully replied, "mit dem Zweiten ist man besser," "with the second, one is better," a play on the slogan for West Germany’s public television station.
The second Spacelab mission, launched in 1984, would operate for 14 days, during which the crew performed a multitude of experiments in microgravity physics, studying fluid slosh, combustion, and the formation of metallic alloys in microgravity. Spacelab 2 also carried the first Japanese astronaut, Mamoru Mohri, a materials science specialist. The third and fourth Spacelab missions, taking advantage of the longer durations, studied the effects of long-term microgravity exposure on humans and other organisms. Though the deleterious effects of microgravity had been well-known since the Gemini program, determining whether artificial gravity was really necessary remained a top NASA priority. As such, Spacelab 3 and Spacelab 4 tested new exercise regimes and dietary supplements designed to reduce bone and muscle loss in the dangerously low-stress environment of Low Earth Orbit.
The unique experimental opportunities opened by the man-tended Spacelab were demonstrated most dramatically in the interim between Spacelab 4 and Spacelab 5. At the close of the Spacelab 4 mission, the crew left behind an experiment rack developed by Ames Research Center and Johnson Space Center, containing a population of female rats and a supply of food and water. Over the six-month period between Spacelabs 4 and 5, these rats would survive in microgravity, their activities observed by a television camera that beamed signals down to researchers on the ground. Samples of rat urine collected automatically were stored for later analysis, so that hormonal changes in the rats could be studied in greater detail. Though the findings of the experiment matched expectations (the rats displayed a similar decrease in bone and muscle density to humans), the endeavour had proven the utility of the long-term microgravity environment Spacelab offered, and future experiments would take more ambitious steps toward realizing NASA’s goal of a fully-closed life-support system.
While not the massive orbital shipyard, medical research facility, and laboratory for which NASA had hoped in the early 1970s, Spacelab played a vital role in teaching NASA and the European Space Agency how to live and work in space before committing to such a vast project, and helped integrate the ESA and NASDA more closely with NASA’s human spaceflight programs.
Spacelab was not the only program to yield good scientific fruit for NASA. The year 1984 saw the inauguration of Space Launch Complex 2S at Vandenberg Air Force Base. The United States Air Force planned to use Vandenberg for its own classified polar orbit missions, which would require much more payload than the Lifter could provide in a dog-leg trajectory from Cape Canaveral, but this first mission would see the Lifter Intrepid launch the Orbiter Resolution on its second orbital flight. Operating the Lifter at Vandenberg had raised some initial headaches for Air Force engineers--the complexes most suitable for conversion to accommodate the high-thrust RS-IC, SLC-4 and SLC-6, were both simply too difficult to access. Winding roads through the rugged Californian coastal hills meant that the Lifter would have to be raised impractically high off the ground to avoid shearing off its wings. This meant that an entirely new pad would have to be constructed due west of the Vandenberg AFB airfield, adjacent to SLC-2, a Thor-Delta launch pad. The work of building up this new pad delayed the commencement of West Coast Lifter launches until almost five years after the program first took flight, but when the Lifter began operations in California, it hit the ground running.
Resolution would fly from VAFB twice in 1984. Her first flight, STS-48, would be a single-orbit polar test flight, simply to validate the high cross-range capability for which the lifting body design had been chosen in the first place. While a meteorological observation satellite was co-manifested and was separately injected into a polar orbit by the S-IVC after the Shuttle separated, the biggest question on the minds of American officers (and their Soviet counterparts, glued to their radar sets as they watched Resolution sail overhead) was whether the Orbiter could compensate for California shifting to the left about 1,000 miles. Under the command of CDR Robert Overmyer and Pilot Donald Peterson, Resolution reentered the atmosphere over the Arctic Ocean, screamed through the mesosphere at hypersonic speeds over Alaska and British Columbia, and, with a triumphant sonic boom, soared down the length of the California coastline before coming in for a successful landing at Vandenberg.
Work on turning Resolution around for her next flight began immediately. Though mostly a USAF Shuttle, on her next flight, STS-52, Resolution would carry a NASA payload--the Spaceborne Imaging Radar (SIR), a large radar array that filled almost the entire volume of the Orbiter’s small payload bay, and took up so much power and payload mass that no other experiments could be flown with it. SIR allowed NASA to generate very high-resolution radar images of every square meter of land on Earth, from the frigid wastes of northern Greenland to the frigid wastes of the Transantarctic Mountains, and all the mountains, deserts, forests, jungles, prairies, cities, and farms in between. The SIR would fly on Resolution three times between 1984 and 1987, revealing new details about Earth’s landforms hidden by dirt and vegetation accumulated over the centuries. While the radar array would uncover new information about the dynamics of volcanos and discover buried temples and sections of China’s Great Wall, the discovery that generated the most speculation was the announcement by NASA geologist Farouk El-Baz that, by analyzing SIR measurements of the Arabian desert, his team had uncovered two dried-out riverbeds that had once flowed across the peninsula, from Medina to the Persian Gulf. In and of themselves, the two riverbeds would have been of interest only to archaeologists searching for relics of the forerunners of Near Eastern civilization, but their location, the fact that they joined the Tigris and Euphrates in the Persian Gulf, which would have been a marshy river valley in the Neolithic, inspired tabloid newspapers to proclaim to the world that NASA had uncovered the Garden of Eden. To El-Baz’s embarrassment, the think tank Answers in Genesis would claim his work as direct evidence of a Young Earth. Though Resolution’s record of enhancing the scientific literacy of the general population was a bit spotty, the data it recovered with the SIR instrument has been of enormous value to geologists, ecologists, and archaeologists studying worlds hidden away by the relentless sands of time.
The first interplanetary payload launched by Lifter-Centaur was also one of the highest-profile interplanetary missions yet organized by NASA. Since 1968, the Planetary Science Decadal Survey had identified Jupiter as the target of greatest importance, both for understanding the planet itself and its role in the formation of the solar system, and the interest that its magnetosphere and plasma belts held for physicists. NASA therefore began planning for a Jupiter orbital probe even as the Pioneer 10 and 11 spacecraft flew by the king of the planets in 1972 and 1973, and began construction of the probe that would ultimately bear the name “Galileo” even before the Voyager spacecraft launched on their follow-up surveys of the planet. To the chagrin of planetary scientists most concerned with the possibilities of extraterrestrial life, Galileo was too far along in 1979, when Voyagers 1 and 2 sent back evidence of a subsurface ocean on the moon Europa, to be reorganized toward the Galilean moons. Instead, the spacecraft was designed primarily to probe Jupiter itself, dropping a pair of 400-kilogram probes into the depths of the planet’s atmosphere and studying the planet’s magnetosphere and cloud decks. The moons and rings of Jupiter, though important mission objectives, were secondary to the planet itself.
Galileo launched on January 24, 1982, and arrived at Jupiter over 3 years later, approaching the planet over the course of 1985. Separating from its two atmospheric probes in March, the spacecraft finally entered orbit around Jupiter on August 17, 1985, beginning a two-year primary mission around Jupiter. As part of that mission, Galileo acted as a relay for data from its two atmospheric probes, which plunged into two different bands of cloud, one into the equatorial zone, one into the south temperate belt. Descending into the Jovian atmosphere at almost 50 kilometers per second, the probes endured the hottest and highest-acceleration atmospheric entry of any spacecraft before or since. Over the course of their hour-long lifetimes within the Jovian atmosphere, the probes descended over 150 kilometers, observing vastly different environments at each latitude. The equatorial probe descended through a comparatively cloudless region of the Jovian atmosphere, later termed a “hot spot,” with much higher temperatures and lower humidities than the surrounding clouds. Its temperate sister, however, found somewhat slower winds and lower temperatures, and clouds of water, ammonia, and ammonium hydrosulfide. Surprisingly, both probes found that the ratio of nitrogen isotopes in the Jovian atmosphere, the ratio of 15N to 14N, was about 30% lower than that found on Earth, indicating that the nitrogen ratio on Earth was not, as previously thought, the primordial ratio--something had occurred to change the composition of Earth’s nitrogen.
For the next two years, Galileo surveyed the Jovian atmosphere and magnetosphere, and performed observations of the outer Galilean moons (Callisto and Ganymede). The spacecraft also observed the rings of Jupiter and discovered a number of new, smaller moons at low orbits around Jupiter. Following the completion of its prime mission, Galileo began an extended mission, the Galileo Europa Mission, scheduled to last from August 17, 1987 to December 31, 1989. During this mission, Galileo spent more time at lower altitudes, studying the lower Jovian radiation belts and performing close flybys of Europa and Io, the two most geologically active moons in the Jovian system. Since Voyagers 1 and 2 brought them to the attention of the scientific community in 1979, the two moons had been a source of excitement for planetary scientists for different reasons. Io’s widespread volcanic activity prompted questions about how such a small body could produce enough heat to drive the observed eruptions and orogenies, while Europa’s apparently cracked icy surface drove speculation about the possibility of a water-ice ocean underneath the crust, possibly a suitable habitat for non-photosynthetic life. Galileo’s close flybys of each moon raised almost as many questions as they answered, revealing that Io had no functional magnetic field despite being both internally molten and having an iron core, while Europa almost certainly had liquid water under its surface (indeed, the “almost” qualifier dropped out when Galileo fortuitously observed plumes of water jetting from Europa’s southern polar region in February of 1989), though the potential of that water for habitability remained heavily debated.
