TLIAD: Ares III: To Mars!

Hey, weren't you supposed to be posting another timeline a year ago?
Though I do hope to get back to that (coming soon, Jane's All the World's Hunters of the French Civil War), this isn't related. It is six months old, though, so it doesn't make me look any better. :]

So what's all this then?
A Mars mission in the late 1970s with Apollo-derived technology.

Been there, read the book. Next?
I didn't say OTL Apollo-derived technology; besides, you need an awful lot of divergence for a Mars mission to be plausible. Oh, and we actually flew the thing.

Oh, so "I did it in Kerbal Space Program" is the new watchword for plausibility?
Rest assured all planets, masses, specific impulses, and dates are correct, and the astronaut models would be too if we had our way. We even model underexpansion of exhaust.

Ok fine. But what's with calling a slideshow a TLIAD?
Well, as I said above, even pulling out the stops a late-70s Mars mission isn't that plausible. Besides, we did actually make the thing in a day. A 40-hour day, but no sleep was involved!

And yet you're already past the 40 hour mark.
And that makes this different from other TLIADs?

Right. Well, let's get on with the giant rockets, then.
Music to my ears!


Author's Note:
I had meant to post this since the summer, but I had never quite gotten to it and now it's six months on. It was, however, done in a (40-hour) day. This is a short TL wrapped around a Mars mission that ferram4 and I created. Please ignore any green-skinnedness of the human beings; rest assured all planets, masses, specific impulses, and dates are correct, and the astronaut models would be too if we had our way.
I should NOTE: All these images are links, mostly to 2560x1600 originals (some are smaller, a few larger.)

Welcome to Ares III: Saturn VIII to Mars


Ares is a conjunction-class mission with moderately fast transits (250 days outbound, 220 inbound) and a long (460 day) stay on Mars. The following album recounts the history leading up to Ares III and the mission itself.

The Ares mission plan follows the final Mars plan proposed by Wernher Von Braun. Three stacks will rendezvous in Earth Orbit and will be injected together by their Saturn N nuclear thermal stages into a Trans-Mars trajectory. The three stacks will fly in convoy to Mars, aerobrake separately, and then reunite.

Ares III consists of five launches: three cargo atop Saturn VIII MLV, and two crew using the X-20X DynaSoar crew shuttle. The first launch of Ares III carries the (uncrewed) Flight and Return Vessel, consisting of the Flight Habitation Module, the Earth Return Vehicle (an Apollo-derived medium L/D capsule with capacity of 6), and the Service Module (tasked with Mars Orbit Insertion and Trans-Earth Injection). The second and third launches will loft Mars Surface Stacks, each consisting of a Mars Excursion Module and a Mars Habitat Module, again accompanied by Service Modules (although smaller ones since no TEI burn is needed). Once the three stacks are in orbit and check out, the crew will launch on two X-20Xs and rendezvous with and transfer to the FRV before departure. Once preparations are complete, the stacks will be injected into a Earth-Mars transfer orbit by the Saturn N upper stage still attached to each, and they will fly in convoy to Mars.

SLS A-42

1960: USAF selects the Space Launching System (SLS) as its launcher for DynaSoar and for the SLV-4 requirement. With news of the recent hypergolics catastrophe in Russia implying the United States has more breathing room, the longer development time required for SLS, compared to Titan II derivatives, is viewed as an acceptable risk given its much greater capability.

Excerpt from: Launch Vehicles, A Concise History (NASA Pub.)
SLS A: The smallest of three hydrolox cores in the Space Launching System, a “building block” set of launch vehicles combining hydrolox cores with solid boosters, the SLS A core measures 4.2672m (14ft) in diameter, with a height of 15 meters plus interstage or payload fairing. The fuel mass is 53 tons, with a dry mass of 6 tons. Desgined for the J-2 engine and SLS SRBs, in actual practice due to developmental delays in the J-2 progarm the LR-87-LH2 (a variant of the LR-87 which Aerojet was developing in parallel with the hypergolic LR-87 variant for Titan II) is used instead. While the thrust is lower, it is not much lower than the early figures for the J-2, and no great TWR is necessary for essentially a large upper stage.