The smashing success of the Galileo mission, however, was still years off when, in 1981 and 1982, NASA’s planetary science program found itself fighting for its very survival in the face of a Congress whose rallying cry had become “fiscal responsibility.” Though Galileo was too far along by 1981 to cancel (with a launch just months off), NASA’s two other flagship space science missions, the Venus Orbiting Imaging Radar (VOIR) and the American half of the International Solar Polar Mission (ISPM), were not so fortunate. VOIR was intended to follow up on the recently-launched Pioneer Venus Orbiter mission, which had been thrown toward Venus in 1978 by an Atlas-Centaur rocket. VOIR would use a more powerful, more sensitive radar instrument to produce more detailed maps of the Venusian surface, and answer gripping questions about how a planet so similar to Earth in its composition and size could turn out so different by mapping the entire surface. VOIR’s cost, however, exceeded its budget, leading to its cancellation in 1982. Undeterred, NASA’s Solar System Exploration Committee reiterated the importance of the mission in 1983, and secured funding for a somewhat reduced-scale version of the mission, named the Venus Radar Mapper (renamed “Magellan” in 1985). To control costs, Magellan would be built from leftover parts designed for the Voyager and Galileo programs, and would launch on a Lifter-Centaur in 1988.
The American half of ISPM, unlike its inner-solar-system counterpart, would not be resurrected. The Reagan Administration’s FY 1982 budget called for almost a half-billion dollars less for NASA than had been requested, and NASA was forced to perform triage on its own programs. The initial mission plan had called for launches of both the American and European ISPM probes on the same Space Lifter mission in 1983. In 1980, the House Appropriations HUD and Independent Agencies Subcommittee, under the leadership of Representative Edward Boland (D-Mass.) voted to cancel the mission, but the State Department, White House, and other members of Congress reacted strongly enough to reinstate the mission for a 1985 launch. In 1981, however, the White House was under new management, and this time the budget cuts stuck. Though the American ISPM probe had some instruments and capabilities (including a despun instrument array) that the European probe could not match, it was a lower-priority mission for NASA than VOIR, Galileo, or the upcoming Space Telescope.
They could scrape together enough funding to satisfy the Europeans by launching their probe, but not enough to finish the American counterpart. The whole mission, however, was more than the sum of its probes--one ESA official commented that the loss of scientific value was “considerably more than 50%.” The European Space Agency heavily protested the cancellation of the American probe, noting that ISPM had been chosen above many all-European missions in the interest of transatlantic cooperation. The Agency even offered to build a copy of its probe and sell it to NASA for $40 million (though in truth, the loss of tax revenue and the impact of inflation and increased support costs would drive the real cost to $75 million), while the American contractor, TRW, proposed for its part a simplified probe that excised the despun instrument platform for a cost reduction to $120 million. Budgetary constraints carried the day, unfortunately, and on September 11, 1981, the National Academy of Sciences recommended the cancellation of the American half of the ISPM. The apparent unreliability of the Americans for long-term projects left a sour taste in the mouths of ESA’s leadership, one that took years of close cooperation on Spacelab to wash out, but which never entirely went away.
Though hopes that Venus was a lush, earthlike world were dashed on the rocks of infrared astronomy in the 1960s, the planet remained an object of great interest to planetary scientists. Indeed, as the scientific understanding of Earth’s climate and geological history evolved with the discovery of plate tectonics and the first inklings of the modern consensus on climate change, Venus grew even more interesting. How could a world so similar to Earth, just a hair smaller, have turned out so differently? Why is its rotation retrograde? Why is its atmosphere so thick and dry? Why does it lack a magnetic field?
These questions and others motivated the Solar System Exploration Committee at NASA to first recommend the Venus Orbiting Imaging Radar as a top priority in the 1970s, and to fight for it in at least a reduced form after its cancellation. The fruit of their labors was the Magellan probe, a spacecraft constructed mostly from spare parts from the Galileo and Voyager programs. A follow-on to the successful Pioneer Venus Orbiter and Multiprobe mission of 1978, Magellan was to map the surface of Venus in unprecedented detail using its synthetic-aperture radar, improving on the earlier probe’s multi-kilometer resolution by discerning surface features as small as 100 meters across.
On the Magellan program’s shoulders rested not just the livelihoods of Venus researchers, but the fate of an entire planetary science program--Mariner Mark II. Recommended by the Solar System Exploration Committee in 1983, Mariner Mark II was designed to prevent repetition of the cost overruns of the Voyager and Venus Orbiting Imaging Radar programs by standardizing future space probes around common hardware and software solutions, rather than special, single-use components. Though economies of scale were difficult to apply to space probes, which by their nature were produced only in limited numbers, such standardization could at least reduce the development costs of new spacecraft, enabling NASA’s planetary science budget to stretch further. Magellan, though not formally a part of the program, was in many respects a proof-of-concept--its cost was controlled by reusing Galileo and Voyager spare parts. In that respect, it was a success--at the time of launch, the spacecraft had only cost $300 million to develop, which, while a significant overrun from the initially-planned $260 million, was still far below the estimated $500 million cost of Magellan’s predecessor, VOIR. The success of the Magellan program in avoiding cost overruns strengthened the cases for the first two planned Mariner Mark II spacecraft--the Saturn Orbiter/Titan Probe and the Comet Rendezvous/Asteroid Flyby, both planned for the 1990s.
Even as the Lifter system won for itself new laurels, many officers of the United States Air Force came to see value in an independent, redundant space access system in the early 1980s, as the Space Transportation System took over a growing share of the American and global commercial satellite market. As the US transitioned from a liquid-fuel ICBM fleet to an increasingly solid-fueled one, and as the commercial satellite market shifted to the Space Transportation System, the costs of maintaining the Atlas, Titan, Thor, and other rocket families mounted for an ever-shrinking return. Though the Reagan Administration never realized its goal of privatizing the entire American space launch sector, as the manned Orbiter flights remained under the administration of NASA’s Manned Spacecraft Center, the process of developing new launch vehicles and contracting for launches was taken out of NASA’s control and left between the satellite operator and the company that actually built the rockets--just as STC took over operations of the Space Lifter, Convair, Martin-Marietta, and McDonnell-Douglas handled operations of their respective expendable rockets. With the birth of satellite television in the 1970s, went the thinking, would come a new era of commercial competition to develop cost-effective ways to service this new economic sector. Such competition rendered government-developed launch vehicles superfluous or even counterproductive--who would compete with a government-subsidized rocket, after all?
A casualty of this faith in the Invisible Hand, unfortunately, was the so-called “Shuttle Phase II.” Since the compromise that had birthed the Space Lifter architecture in 1972, NASA’s engineers had been predicting that a fully-reusable second stage would supplant the S-IVC and Glider by the 1990s, at the latest, and had pursued design studies and low-level technology development programs to this end. NASA’s Marshall Space Flight Center, in particular, had experimented with small staged-combustion-cycle rocket engines of the type thought necessary to deliver the performance a reusable upper stage would need, while Ames Research Center and Lewis Research Center studied advanced materials and aerodynamic shapes for hypersonic flight. These efforts received a sudden shot in the arm in the late 1970s, when the Carter Administration’s interest in renewable energy led NASA to study multi-thousand-tonne orbital solar power platforms, whose enormous bulk would be uneconomical to fly on the Lifter stack even in the most optimistic scenarios. Orbital solar power platforms would require revolutionary new launch vehicle designs, capable of placing hundreds of tonnes in orbit while reusing the entire vehicle.
Though collectively referred to as “Shuttle Phase II” or simply “Shuttle II,” the proposals generated in the late 1970s differed greatly in the exact approach to full reusability and high payload. Some of the proposals, particularly those put forward by Boeing, proposed a system of two winged stages that returned to runways, essentially an expansion of the then-in-development Lifter stack. Chrysler, for its part, dusted off its SERV proposal from the early 1970s for a single-stage-to-orbit capsule, while Johnson Space Center proposed an enormous, 700-tonne-payload rocket whose stages would splash down in the ocean for recovery. Rockwell’s proposal was arguably the most exotic--a ramjet-powered spaceplane that would fly from a runway to orbit with a 100-tonne payload, 16 times per day. All of these plans seemed to come to nought when the Reagan administration came to power and limited development funding for both the advanced launch vehicles and the orbital solar power platforms that justified them.