Design consists of A core with LR-87LH2 or J-2 engine, with strapon solid boosters. The core is air-lit. The A was designed to be used with either two or four 88 ton solid boosters; however, delays and cost overruns in fabricating these boosters, and promising work being done by United Aircraft on their 120in line of boosters, leads to the light A variant being designated A-18 and featuring eight Minuteman first stages as its boosters; this allows just over seven tons to LEO. The larger A-42 variant, not achieving IOC until 1965, uses two UA1204 four-segment 120inch (3.048m) solid boosters and allows up to ten tons to orbit. Additionally, a Vega or other upper stage may be used for BEO missons.

Gemini 3

June 1965: Gemini 3 begins the second series of US crewed space launches, launching atop an SLS A-18 booster. The Gemini program, originally "Mercury Mark II," will test various orbital capabilities and train astronauts for Apollo.

DynaSoar 3

November 1965: DynaSoar 3, a joint USAF-NASA mission, is the first orbital flight of the X-20 spaceplane, launched atop an SLS A-42 stack. However, a scant few months later another new spacecraft is revealed to the world: in May 1966, the Soviet Union announces the flight of a new spacecraft of their own, Soyuz.




Soyuz 7K-L1 11 ("Zond 7" until splashdown)

December 1968: The Soviets beat the Americans to translunar space with a circumlunar Soyuz 7K-L1 flight launched from an N11 booster. Yuri Gagarin has claimed another first, although the near-fatal Gs on reentry make it his last flight.




AS-806 (Apollo 9)

March 1969: Apollo-Saturn 806 (Apollo 9) is the first crewed mission to orbit the moon, and an all-up test of the Apollo stack, one step away from a moon landing. Tom Stafford is Command Pilot, with John Young as Senior Pilot and Edwin Aldrin as Pilot.

Excerpt from: Launch Vehicles, A Concise History (NASA Pub.)
Saturn VIII: the result of the most extreme design to come out of the direct ascent Saturn studies performed by MSFC, chosen after pressure to design a rocket to put a man on the moon without requiring unproven technologies such as lunar orbit rendezvous or multiple earth orbit rendezvous to build a vehicle.

Design consists of an 8 F-1 1st stage, an 8 J-2 2nd stage, and a modified SLS B upper stage (uses 2 J-2’s). Vehicle is capable of putting 82 tonnes on a trans-lunar trajectory.




N1-L3 to the Moon

August 1969: Alexei Leonov is the first person to set foot on the surface of the moon.




AS-807 (Apollo 10)

October 1969: Apollo 10 lands on the moon. It is flown by the backup crew, the prime crew having shared the flu with each other. Neil Armstrong, a transferree from DynaSoar, is Command Pilot, with Roger B. Chaffee as Senior Pilot and Michael Collins as Pilot. Once again, however, the Americans are playing catchup, though Kennedy's end-of-the-decade challenge is met.




The Ares Program

November 1969: With Apollo landed and Viet Nam at peace, President Lyndon Johnson publicly dedicates the remainder of his term in office to three goals: the fulfillment of FDR's "Fourth Freedom," the freedom from want; an end to racial and sexual discrimination; and seeing the United States set foot on Mars before the end of the next decade. Unspoken is the addendum: before the Soviet Union!


OOC: This concludes the first part (the background, prior to the Mars mission itself). We had to use quite a number of divergences to make a Mars mission even halfway-plausible; cookies if you can spot them all! (Note that one isn't just DynaSoar but the reason DynaSoar survives.)

Part II: The Launch

Ares III-1 Liftoff

October 30, 1979. The first launch of the Ares III mission lifts off, which launches the Flight and Return Vessel (FRV). The LV for the three main launches is the Saturn VIII Modified Launch Vehicle (MLV).