Though most of the “Shuttle II” ideas were shelved because their multi-hundred-tonne payload capacities had no discernable market in the 1980s, one proposal--from Martin Marietta, for a two-stage, pop-up vehicle whose first stage would land in an artificial freshwater pond and whose second stage would circumnavigate the Earth before joining it--proved far more adaptable. Martin Marietta, the prime contractor for the Titan II and Titan III launch vehicles, had not managed to gain a stake in the Space Transportation System. As the Shuttle came together and proved, in its first test flights, capable of handling any given commercial, government, or military payload in cislunar space, the company’s executives could see the writing on the wall--unless Martin Marietta came up with an answer to the Shuttle, one that could be sold to NASA at a considerably lower per-launch cost than Titan III, the company faced the total extinction of its space launch division. As such, unlike the other companies to submit design studies for Shuttle II, Martin Marietta continued to develop its proposal on its own dime.
Though the Space Transportation System had only flown a dozen orbital missions when the Reagan administration began its shake-up of American launch contracting, it had almost flawlessly demonstrated the ability to send satellites to geostationary orbit, to launch multiple satellites at once, to approach and observe an uncooperative satellite at close range (demonstrated on the third Orbiter mission), and to launch satellites into a polar orbit from both the West Coast and the East. Experience servicing the RS-IC on the ground indicated that the F-1B engines and aluminum airframe were holding up almost as well as expected--the engines in particular, having been in service in some form for 20 years, had well-understood tolerances, and the flight regime was not more demanding than that for which they had originally been designed. Though time between flights was still greater than NASA had intended, and consequently the cost per-flight was somewhat greater, the STS looked to be well on its way to fulfilling its promise of reduced cost per-kilogram-to-LEO. Of the vast American arsenal of expendable rockets, only Scout seemed safe from obsolescence (its payloads were too small for STS to launch economically, except as a secondary payload).
There was, however, a marginal case where the economics of the STS seemed questionable. The three-ton-to-LEO payload class, served by the Titan IIIB, was also small enough that a dedicated Lifter launch was uneconomical. However, its payloads tended to be sensitive Department of Defense payloads--generally KH-8 reconnaissance satellites and signals intelligence payloads. The United States Air Force was skeptical enough about sharing an architecture with the civilian space program; putting such sensitive payloads together with civil payloads was simply unfeasible. No one wanted to have to give civilian payload technicians the high-level clearance needed to get within feet of USAF payloads.
It would be this market that Martin Marietta tackled with its Reusable Launch Vehicle program, which envisioned a massively scaled-down version of the company’s Shuttle II proposal. Where Shuttle II aimed to put three hundred tonnes in LEO per launch, Martin Marietta’s RLV aimed for the three-to-ten-tonne market. The RLV program operated for approximately 18 months (a clear delineation between it and its successor, CRLV, is difficult to make), during which Martin Marietta changed the recovery method from “freshwater splashdown” to “vertical landing,” as further research concluded that recovery and capital costs would both be considerably lower if the booster’s stages could land on with legs on a concrete pad (a recovery method considerably easier for the small RLV than the gargantuan Shuttle II). Martin Marietta also pioneered the use of “slush hydrogen” propellant, which offered greater performance for a given volume of propellant, though experiments with composite propellant tanks proved, for the moment, unsuccessful. The development of the RLV project would prove extremely useful for Martin Marietta, as other groups were coming to similar conclusions about the capabilities of the Space Transportation System..
In 1983, the United States Air Force, with the blessing of Air Force Undersecretary Pete Aldridge, began a program called “Complementary Reusable Launch Vehicle,” to develop a miniaturized STS optimized for those payloads smaller than 10 tonnes. As its name suggested, it would fly those payloads for which the Space Lifter would be oversized, and having two disimilar reusable launchers would offer a backup to pick up the slack in the event of a fleet-wide stand-down of either system. As Aldridge would say in an interview with Aviation Week & Space Technology in 1988, following his retirement from the USAF, “we never doubted that the Space Transportation System would achieve airliner-like operations. It’s just that we remembered that even airliners have to stand down sometimes.” Secretary of Defense Caspar Weinberger evidently agreed with that sentiment, as in 1984, he approved a space launch strategy that included the development of a CRLV with a payload of 20,000 pounds. Though somewhat smaller than the largest of the Department of Defense’s payloads, the NRO’s new Low Earth Orbit reconnaissance birds, 20,000 lbs was enough to cover the majority of the Department’s geostationary orbit payloads.
The two companies with the biggest stakes in CRLV were Martin Marietta and McDonnell Douglas, the latter of which, like Martin, was watching its stake in the expendable launch vehicle market evaporate. Martin Marietta manufactured the Titan III series of rockets. Derived from the Titan II ICBM, these rockets had been the backbone of the Air Force’s launcher fleet for almost twenty years. McDonnell Douglas, having purchased the Atlas and Centaur production lines from Convair, was also watching most of that investment pass into obsolescence. Though the Centaur would survive as an upper stage for a handful of STS missions beyond Earth orbit, Atlas was on its way out. Both Martin Marietta and McDonnell Douglas understood that, if they wanted to retain any share in the launch market, they had to act now.
McDonnell Douglas’s proposal was a fairly straightforward miniaturization of the STS. Pairing the Centaur Plus developed for STS with a new kerosene-powered flyback first stage, their proposal offered a fairly low development cost (not that the Reagan-era Defense Department wanted for money) and a high degree of confidence by using existing hardware. The greatest innovation in this system, relative to the STS, was in the automated piloting equipment for the first stage--it could return to its launch site without a human pilot.
Under the leadership of Norm Augustine, Vice President of Technical Operations (and soon to be CEO), Martin Marietta proposed a scaled-up version of its RLV project, using its in-house Slush Hydrogen propellant systems, and new high-thrust hydrogen-burning rocket engines. These engines, derived from studies done by Pratt & Whitney and, earlier, Marshall Space Flight Center, would use the staged-combustion cycle, and pick up where the HG-3 project left off. Though more expensive to develop, Martin’s design promised a much lower per-flight cost than McDonnell Douglas’s. As the Strategic Defense Initiative began to take shape, it became clear to the USAF’s leadership that the Department of Defense might soon need a considerably cheaper method of launching payloads to orbit than even the STS could provide. Martin Marietta’s proposal promised more of what they really wanted, and so the company received a Phase A contract in February of 1985 that included a provision for a proof-of-concept vehicle--a vertical-landing demonstrator rocket, dubbed the “Terminal Descent Demonstrator.”
While Space Lifter’s example drove reorganizations and shakeups in the American launch market, Space Shuttle was offering new and exciting options for space utilization. In particular, the Spacelab program also gave NASA engineers an impetus to test an idea that had been kicked around the aerospace industry for over twenty years. Almost as long as there had been orbital rockets, engineers had looked at the upper stages, which entered orbit with the payload, with a nagging sense of guilt that such large pressure vessels were hauled all the way to orbit but then allowed to drop back into the atmosphere to get torn up by hypersonic air resistance. There had therefore been no shortage of suggestions of how to utilize the orbital stages of the rockets--melting them down to recover their aluminum for orbital construction, using them as propellant for electric thrusters and mass drivers, and, of course, returning them to Earth for reuse. But none of these ideas was as enduring as the Wet Workshop idea, which called for the conversion of the stage’s propellant tank into habitable volume. In the Wet Workshop idea, the stage was to vent its residual propellants out into space while a manned spacecraft docked with it, after which a crew would open a hatch in the upper end of the stage to reconfigure it as living space. The idea had a certain romantic appeal--upper stages tended to be enormous compared to the payloads they lifted, after all. Such a Wet Workshop could provide expanded living and working space for a Spacelab crew, allowing the station to gradually expand into the modular space station NASA had always wanted.
The first serious analysis of the Wet Workshop concept came in 1958, when Dr. Krafft Ehricke, working for Convair, noticed that the SM-65 Atlas ICBM could actually boost its core sustainer stage into orbit. He proposed to fit the core stage with a nuclear reactor and a docking port, so that the oxygen tank could be used as living quarters. The Atlas space station would tumble end-over-end to generate artificial gravity, and be serviced at least a dozen times a year by glider flights from Earth. Though the United States did not develop the concept, the basic themes would be revived by Wernher von Braun at Marshall Space Flight Center, who proposed to use the S-II stage of a Saturn V as a massive, 100-tonne space station. MSFC also proposed to use the smaller S-IVB stage on the Saturn IB as a Wet Workshop, and proposed to use the upper stage of a Saturn V in the same manner as a habitat for missions to Venus.
It did not take long for the S-IVC, which was even larger than the S-IVB, to attract the same attention from space station planners. Indeed, since it was much longer than the S-IVB, the stretched stage suggested possibilities for the same tumbling artificial gravity experiments that Ehricke had proposed in 1958, enabling long-term studies of the impacts of lunar and Martian gravity on living organisms. The low cost of the S-IVC (as over a dozen were manufactured each year) and the high launch rate of the Space Lifter hinted at a future where dozens of S-IVCs could be linked up to form octagons and larger shapes, massive wheel-shaped space stations hurtling around the Earth and between the planets. And all it would take to prove the concept would be a single mission, an Orbiter flight that would rendezvous with its own co-orbiting upper stage so the crew could verify the processes needed to outfit the space station. The temptation to test the low-cost promises of the Wet Workshop idea proved too great for even the budget-conscious Reagan Administration to turn down. NASA’s FY 1985 budget included funds for a Wet Workshop demonstration mission, to use a modified S-IVC (fitted with mesh floors and wall brackets for equipment attachment, and a docking collar) and a Docking Module made with surplus parts from the Spacelab project and the Apollo-Soyuz Test Project.
The Wet Workshop would not be the final evolution of the S-IV stage family, however. During the development of the Space Lifter and Orbiter, concerns about Orbiter weight gain led Marshall Space Flight Center to dust off the concept of a two-engine upper stage. In addition to its original purpose of increasing redundancy and guarding against the possibility of an engine-out, the second J-2 would increase the Low Earth Orbit payload of the Space Lifter stack by some seven to eight tons, reducing pressures on the Orbiter’s engineers to cut weight and increasing the amount of payload that any Low Earth Orbit mission could carry. By 1977, the Spacelab program was well underway, and Marshall Space Flight Center also desired the additional payload for missions to the European space station. Again, however, the proposal (dubbed “DEUS,” for Dual Engine Upper Stage) fell on deaf ears. NASA Headquarters pointed to the budget projections for the rest of the 1970s, and at the relative dearth of payloads that would actually require the extra payload (as most Lifter missions were aimed at Geostationary Transfer Orbit, and carried satellites already undersized for the Lifter stack). It was not until 1984 that DEUS rose from the dead and took its place as a fully-funded Space Transportation System component. The Strategic Defense Initiative begun by President Reagan envisioned fleets of high-mass, low-orbiting defensive installations that could deploy high-powered lasers to intercept Soviet ballistic missiles. As time went on, the program’s interests diversified into tactical support (in the form of Dr. Jerry Pournelle’s “Project Thor” concept) and kinetic interception of enemy missiles, but a single theme kept recurring: the need for high-mass payloads in low orbits. By the late 1980s, NASA was moving into plans for a larger follow-on to Spacelab, a permanently-manned outpost in a Low Earth Orbit, and so, for once, the interests of the Department of Defense and those of NASA were fully congruent. The FY1984 budget included an allocation of $100 million for the development and testing of a Dual Engine Upper Stage, for a first flight in 1988.
This more capable and more resilient upper stage wasn’t the only improvement to the Space Transportation System. As the Space Shuttle had built up a flight history, it had become apparent that missions involving external payload deployments were not the limits of the Shuttle system’s applications. The Shuttle had also increasingly attracted attention as a manned science platform and as a cargo transport to Spacelab. For both uses, the Shuttle’s large cargo bay represented a weakness, not a benefit, as the result was a smaller pressurized cockpit. Although several times the size of the Apollo capsule, the Space Shuttle was poorly equipped to handle a crew of more than four or any extended duration, even though it was technically capable of supporting such a crew. Moreover, when supporting a larger crew, the volume available for experiment storage in the cabin was sharply limited.
By adding a pressurized module mounted inside the bay on such science or cargo-focused missions, the Shuttle would be able to make better use of both its existing or future expanded payload capacities. NASA successfully lobbied for funding for the construction of a Multi-Purpose Expansion Module, and a specification was issued in 1983 for construction of two flight-qualified units. Though bids were received from most aerospace firms, there was an expectation within STC’s management that the contract would fall naturally to one of the original STS contractors. The award of the contract to Grumman Aerospace Corporation of Bethpage, New York came as a surprise. As with their proposals for elements of the Space Transportation System, Grumman’s bid was ranked well on cost and technical details, drawing on their Sortie Can studies earlier in the decade. Grumman’s submission was noted for its lightweight structural design and their analysis of how to optimize the design for operational flexibility. Grumman’s STS bids had been hampered by worries over the company’s management and finances. However, many of these had been resolved in the meantime by events such as the delivery of the F14 Tomcat fighter and NASA was less worried on a project that ultimately consisted of little more than delivering an empty metal tube with mounting brackets and wiring trunks which NASA itself would then operate and improve. Demonstrating that NASA was open to encouraging cooperation and that STC would not be allowed to form an effective government monopoly was a side benefit.
Even without the improvements which were planned, the Space Lifter and Space Shuttle forged on with their operations. With Spacelab missions added to the existing manifest of free-flight science and satellite deployment missions, the Space Shuttle flew six times in 1983, during which the Shuttle was used to retrieve the Long Duration Exposed Facility. Adding these to the growing manifest of commercial, scientific, and military satellites riding Space Lifter, the Space Transportation System was boosted above an average of one flight per month. The flight rate only continued to improve in 1984, with eight Shuttle flights and twice as many total Lifter launches, including the program’s fiftieth mission. While improvements to the system and weather shook up the schedule, the Space Transportation pushed ahead in checking off milestones and continued to drive up its flight rate.
And they did. Again, and again, and again.
--NASA PAO Educational Film Strip, 1984
Chapter 8: Acceleration
With the stress of Max-Q behind it, the Lifter throttled its five F-1B engines back up to full power, spinning their turbopumps up faster and faster to overcome the phenomenal pressures of the combustion chambers and force more oxygen and kerosene in. Flame fronts and shock waves swirled chaotically within the engine, dissipating almost as quickly as they formed when they encountered the specially-shaped baffles along the inner surfaces, releasing their energy before it built up enough to damage the engines.
Though a casual observer on the ground might never realize it, the Lifter was not a rigid body, but one that flexed in response to the strains of flight. The force of her five F-1B engines deformed the thrust structure and the propellant feed lines, changing the rates at which propellant flowed. The vibration of the spinning turbopumps propagated across the stack, exciting every component to motion of its own. Aerodynamic stresses and the automatic compensation by the gimballed rocket engines also exerted an uneven force on the booster, causing it to sway, very subtly, back and forth as it rose.
Within the S-IVC liquid hydrogen tank, a wave began to develop, a rising crest of frothy, boiling cryogenic liquid slowly marching from one side of the tank to the other, altering the vehicle’s center-of-mass as it moved. Unchecked, the wave would have amplified, gathering more and more of the precious fuel into a larger crest, swaying the booster beyond the ability of the gimballed engines to correct. But this was an eventuality for which the engineers on the ground had prepared--the wave crest broke against a perforated baffle, its energy dissipating as noise and much smaller, chaotic waves on the hydrogen’s surface, colliding and amplifying and dissipating one another to nothing, transmitting their mechanical energy into the aluminum tank around them, which, in turn, finally released that energy as an unobservably tiny load of heat, generated by the friction of aluminum plates and struts and bolts against one another, in accordance with the Laws of Thermodynamics.
The Lifter stack accelerated faster and faster, as its mass decreased and as air resistance became negligible. Acceleration piled into velocity, then cascaded into distance as the stack climbed. Through the supersonic regime, into the hypersonic regime, where the heat of air compression began to dominate the airflow around the booster. Her white paint scorched in places as she ascended, succumbing to the intense heat of air unable to get out of the way in time. Still she soldiered on, her computers compensating for every disturbance to her trajectory within milliseconds, taking the intense loads of flight to orbit, and matching them perfectly.
Spacelab was finally completed and launched in 1983, by the Lifter Constitution on the STS-35 mission. The Laboratory Module and Service Module were successfully injected into a 50-degree orbit, chosen as a compromise between coverage of Earth’s surface (for downward-pointing earth observation experiments) and ease-of-access from the low-latitude launch sites favored by NASA and ESA. After separating from its S-IVC stage, the Service Module extended its two broad solar wings and radiator panels, and prepared to receive its first crew. Even before their arrival, however, the space station began beaming back valuable scientific data--geiger counters placed at strategic locations within the spacecraft measured the intensity of cosmic radiation penetrating the outer hull and material samples placed inside the Laboratory Module.
The first crewed mission to Spacelab launched just two weeks later, carrying a crew of six to shake the space station down and perform a variety of scientific experiments during their ten-day stay. The crew checked out the station’s life support system and its ability to provide power to the Orbiter, whose orbital lifetime was ordinarily limited to seven days. Using the Orbiter’s Canadarm, they installed the first External Experiment Pallet on Spacelab’s port side. This first EEP carried a Plasma Diagnostics Package, designed to study the Earth’s ionosphere, and an ESA-developed Instrument Pointing System, designed to improve the tracking capability of Spacelab-mounted observation instruments like solar telescopes and infrared cameras. The PDP would remain on Spacelab for months after the crew returned to Earth, collecting valuable data on the interaction of Earth’s upper atmosphere with ionizing radiation emitted by the Sun. Though this first mission did not demonstrate the full capability of Spacelab, later missions would extend the stay times to two weeks, then three, and finally to 28 days, and carry more advanced instruments and experiment packages.