Excerpt from: Launch Vehicles, A Concise History (NASA Pub.)
Saturn VIII MLV: a product of Johnson’s push to reach Mars in a limited timeframe, making use of all available rocket technology and using existing hardware / manufacturing where possible. In practice, this is a Saturn VIII in name only, since the only remaining hardware from the original S-VIII design is the distinctive flared skirt / thrust plate on the first stage, with all other stages being bulked out to meet the nominal tank diameter of the first stage and using completely different engine specifications.

Design consists of an 8 F-1A stretched 1st stage assisted by 8 UA1207 SRMs, a 4 M-1 high-energy, high-thrust 2nd stage, and a 2 AJW3-N130 nuclear transfer stage. Vehicle is capable of 200 tonnes to a trans-martian trajectory.


Ares III-1 first stage

The 8 UA1207 7-segment SRMs provide liftoff thrust to supplement the 8 F-1As and allow a the stretched and bulked-out Saturn VIII MLV to place up to 200 tons on a Trans-Mars trajectory.


Passing Cloud Layer

Notice how the exhaust is under-expanded at the nozzle and billows outward. This is due to the nozzles being optimized for sea level performance; in the lower stratosphere, the air pressure is significantly lower and the exhaust will expand more than the area ratio of the nozzle allows.


Ares III-1 Peak TWR

As the UA1207s gradually burn down, the pressure inside the booster decreases (the entire booster is a thrust chamber); as it decreases, thrust decreases. At this point in the flight, the thrust-to-weight ratio from the combination of the F-1As and the UA1207 SRMs is at its peak due to the large reduction in stack mass.


Zeroth stage separation

UA1207s have burnt out and are staged away. Notice the exhaust plume is still growing as the air pressure reaches a trivial amount.


Ares III-1 Reaches Near-Vacuum

Now nearly in vacuum, the exhaust expands from the F-1As so suddenly that the plume is mostly invisible due how diffuse it is; all that can be seen is some of the superheated soot before it dissipates into the void.


Stage Separation

The 1st stage is separated, and the 2nd stage is ignited. The 4 M-1 engines are the most powerful LH2 + LOX burning engines ever created, and the high thrust and high efficiency of the engines results in this stage providing most (~5 km/s) of the dV to orbit.


PLF Separation

Above most of the atmosphere, the fairings are no longer needed and their fifty ton mass is staged away, revealing the FRV.


Staging Away S-II

Just 600 m/s away from orbital velocity, the 2nd stage burns out and is separated, showing the Saturn N nuclear transfer stage.


Saturn N Ignition

The FRV stack has reached orbit; the Saturn N provides the final kick into orbit, then shuts down. Later it, and the Saturn N stages on the other stacks, will be relit to provide Trans-Mars injection.

Excerpt from: Launch Vehicles, A Concise History (NASA Pub.)
The Saturn N stage is powered by a pair of AJW3-N130 nuclear thermal rockets, the fruit of the partnership formed between Aerojet and Westinghouse during the NERVA program. Running on pure LH2 at 900s, it’s far more efficient than any of the other engine types and cycles available, but large shielding plates need to be added to reduce the effect of stray neutrons coming from either reactor during operation, which could weaken the structure of the stage / payload (through neutron embrittlement), harm the crew, or interfere with the operation of the other reactor (due to neutrons tunneling inside to the core, increasing the reaction rate in unexpected / difficult to predict / unsafe ways).

Ares III-2 Launch

November 5, 1979. Ares III-2 carries a Mars Surface Stack, which contains a Mars Excursion Module (MEM) and Mars Habitation Module (MHM).


Boosters Clear

A nominal ascent, with the dramatic underexpanded effects of a sea level kerosene + LOX rocket engine firing in vacuum.


First Stage Away

1st stage separation and 2nd stage ignition. The Cargo Stack is somewhat heavier than the FRV, so a more aggressive ascent trajectory is chosen.