The first Spacelab mission, STS-36 aboard the Space Shuttle Discovery, also bears the distinction of carrying the first West German astronaut, Ulf Merbold. The Free World’s answer to East German Sigmund Jahn, Merbold was a specialist in Metals Research, and performed experiments on creating ultra-pure semiconducting materials in microgravity. On the thirteenth day of the flight, he also gave a 20-minute interview for the West German public television channel EDF, facilitated by the growing network of TDRS satellites in geostationary orbit. When the interviewer remarked that he’d spent nearly twice as long in space as Jahn had, Merbold cheerfully replied, "mit dem Zweiten ist man besser," "with the second, one is better," a play on the slogan for West Germany’s public television station.
The second Spacelab mission, launched in 1984, would operate for 14 days, during which the crew performed a multitude of experiments in microgravity physics, studying fluid slosh, combustion, and the formation of metallic alloys in microgravity. Spacelab 2 also carried the first Japanese astronaut, Mamoru Mohri, a materials science specialist. The third and fourth Spacelab missions, taking advantage of the longer durations, studied the effects of long-term microgravity exposure on humans and other organisms. Though the deleterious effects of microgravity had been well-known since the Gemini program, determining whether artificial gravity was really necessary remained a top NASA priority. As such, Spacelab 3 and Spacelab 4 tested new exercise regimes and dietary supplements designed to reduce bone and muscle loss in the dangerously low-stress environment of Low Earth Orbit.
The unique experimental opportunities opened by the man-tended Spacelab were demonstrated most dramatically in the interim between Spacelab 4 and Spacelab 5. At the close of the Spacelab 4 mission, the crew left behind an experiment rack developed by Ames Research Center and Johnson Space Center, containing a population of female rats and a supply of food and water. Over the six-month period between Spacelabs 4 and 5, these rats would survive in microgravity, their activities observed by a television camera that beamed signals down to researchers on the ground. Samples of rat urine collected automatically were stored for later analysis, so that hormonal changes in the rats could be studied in greater detail. Though the findings of the experiment matched expectations (the rats displayed a similar decrease in bone and muscle density to humans), the endeavour had proven the utility of the long-term microgravity environment Spacelab offered, and future experiments would take more ambitious steps toward realizing NASA’s goal of a fully-closed life-support system.
While not the massive orbital shipyard, medical research facility, and laboratory for which NASA had hoped in the early 1970s, Spacelab played a vital role in teaching NASA and the European Space Agency how to live and work in space before committing to such a vast project, and helped integrate the ESA and NASDA more closely with NASA’s human spaceflight programs.
Spacelab was not the only program to yield good scientific fruit for NASA. The year 1984 saw the inauguration of Space Launch Complex 2S at Vandenberg Air Force Base. The United States Air Force planned to use Vandenberg for its own classified polar orbit missions, which would require much more payload than the Lifter could provide in a dog-leg trajectory from Cape Canaveral, but this first mission would see the Lifter Intrepid launch the Orbiter Resolution on its second orbital flight. Operating the Lifter at Vandenberg had raised some initial headaches for Air Force engineers--the complexes most suitable for conversion to accommodate the high-thrust RS-IC, SLC-4 and SLC-6, were both simply too difficult to access. Winding roads through the rugged Californian coastal hills meant that the Lifter would have to be raised impractically high off the ground to avoid shearing off its wings. This meant that an entirely new pad would have to be constructed due west of the Vandenberg AFB airfield, adjacent to SLC-2, a Thor-Delta launch pad. The work of building up this new pad delayed the commencement of West Coast Lifter launches until almost five years after the program first took flight, but when the Lifter began operations in California, it hit the ground running.
Resolution would fly from VAFB twice in 1984. Her first flight, STS-48, would be a single-orbit polar test flight, simply to validate the high cross-range capability for which the lifting body design had been chosen in the first place. While a meteorological observation satellite was co-manifested and was separately injected into a polar orbit by the S-IVC after the Shuttle separated, the biggest question on the minds of American officers (and their Soviet counterparts, glued to their radar sets as they watched Resolution sail overhead) was whether the Orbiter could compensate for California shifting to the left about 1,000 miles. Under the command of CDR Robert Overmyer and Pilot Donald Peterson, Resolution reentered the atmosphere over the Arctic Ocean, screamed through the mesosphere at hypersonic speeds over Alaska and British Columbia, and, with a triumphant sonic boom, soared down the length of the California coastline before coming in for a successful landing at Vandenberg.
Work on turning Resolution around for her next flight began immediately. Though mostly a USAF Shuttle, on her next flight, STS-52, Resolution would carry a NASA payload--the Spaceborne Imaging Radar (SIR), a large radar array that filled almost the entire volume of the Orbiter’s small payload bay, and took up so much power and payload mass that no other experiments could be flown with it. SIR allowed NASA to generate very high-resolution radar images of every square meter of land on Earth, from the frigid wastes of northern Greenland to the frigid wastes of the Transantarctic Mountains, and all the mountains, deserts, forests, jungles, prairies, cities, and farms in between. The SIR would fly on Resolution three times between 1984 and 1987, revealing new details about Earth’s landforms hidden by dirt and vegetation accumulated over the centuries. While the radar array would uncover new information about the dynamics of volcanos and discover buried temples and sections of China’s Great Wall, the discovery that generated the most speculation was the announcement by NASA geologist Farouk El-Baz that, by analyzing SIR measurements of the Arabian desert, his team had uncovered two dried-out riverbeds that had once flowed across the peninsula, from Medina to the Persian Gulf. In and of themselves, the two riverbeds would have been of interest only to archaeologists searching for relics of the forerunners of Near Eastern civilization, but their location, the fact that they joined the Tigris and Euphrates in the Persian Gulf, which would have been a marshy river valley in the Neolithic, inspired tabloid newspapers to proclaim to the world that NASA had uncovered the Garden of Eden. To El-Baz’s embarrassment, the think tank Answers in Genesis would claim his work as direct evidence of a Young Earth. Though Resolution’s record of enhancing the scientific literacy of the general population was a bit spotty, the data it recovered with the SIR instrument has been of enormous value to geologists, ecologists, and archaeologists studying worlds hidden away by the relentless sands of time.
The first interplanetary payload launched by Lifter-Centaur was also one of the highest-profile interplanetary missions yet organized by NASA. Since 1968, the Planetary Science Decadal Survey had identified Jupiter as the target of greatest importance, both for understanding the planet itself and its role in the formation of the solar system, and the interest that its magnetosphere and plasma belts held for physicists. NASA therefore began planning for a Jupiter orbital probe even as the Pioneer 10 and 11 spacecraft flew by the king of the planets in 1972 and 1973, and began construction of the probe that would ultimately bear the name “Galileo” even before the Voyager spacecraft launched on their follow-up surveys of the planet. To the chagrin of planetary scientists most concerned with the possibilities of extraterrestrial life, Galileo was too far along in 1979, when Voyagers 1 and 2 sent back evidence of a subsurface ocean on the moon Europa, to be reorganized toward the Galilean moons. Instead, the spacecraft was designed primarily to probe Jupiter itself, dropping a pair of 400-kilogram probes into the depths of the planet’s atmosphere and studying the planet’s magnetosphere and cloud decks. The moons and rings of Jupiter, though important mission objectives, were secondary to the planet itself.
Galileo launched on January 24, 1982, and arrived at Jupiter over 3 years later, approaching the planet over the course of 1985. Separating from its two atmospheric probes in March, the spacecraft finally entered orbit around Jupiter on August 17, 1985, beginning a two-year primary mission around Jupiter. As part of that mission, Galileo acted as a relay for data from its two atmospheric probes, which plunged into two different bands of cloud, one into the equatorial zone, one into the south temperate belt. Descending into the Jovian atmosphere at almost 50 kilometers per second, the probes endured the hottest and highest-acceleration atmospheric entry of any spacecraft before or since. Over the course of their hour-long lifetimes within the Jovian atmosphere, the probes descended over 150 kilometers, observing vastly different environments at each latitude. The equatorial probe descended through a comparatively cloudless region of the Jovian atmosphere, later termed a “hot spot,” with much higher temperatures and lower humidities than the surrounding clouds. Its temperate sister, however, found somewhat slower winds and lower temperatures, and clouds of water, ammonia, and ammonium hydrosulfide. Surprisingly, both probes found that the ratio of nitrogen isotopes in the Jovian atmosphere, the ratio of 15N to 14N, was about 30% lower than that found on Earth, indicating that the nitrogen ratio on Earth was not, as previously thought, the primordial ratio--something had occurred to change the composition of Earth’s nitrogen.
For the next two years, Galileo surveyed the Jovian atmosphere and magnetosphere, and performed observations of the outer Galilean moons (Callisto and Ganymede). The spacecraft also observed the rings of Jupiter and discovered a number of new, smaller moons at low orbits around Jupiter. Following the completion of its prime mission, Galileo began an extended mission, the Galileo Europa Mission, scheduled to last from August 17, 1987 to December 31, 1989. During this mission, Galileo spent more time at lower altitudes, studying the lower Jovian radiation belts and performing close flybys of Europa and Io, the two most geologically active moons in the Jovian system. Since Voyagers 1 and 2 brought them to the attention of the scientific community in 1979, the two moons had been a source of excitement for planetary scientists for different reasons. Io’s widespread volcanic activity prompted questions about how such a small body could produce enough heat to drive the observed eruptions and orogenies, while Europa’s apparently cracked icy surface drove speculation about the possibility of a water-ice ocean underneath the crust, possibly a suitable habitat for non-photosynthetic life. Galileo’s close flybys of each moon raised almost as many questions as they answered, revealing that Io had no functional magnetic field despite being both internally molten and having an iron core, while Europa almost certainly had liquid water under its surface (indeed, the “almost” qualifier dropped out when Galileo fortuitously observed plumes of water jetting from Europa’s southern polar region in February of 1989), though the potential of that water for habitability remained heavily debated.
The smashing success of the Galileo mission, however, was still years off when, in 1981 and 1982, NASA’s planetary science program found itself fighting for its very survival in the face of a Congress whose rallying cry had become “fiscal responsibility.” Though Galileo was too far along by 1981 to cancel (with a launch just months off), NASA’s two other flagship space science missions, the Venus Orbiting Imaging Radar (VOIR) and the American half of the International Solar Polar Mission (ISPM), were not so fortunate. VOIR was intended to follow up on the recently-launched Pioneer Venus Orbiter mission, which had been thrown toward Venus in 1978 by an Atlas-Centaur rocket. VOIR would use a more powerful, more sensitive radar instrument to produce more detailed maps of the Venusian surface, and answer gripping questions about how a planet so similar to Earth in its composition and size could turn out so different by mapping the entire surface. VOIR’s cost, however, exceeded its budget, leading to its cancellation in 1982. Undeterred, NASA’s Solar System Exploration Committee reiterated the importance of the mission in 1983, and secured funding for a somewhat reduced-scale version of the mission, named the Venus Radar Mapper (renamed “Magellan” in 1985). To control costs, Magellan would be built from leftover parts designed for the Voyager and Galileo programs, and would launch on a Lifter-Centaur in 1988.
The American half of ISPM, unlike its inner-solar-system counterpart, would not be resurrected. The Reagan Administration’s FY 1982 budget called for almost a half-billion dollars less for NASA than had been requested, and NASA was forced to perform triage on its own programs. The initial mission plan had called for launches of both the American and European ISPM probes on the same Space Lifter mission in 1983. In 1980, the House Appropriations HUD and Independent Agencies Subcommittee, under the leadership of Representative Edward Boland (D-Mass.) voted to cancel the mission, but the State Department, White House, and other members of Congress reacted strongly enough to reinstate the mission for a 1985 launch. In 1981, however, the White House was under new management, and this time the budget cuts stuck. Though the American ISPM probe had some instruments and capabilities (including a despun instrument array) that the European probe could not match, it was a lower-priority mission for NASA than VOIR, Galileo, or the upcoming Space Telescope.
They could scrape together enough funding to satisfy the Europeans by launching their probe, but not enough to finish the American counterpart. The whole mission, however, was more than the sum of its probes--one ESA official commented that the loss of scientific value was “considerably more than 50%.” The European Space Agency heavily protested the cancellation of the American probe, noting that ISPM had been chosen above many all-European missions in the interest of transatlantic cooperation. The Agency even offered to build a copy of its probe and sell it to NASA for $40 million (though in truth, the loss of tax revenue and the impact of inflation and increased support costs would drive the real cost to $75 million), while the American contractor, TRW, proposed for its part a simplified probe that excised the despun instrument platform for a cost reduction to $120 million. Budgetary constraints carried the day, unfortunately, and on September 11, 1981, the National Academy of Sciences recommended the cancellation of the American half of the ISPM. The apparent unreliability of the Americans for long-term projects left a sour taste in the mouths of ESA’s leadership, one that took years of close cooperation on Spacelab to wash out, but which never entirely went away.
Though hopes that Venus was a lush, earthlike world were dashed on the rocks of infrared astronomy in the 1960s, the planet remained an object of great interest to planetary scientists. Indeed, as the scientific understanding of Earth’s climate and geological history evolved with the discovery of plate tectonics and the first inklings of the modern consensus on climate change, Venus grew even more interesting. How could a world so similar to Earth, just a hair smaller, have turned out so differently? Why is its rotation retrograde? Why is its atmosphere so thick and dry? Why does it lack a magnetic field?
These questions and others motivated the Solar System Exploration Committee at NASA to first recommend the Venus Orbiting Imaging Radar as a top priority in the 1970s, and to fight for it in at least a reduced form after its cancellation. The fruit of their labors was the Magellan probe, a spacecraft constructed mostly from spare parts from the Galileo and Voyager programs. A follow-on to the successful Pioneer Venus Orbiter and Multiprobe mission of 1978, Magellan was to map the surface of Venus in unprecedented detail using its synthetic-aperture radar, improving on the earlier probe’s multi-kilometer resolution by discerning surface features as small as 100 meters across.
On the Magellan program’s shoulders rested not just the livelihoods of Venus researchers, but the fate of an entire planetary science program--Mariner Mark II. Recommended by the Solar System Exploration Committee in 1983, Mariner Mark II was designed to prevent repetition of the cost overruns of the Voyager and Venus Orbiting Imaging Radar programs by standardizing future space probes around common hardware and software solutions, rather than special, single-use components. Though economies of scale were difficult to apply to space probes, which by their nature were produced only in limited numbers, such standardization could at least reduce the development costs of new spacecraft, enabling NASA’s planetary science budget to stretch further. Magellan, though not formally a part of the program, was in many respects a proof-of-concept--its cost was controlled by reusing Galileo and Voyager spare parts. In that respect, it was a success--at the time of launch, the spacecraft had only cost $300 million to develop, which, while a significant overrun from the initially-planned $260 million, was still far below the estimated $500 million cost of Magellan’s predecessor, VOIR. The success of the Magellan program in avoiding cost overruns strengthened the cases for the first two planned Mariner Mark II spacecraft--the Saturn Orbiter/Titan Probe and the Comet Rendezvous/Asteroid Flyby, both planned for the 1990s.
Even as the Lifter system won for itself new laurels, many officers of the United States Air Force came to see value in an independent, redundant space access system in the early 1980s, as the Space Transportation System took over a growing share of the American and global commercial satellite market. As the US transitioned from a liquid-fuel ICBM fleet to an increasingly solid-fueled one, and as the commercial satellite market shifted to the Space Transportation System, the costs of maintaining the Atlas, Titan, Thor, and other rocket families mounted for an ever-shrinking return. Though the Reagan Administration never realized its goal of privatizing the entire American space launch sector, as the manned Orbiter flights remained under the administration of NASA’s Manned Spacecraft Center, the process of developing new launch vehicles and contracting for launches was taken out of NASA’s control and left between the satellite operator and the company that actually built the rockets--just as STC took over operations of the Space Lifter, Convair, Martin-Marietta, and McDonnell-Douglas handled operations of their respective expendable rockets. With the birth of satellite television in the 1970s, went the thinking, would come a new era of commercial competition to develop cost-effective ways to service this new economic sector. Such competition rendered government-developed launch vehicles superfluous or even counterproductive--who would compete with a government-subsidized rocket, after all?
A casualty of this faith in the Invisible Hand, unfortunately, was the so-called “Shuttle Phase II.” Since the compromise that had birthed the Space Lifter architecture in 1972, NASA’s engineers had been predicting that a fully-reusable second stage would supplant the S-IVC and Glider by the 1990s, at the latest, and had pursued design studies and low-level technology development programs to this end. NASA’s Marshall Space Flight Center, in particular, had experimented with small staged-combustion-cycle rocket engines of the type thought necessary to deliver the performance a reusable upper stage would need, while Ames Research Center and Lewis Research Center studied advanced materials and aerodynamic shapes for hypersonic flight. These efforts received a sudden shot in the arm in the late 1970s, when the Carter Administration’s interest in renewable energy led NASA to study multi-thousand-tonne orbital solar power platforms, whose enormous bulk would be uneconomical to fly on the Lifter stack even in the most optimistic scenarios. Orbital solar power platforms would require revolutionary new launch vehicle designs, capable of placing hundreds of tonnes in orbit while reusing the entire vehicle.