Burning for Orbit



Ares III-3 Liftoff

November 10, 1979. Ares III-3 carries another Mars Surface Stack into orbit, during the only night launch of the mission. A loose fuel feed line put a temporary hold on the countdown but due to tight scheduling the launch proceeds as soon as all is resolved.


Fire in the Sky

The darkened skies make the exhaust plume even more dramatic.


Looking Backward

A miniature midnight sun lights up the area around the Cape, overawing the light from the cities nearby. Note the tiny little Saturn VIII MLV at the head of the plume.

This really good

Thanks! Glad someone's enjoying it.

I edited the OP with appropriate TLIAD snarkiness; it was rather missing it.

Ares III-4 Lifts Off

November 14, 1979: Astronauts Ferrara, Deraney, and Resnick lift off on a X-20X DynaSoar crew shuttle. The Launch Vehicle is the standard SLS A-42, by now upgraded to its designed-for J-2 engine (a J-2S in this case). The upper stage and maneuvering stage for DynaSoar is the Martin Vega, a cryogenic stage based around an RL-10 engine. Note the large fins on the core and the boosters; this is to force the aerodynamic center below the center of mass of the stack (quite low due to 400 tons of solid fuel).

Excerpt from: Launch Vehicles, A Concise History (NASA Pub.)
X-20X DynaSoar: An evolution of the USAF DynaSoar winged spacecraft, the X-20X has been redesigned for more peaceful requirements. It serves NASA as a crew shuttle, bringing astronauts to and from orbital stations. With an uprated SLS A-42 launcher, DynaSoar can carry four astronauts and 800kg of cargo, and return with 800kg of downmass.

Design consists of a winged hypersonic glider with passive and active (LH2) cooling, a Minuteman third stage solid rocket motor for launch aborts and emergency retrofire, and a Vega-based Service and Mission Module, designed by Martin from their original (circumlunar) Apollo Model 410 service and mission modules. The SMM features an airlock, a docking port, storage space, two extendable solar panels, RCS, a toroidal LH2 and wedge-shaped LOX tank, and an RL-10 engine.


Ares III-4 Booster Separation

The expended UA1204 boosters are staged away, and the auxiliary propulsion thrusters light to ullage the LH2 and liquid oxygen in the A core.


Ares III-4 SLS A Lights

The SLS "A" stage lights. It is a 14ft diameter liquid hydrogen and liquid oxygen stage powered by a J-2 engine; all up mass for the stage is 59 tons, of which 53 are fuel. The J-2 and M-1 engines were developed for SLS, although they were later used in Saturn. Early J-2s had noticeably lower projected thrust than what was actually achieved; for this reason SLS stages generally have a higher thrust-to-weight ratio in practice than they did on the books. However, since they serve as somewhere between a true upper stage and a core stage, this can be quite useful.


Ares III-4 SLS A Detaches

Its propellants expended, the SLS A core is staged away. RCS fires to ullage the Vega.


Ares III-4 Vega Lights

The Vega stage, developed by Martin as a cheaper, safer competitor to Centaur without the latter's balloon tanks and twin RL-10s, is also the maneuvering stage for DynaSoar. Here it ignites for a short time to provide the final push to orbit.


Ares III-4 Orbit Acheived

The Vega stage shuts off, its first burn successful. Ares III-4 has achieved orbit and now will reorient and burn to enter a transfer orbit to rendezvous with the Flight and Return Vessel (FRV). The faired area between the stage and the rear of DynaSoar is pressurized; you can see the airlock from this angle, paired with a dorsal docking port.


Ares III-4 Burns for Rendezvous

The Vega relights to correct Ares III-4's orbit slightly to bring the spacecraft to a direct intercept with the FRV. The docking port, with its clamshell open, can be plainly seen, as well as two ventral solar arrays which are kept extended for low-thrust on-orbit operations.