Though collectively referred to as “Shuttle Phase II” or simply “Shuttle II,” the proposals generated in the late 1970s differed greatly in the exact approach to full reusability and high payload. Some of the proposals, particularly those put forward by Boeing, proposed a system of two winged stages that returned to runways, essentially an expansion of the then-in-development Lifter stack. Chrysler, for its part, dusted off its SERV proposal from the early 1970s for a single-stage-to-orbit capsule, while Johnson Space Center proposed an enormous, 700-tonne-payload rocket whose stages would splash down in the ocean for recovery. Rockwell’s proposal was arguably the most exotic--a ramjet-powered spaceplane that would fly from a runway to orbit with a 100-tonne payload, 16 times per day. All of these plans seemed to come to nought when the Reagan administration came to power and limited development funding for both the advanced launch vehicles and the orbital solar power platforms that justified them.
Though most of the “Shuttle II” ideas were shelved because their multi-hundred-tonne payload capacities had no discernable market in the 1980s, one proposal--from Martin Marietta, for a two-stage, pop-up vehicle whose first stage would land in an artificial freshwater pond and whose second stage would circumnavigate the Earth before joining it--proved far more adaptable. Martin Marietta, the prime contractor for the Titan II and Titan III launch vehicles, had not managed to gain a stake in the Space Transportation System. As the Shuttle came together and proved, in its first test flights, capable of handling any given commercial, government, or military payload in cislunar space, the company’s executives could see the writing on the wall--unless Martin Marietta came up with an answer to the Shuttle, one that could be sold to NASA at a considerably lower per-launch cost than Titan III, the company faced the total extinction of its space launch division. As such, unlike the other companies to submit design studies for Shuttle II, Martin Marietta continued to develop its proposal on its own dime.
Though the Space Transportation System had only flown a dozen orbital missions when the Reagan administration began its shake-up of American launch contracting, it had almost flawlessly demonstrated the ability to send satellites to geostationary orbit, to launch multiple satellites at once, to approach and observe an uncooperative satellite at close range (demonstrated on the third Orbiter mission), and to launch satellites into a polar orbit from both the West Coast and the East. Experience servicing the RS-IC on the ground indicated that the F-1B engines and aluminum airframe were holding up almost as well as expected--the engines in particular, having been in service in some form for 20 years, had well-understood tolerances, and the flight regime was not more demanding than that for which they had originally been designed. Though time between flights was still greater than NASA had intended, and consequently the cost per-flight was somewhat greater, the STS looked to be well on its way to fulfilling its promise of reduced cost per-kilogram-to-LEO. Of the vast American arsenal of expendable rockets, only Scout seemed safe from obsolescence (its payloads were too small for STS to launch economically, except as a secondary payload).
There was, however, a marginal case where the economics of the STS seemed questionable. The three-ton-to-LEO payload class, served by the Titan IIIB, was also small enough that a dedicated Lifter launch was uneconomical. However, its payloads tended to be sensitive Department of Defense payloads--generally KH-8 reconnaissance satellites and signals intelligence payloads. The United States Air Force was skeptical enough about sharing an architecture with the civilian space program; putting such sensitive payloads together with civil payloads was simply unfeasible. No one wanted to have to give civilian payload technicians the high-level clearance needed to get within feet of USAF payloads.
It would be this market that Martin Marietta tackled with its Reusable Launch Vehicle program, which envisioned a massively scaled-down version of the company’s Shuttle II proposal. Where Shuttle II aimed to put three hundred tonnes in LEO per launch, Martin Marietta’s RLV aimed for the three-to-ten-tonne market. The RLV program operated for approximately 18 months (a clear delineation between it and its successor, CRLV, is difficult to make), during which Martin Marietta changed the recovery method from “freshwater splashdown” to “vertical landing,” as further research concluded that recovery and capital costs would both be considerably lower if the booster’s stages could land on with legs on a concrete pad (a recovery method considerably easier for the small RLV than the gargantuan Shuttle II). Martin Marietta also pioneered the use of “slush hydrogen” propellant, which offered greater performance for a given volume of propellant, though experiments with composite propellant tanks proved, for the moment, unsuccessful. The development of the RLV project would prove extremely useful for Martin Marietta, as other groups were coming to similar conclusions about the capabilities of the Space Transportation System..
In 1983, the United States Air Force, with the blessing of Air Force Undersecretary Pete Aldridge, began a program called “Complementary Reusable Launch Vehicle,” to develop a miniaturized STS optimized for those payloads smaller than 10 tonnes. As its name suggested, it would fly those payloads for which the Space Lifter would be oversized, and having two disimilar reusable launchers would offer a backup to pick up the slack in the event of a fleet-wide stand-down of either system. As Aldridge would say in an interview with Aviation Week & Space Technology in 1988, following his retirement from the USAF, “we never doubted that the Space Transportation System would achieve airliner-like operations. It’s just that we remembered that even airliners have to stand down sometimes.” Secretary of Defense Caspar Weinberger evidently agreed with that sentiment, as in 1984, he approved a space launch strategy that included the development of a CRLV with a payload of 20,000 pounds. Though somewhat smaller than the largest of the Department of Defense’s payloads, the NRO’s new Low Earth Orbit reconnaissance birds, 20,000 lbs was enough to cover the majority of the Department’s geostationary orbit payloads.
The two companies with the biggest stakes in CRLV were Martin Marietta and McDonnell Douglas, the latter of which, like Martin, was watching its stake in the expendable launch vehicle market evaporate. Martin Marietta manufactured the Titan III series of rockets. Derived from the Titan II ICBM, these rockets had been the backbone of the Air Force’s launcher fleet for almost twenty years. McDonnell Douglas, having purchased the Atlas and Centaur production lines from Convair, was also watching most of that investment pass into obsolescence. Though the Centaur would survive as an upper stage for a handful of STS missions beyond Earth orbit, Atlas was on its way out. Both Martin Marietta and McDonnell Douglas understood that, if they wanted to retain any share in the launch market, they had to act now.
McDonnell Douglas’s proposal was a fairly straightforward miniaturization of the STS. Pairing the Centaur Plus developed for STS with a new kerosene-powered flyback first stage, their proposal offered a fairly low development cost (not that the Reagan-era Defense Department wanted for money) and a high degree of confidence by using existing hardware. The greatest innovation in this system, relative to the STS, was in the automated piloting equipment for the first stage--it could return to its launch site without a human pilot.
Under the leadership of Norm Augustine, Vice President of Technical Operations (and soon to be CEO), Martin Marietta proposed a scaled-up version of its RLV project, using its in-house Slush Hydrogen propellant systems, and new high-thrust hydrogen-burning rocket engines. These engines, derived from studies done by Pratt & Whitney and, earlier, Marshall Space Flight Center, would use the staged-combustion cycle, and pick up where the HG-3 project left off. Though more expensive to develop, Martin’s design promised a much lower per-flight cost than McDonnell Douglas’s. As the Strategic Defense Initiative began to take shape, it became clear to the USAF’s leadership that the Department of Defense might soon need a considerably cheaper method of launching payloads to orbit than even the STS could provide. Martin Marietta’s proposal promised more of what they really wanted, and so the company received a Phase A contract in February of 1985 that included a provision for a proof-of-concept vehicle--a vertical-landing demonstrator rocket, dubbed the “Terminal Descent Demonstrator.”
While Space Lifter’s example drove reorganizations and shakeups in the American launch market, Space Shuttle was offering new and exciting options for space utilization. In particular, the Spacelab program also gave NASA engineers an impetus to test an idea that had been kicked around the aerospace industry for over twenty years. Almost as long as there had been orbital rockets, engineers had looked at the upper stages, which entered orbit with the payload, with a nagging sense of guilt that such large pressure vessels were hauled all the way to orbit but then allowed to drop back into the atmosphere to get torn up by hypersonic air resistance. There had therefore been no shortage of suggestions of how to utilize the orbital stages of the rockets--melting them down to recover their aluminum for orbital construction, using them as propellant for electric thrusters and mass drivers, and, of course, returning them to Earth for reuse. But none of these ideas was as enduring as the Wet Workshop idea, which called for the conversion of the stage’s propellant tank into habitable volume. In the Wet Workshop idea, the stage was to vent its residual propellants out into space while a manned spacecraft docked with it, after which a crew would open a hatch in the upper end of the stage to reconfigure it as living space. The idea had a certain romantic appeal--upper stages tended to be enormous compared to the payloads they lifted, after all. Such a Wet Workshop could provide expanded living and working space for a Spacelab crew, allowing the station to gradually expand into the modular space station NASA had always wanted.
The first serious analysis of the Wet Workshop concept came in 1958, when Dr. Krafft Ehricke, working for Convair, noticed that the SM-65 Atlas ICBM could actually boost its core sustainer stage into orbit. He proposed to fit the core stage with a nuclear reactor and a docking port, so that the oxygen tank could be used as living quarters. The Atlas space station would tumble end-over-end to generate artificial gravity, and be serviced at least a dozen times a year by glider flights from Earth. Though the United States did not develop the concept, the basic themes would be revived by Wernher von Braun at Marshall Space Flight Center, who proposed to use the S-II stage of a Saturn V as a massive, 100-tonne space station. MSFC also proposed to use the smaller S-IVB stage on the Saturn IB as a Wet Workshop, and proposed to use the upper stage of a Saturn V in the same manner as a habitat for missions to Venus.