Coming in to Dock

Ferrara, Deraney, and Resnick reach the FRV and transfer over; once Ares III-4 is cast off, Ares III-5 comes in to dock, bringing Montoya, Merrian, and Seddon. The crew of Ares III proceed to check out all systems on the FRV and the two MSSs.


Ares III-4 Is Go For Descent

After a final lighting of the Vega for retrofire, the stage, service module, and solid abort motor are discarded and the X-20X orients for reentry.


Coming In Hot

Passing by Lake Okeechobee on the right, the X-20X makes S-curves to bleed off speed before turning to come in for a landing at the Cape.


Earth Departure

November 15, 1979: With all systems nominal, the three stacks burn in unison for Mars. The crew settle in for their eight-month journey on the FRV. Following NASA tradition they have named their craft; the FRV is the Enterprise.
During the long flight they will undertake various space-science experiments, attempt to keep up muscle mass, and try as best they can to keep in contact with loved ones at home.


The Cold Times

January 1, 1980: The crew celebrate the dawning of a new year. Before this year is out, they hope to stand on the sands of another world. Just under fifty days into their mission, for the next two hundred days there will only be the void of space. Here Enterprise can be seen with its solar wings fully deployed; avionics and life support require a considerable amount of power, and by the time the craft reach Mars,

Excerpt from: Hardware and Systems of the Ares Program (NASA Pub.)
Flight and Return Vessel:
A long-duration space habitat / spacecraft for the transit to and from Mars, also an offshoot of the Skylab space station proposal. Quite a bit more cramped than the huge Mars Habitation Modules, due to being intended to support twice as many astronauts for a similar period of time.

Design consists of a 7.62m (25ft) diameter, 25m (82ft) length pressure vessel with a supplies for 6 crew for up to 600 days in space (the expected time to return to Earth if an abort is required). A docking port is installed for transferring between the FRV and the MEM for descent / return. A stripped down Apollo capsule with additional (cramped) seating is used as the Earth Return Vehicle for the final reentry. Propulsion is a AJ10-137 engine (note: the versatility of this engine is such that it is used as the ascent stage for Apollo, the ascent stage for the MEM, and as an SPS for the FRV).

Part III: Arrival

Mars In Sight

July 20, 1980: Ares III approaches mars. Only a day out, the crew bring the Cargo Stacks out of hibernation and prepare their own stack as well for Mars capture. The two MSS are commanded to make a small burn so that they will arrive slightly ahead of the FRV.


MSS Aerobrake

July 21, 1980: The first craft of the Ares III mission to reach Mars is the second MSS to launch (via Ares III-3). It "tests the waters" so to speak for the FRV. If the aerobrake proves too dangerous, the Enterprise can make a corrective burn and convert its course into a Mars flyby, then perform a propulsive abort to shorten the return trip as much as possible. However, the aerobrake proceeds apace.


MSS Propulsive Capture

At periapsis, where the burn will have the most effect, the MSS lights its two Lunar Descent Engines, in this case serving as its service propulsion system. Given the effectiveness of the aerobrake, there remains plenty of propellant for rendezvous with the Enterprise and for eventual descent orbit insertion.

FRV Capture Burn

July 22, 1980: After the two MSS have demonstrated that it is safe to do so, Enterprise itself enters Mars's atmosphere to perform a combined aerobrake and propulsive capture. Over a number of passes the FRV, like the two MSS before it, gradually lowers itself into a circular low Mars orbit.


Mars Orbit Rendezvous

With all three stacks in LMO, it is now time to return them together. Given how sorely the Enterprise will require its propellant for Trans-Earth injection later, the two MSS will use their remaining propellant to rendezvous. Once they have done so, the crew of Ares III will give the MEM and MHM another round of checks, and spend a few days observing Mars to choose a landing site (though, given its low elevation and therefore higher atmospheric density, Hellas Planitia is likely to be selected).
Here the first MSS is approaching Enterprise to rendezvous.