It did not take long for the S-IVC, which was even larger than the S-IVB, to attract the same attention from space station planners. Indeed, since it was much longer than the S-IVB, the stretched stage suggested possibilities for the same tumbling artificial gravity experiments that Ehricke had proposed in 1958, enabling long-term studies of the impacts of lunar and Martian gravity on living organisms. The low cost of the S-IVC (as over a dozen were manufactured each year) and the high launch rate of the Space Lifter hinted at a future where dozens of S-IVCs could be linked up to form octagons and larger shapes, massive wheel-shaped space stations hurtling around the Earth and between the planets. And all it would take to prove the concept would be a single mission, an Orbiter flight that would rendezvous with its own co-orbiting upper stage so the crew could verify the processes needed to outfit the space station. The temptation to test the low-cost promises of the Wet Workshop idea proved too great for even the budget-conscious Reagan Administration to turn down. NASA’s FY 1985 budget included funds for a Wet Workshop demonstration mission, to use a modified S-IVC (fitted with mesh floors and wall brackets for equipment attachment, and a docking collar) and a Docking Module made with surplus parts from the Spacelab project and the Apollo-Soyuz Test Project.
The Wet Workshop would not be the final evolution of the S-IV stage family, however. During the development of the Space Lifter and Orbiter, concerns about Orbiter weight gain led Marshall Space Flight Center to dust off the concept of a two-engine upper stage. In addition to its original purpose of increasing redundancy and guarding against the possibility of an engine-out, the second J-2 would increase the Low Earth Orbit payload of the Space Lifter stack by some seven to eight tons, reducing pressures on the Orbiter’s engineers to cut weight and increasing the amount of payload that any Low Earth Orbit mission could carry. By 1977, the Spacelab program was well underway, and Marshall Space Flight Center also desired the additional payload for missions to the European space station. Again, however, the proposal (dubbed “DEUS,” for Dual Engine Upper Stage) fell on deaf ears. NASA Headquarters pointed to the budget projections for the rest of the 1970s, and at the relative dearth of payloads that would actually require the extra payload (as most Lifter missions were aimed at Geostationary Transfer Orbit, and carried satellites already undersized for the Lifter stack). It was not until 1984 that DEUS rose from the dead and took its place as a fully-funded Space Transportation System component. The Strategic Defense Initiative begun by President Reagan envisioned fleets of high-mass, low-orbiting defensive installations that could deploy high-powered lasers to intercept Soviet ballistic missiles. As time went on, the program’s interests diversified into tactical support (in the form of Dr. Jerry Pournelle’s “Project Thor” concept) and kinetic interception of enemy missiles, but a single theme kept recurring: the need for high-mass payloads in low orbits. By the late 1980s, NASA was moving into plans for a larger follow-on to Spacelab, a permanently-manned outpost in a Low Earth Orbit, and so, for once, the interests of the Department of Defense and those of NASA were fully congruent. The FY1984 budget included an allocation of $100 million for the development and testing of a Dual Engine Upper Stage, for a first flight in 1988.
This more capable and more resilient upper stage wasn’t the only improvement to the Space Transportation System. As the Space Shuttle had built up a flight history, it had become apparent that missions involving external payload deployments were not the limits of the Shuttle system’s applications. The Shuttle had also increasingly attracted attention as a manned science platform and as a cargo transport to Spacelab. For both uses, the Shuttle’s large cargo bay represented a weakness, not a benefit, as the result was a smaller pressurized cockpit. Although several times the size of the Apollo capsule, the Space Shuttle was poorly equipped to handle a crew of more than four or any extended duration, even though it was technically capable of supporting such a crew. Moreover, when supporting a larger crew, the volume available for experiment storage in the cabin was sharply limited.
By adding a pressurized module mounted inside the bay on such science or cargo-focused missions, the Shuttle would be able to make better use of both its existing or future expanded payload capacities. NASA successfully lobbied for funding for the construction of a Multi-Purpose Expansion Module, and a specification was issued in 1983 for construction of two flight-qualified units. Though bids were received from most aerospace firms, there was an expectation within STC’s management that the contract would fall naturally to one of the original STS contractors. The award of the contract to Grumman Aerospace Corporation of Bethpage, New York came as a surprise. As with their proposals for elements of the Space Transportation System, Grumman’s bid was ranked well on cost and technical details, drawing on their Sortie Can studies earlier in the decade. Grumman’s submission was noted for its lightweight structural design and their analysis of how to optimize the design for operational flexibility. Grumman’s STS bids had been hampered by worries over the company’s management and finances. However, many of these had been resolved in the meantime by events such as the delivery of the F14 Tomcat fighter and NASA was less worried on a project that ultimately consisted of little more than delivering an empty metal tube with mounting brackets and wiring trunks which NASA itself would then operate and improve. Demonstrating that NASA was open to encouraging cooperation and that STC would not be allowed to form an effective government monopoly was a side benefit.
Even without the improvements which were planned, the Space Lifter and Space Shuttle forged on with their operations. With Spacelab missions added to the existing manifest of free-flight science and satellite deployment missions, the Space Shuttle flew six times in 1983, during which the Shuttle was used to retrieve the Long Duration Exposed Facility. Adding these to the growing manifest of commercial, scientific, and military satellites riding Space Lifter, the Space Transportation System was boosted above an average of one flight per month. The flight rate only continued to improve in 1984, with eight Shuttle flights and twice as many total Lifter launches, including the program’s fiftieth mission. While improvements to the system and weather shook up the schedule, the Space Transportation pushed ahead in checking off milestones and continued to drive up its flight rate.
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EDF you mean certain ZDF Zweites Deutsches Fernsehen (Second German Television)
and Ulf Merbold remark "Das Zweite" will rase some eyebrows in Germany
because in correct german language Merbold has to say "DER Zweite"
but that not first time ZDF get a award for adulterate the German language with bad orthography
better is this ZDF motto from 1980s
Mit dem Zweiten sieht man besser. With the Second one sees better. (wordplay)
Merbold use
Mit dem Zweiten ist man besser. With the Second one is better. (wordplay)
That Martin Marietta goes SpaceX is ultra cool !
would not more logical that General Dynamics built it self of instead McDonnell Douglas ?
and Ulf Merbold remark "Das Zweite" will rase some eyebrows in Germany
because in correct german language Merbold has to say "DER Zweite"
but that not first time ZDF get a award for adulterate the German language with bad orthography
better is this ZDF motto from 1980s
Mit dem Zweiten sieht man besser. With the Second one sees better. (wordplay)
Merbold use
Mit dem Zweiten ist man besser. With the Second one is better. (wordplay)
That Martin Marietta goes SpaceX is ultra cool !
Convair had in 1965 proposed that a Modified Atlas into Recoverable Atlas Booster (RAB) wich also feature a Lifting body as seconds stage or Centaur
would not more logical that General Dynamics built it self of instead McDonnell Douglas ?
Convair had in 1965 proposed that a Modified Atlas into Recoverable Atlas Booster (RAB) wich also feature a Lifting body as seconds stage or Centaur
would not more logical that General Dynamics built it self of instead McDonnell Douglas ?
I do believe I hate you
Where did you get those? (I have the APR copy of the proposal but I've never seen those before)Randy
Thanks a lot! We're all happy you've enjoyed it so far!
Nice catch. That mistake was not intended (neuter vs. masculine nouns always got me in German class), but has been corrected.
They're leaning toward it (and with Norm Augustine at the helm, they're in a good position to innovate hard), but they'll be taking a different approach than SpaceX has IOTL.
The problem with a reusable Atlas-Centaur is that it would be too small to capture the GTO market effectively, even assuming that you could convert the Atlas body to be recoverable without, essentially, building a new LV (and the Atlas balloon tank, which deforms under its own weight without pressurization, would require so much stiffening that you've essentially defeated the purpose of the balloon tank and built a whole new LV--imagine a rocket that starts flopping about under hypersonic air resistance or which deflates after its wheels stop on the runway!). It's something that GD looked at a bit more ITTL than IOTL, but the case for it just didn't close.
Hence, McDonnell-Douglas and Martin-Marietta, whose experience with launch vehicles is more with rigid airframes, have an easier time shifting gears to building rocket-propelled airplanes.
don't hate me, RanulfCI do believe I hate you
The source is San Diego Air & Space Museum they uploaded there entire Photo archive on Flickr
https://www.flickr.com/photos/sdasmarchives/albums
And there Movie Archive is on Youtube
https://www.youtube.com/channel/UC17zw0cjN5v9iRMZ3qxFAkw
here some Treasure from SDASM