Coming in to Dock

The MSS and Enterprise are lined up and ready for final approach and hard lock.

Contact!

The docking port on the nose of the MEM brushes that of the FRV. With some final adjustments and checking of pressure seals, the crew can get to work.


Separation

With the first MSS checked out, it is separated into its two parts and Enterprise's docking port cleared for the second MSS.

Dispersal

July 29, 1980: With the checkouts completed and landing sites surveyed, the crew decide to stick with Hellas Planitia. Therefore the prime crew enter the first MEM, Columbia; it, Enterprise, and the other MEM (Liberty) back away from the two MHMs. The uncrewed MHMs will reenter and land first.

The wonders of Time Warner have left me netless and posting via phone, so this will be--in the fine tradition of TLIADs--delayed a bit.
(I can type, but loading imgur to grab the images from our album? Unlikely.)

Part IV: Landing

Descent Orbit Insertion

MHM 1 fires its engines to insert into a descent orbit calculated to lead to a landing at Hellas Planitia.

Excerpt from: Hardware and Systems of the Ares Program (NASA Pub.)
Mars Habitation Modules: An offshoot of the Skylab space station proposal, using the design of the SLS B / Saturn III stage as a base to create a long-term space habitat. Although original plans called for it to be designed as a wet workshop, the change to Mars made that unfeasible with the available tools, and manufacturing it

Design consists of a 7.62m (25ft) diameter, 30.5m (100ft) length pressure vessel with an airlock, solar panels, supplies for 3 astronauts for 500 days. Includes many parachutes for descent and modified LDE engine and tank structures for final propulsive descent.


Clean for Reentry

The MHM stages away its now-unneeded service propulsion tanks and orients for reentry. Reentry is automated, although with Enterprise overhead manual intervention can be taken and, except when shrouded in plasma, good imagery can be obtained of the descent.


Feeling the Heat

Though Mars's atmosphere is pitiful by Earth standards (let alone Venusian!) it nonetheless requires some level of heat shielding. The MHM is still high enough above the surface that it is well-lit by the sun; as it gets lower, the dawn landing time chosen will make tracking it somewhat difficult (but will yield the maximum daylight for the crew once landed, when much must be done).


Dropping the Shield

Having served its purpose, the heatshield is jettisoned. Due to its very high drag compared to the MHM itself, three solid jettison motors fire to drive it clear of the MHM.


Chutes out!

While the disadvantage of landing at Hellas Planitia is somewhat increased drag and gravity losses on the ascent, its main advantage is that it makes parachutes at least somewhat viable for slowing down. The atmosphere at the base of Hellas has almost double the pressure of the Mars average. The MHM and MEM take advantage of this by mounting parachutes, especially important as they stabilize the descending craft at the correct angle for propulsive landing.


Fully deployed

As the MHM nears the ground, the pressure is finally sufficient to fully open the canopies of the parachutes. The MHM is now orienting fully horizontal, ready for final landing burn.


Touchdown!

The four Lunar Descent Engines fire to brake the final few hundred meters per second of velocity and bring the MHM down to a soft landing. With its partner MHM soon following it, and footage of the area revealing an excellent landing site, it is now time for the first MEM to descend.


Columbia is Go for Landing!

After the successful landing of the two MHMs, it is now judged safe enough to for three of the crew to descend in one of the MEMs. Onboard RCS (fed from the same NTO/Aerozine 50 tanks as the engines) provides the 40m/s retro kick.

Excerpt from: Hardware and Systems of the Ares Program (NASA Pub.)
Mars Excursion Module: A product of a MSFC design study for Mars landers, the MEM is essentially a scaled up Apollo lander combined with an aeroshell and heat shield for the tenuous, but still dangerous, Martian atmosphere. However, since external habitation will be provided, the ascent stage contains only enough room for three (six at overload) crew to strap in; it is far closer to Gemini in this regard than Apollo.

Design consists of 8 adapted Lunar Descent Engines in a descent stage (includes 3 parachutes) and a single AJ10-137 (SPS) powered ascent stage, with solid kick motors to begin the ascent or to perform an abort. Capable of landing 3 astronauts on Mars and then returning them to MEO (300 km x 300 km); using the docking margin, all six could be returned if one MEM fails.


Ice Clouds

Below Columbia can be seen ice clouds in the upper atmosphere of Mars. Also note the ring of solid rocket motors on the detachable heat shield; these are as necessary with the MEM as with the MHM.


Drogues Deployed

Nearing the surface, with the heatshield staged away, the MEM is no longer statically stable. Parachutes not only help decelerate the swiftly-falling Columbia, they also stabilize it in pitch and yaw.


Engines Lit

Only a few kilometers above the surface (which is 8 kilometers below Martian "sea level") the parachutes have slowed the MEM considerably. Now the eight LDEs are lit to handle the final deceleration and provide a soft touchdown


Descending on a Pillar of Flame

Only a few meters above the surface, with the landing gear deployed, Deraney prepares to touch down.


Landed Safely on Another World

"Enterprise, Columbia has landed!"


Hatch Clear!

After letting the dust settle from the landing, it's time to open the hatch.


"We made it."

July 23, 1980: Judith Resnick takes a short step off Columbia's ladder and into history, the first human being to set foot on another planet.

Great stuff!

NathanKell said:

OOC: This concludes the first part (the background, prior to the Mars mission itself). We had to use quite a number of divergences to make a Mars mission even halfway-plausible; cookies if you can spot them all! (Note that one isn't just DynaSoar but the reason DynaSoar survives.)

Click to expand...

My divergence list:

1. Selection of SLS instead of Titan for Dynasoar and subsequent use for Gemini.
2. Dynasoar not cancelled (ridiculous! )
3. The Zond flight the Soviets had lined up for end of 1968 comes off. I guess they didn’t have the Proton failures that scuppered it IOTL?
4. Gagarin didn’t die in March 1968. (I guess this increases the propaganda value of the Zond mission, heaping pressure on the US to respond with a spectacular Mars mission).
5. Apollo selects a direct ascent mission rather than LOR, meaning Saturn here is much closer to OTL’s Nova concept, bigger than Saturn V.
6. N1 is more reliable and available sooner. To be honest, no idea how you fudged that, but it’s nice to see Leonov on the Moon. I guess he must also have been worried about N1’s reliability, as he’s looking a little green...

One thing I wonder about though, the MHM looks awfully exposed balancing on top of its little dinner-plate heat shield. Is this based on an OTL study?

nixonshead, wonderful to see you here!
(And it reminds me I need to catch up on Kolyma's Shadow... )

Great job! You've got about half of them, actually (like I said, we need quite a lot!). The reason for 1 is also the reason for 6 (it's mentioned in the slide for SLS A). For 2, you didn't hit on why DynaSoar wasn't canceled; for more knock-ons from that, see the slide where Johnson proposes Ares (it involves some differing staffing choices, let's put it that way). 4 is spot on, although it's not via Proton (Proton doesn't exist, this was via N11 as the slid mentions)--and the reason is the same reason for 1. You nailed 5, but look at the crew for the first (US) landing. Notice a name out of place? As for 6...hah. (But as for the reason for 6, see my response to 1 above.)

I believe ferram based the MHM on a somewhat later study--but our MHM is essentially an SLS B core, a Mars-surface Skylab if you will, and thus a fair bit sturdier than the usual run of habitat. As I recall, the mass budget didn't allow for a separate aeroshell either. I think in reality they'd have (lightly) faired over the propulsion packages at least, but that's rather hard to do in KSP.

Part V: Mars and Ascent

"We Come In Peace"

The crew plant a flag near the landing site.
Editor's note: please disgregard the oddness of the EVA models. They're human. Really.


Silent Night

As the Martian night falls, the crew of Ares III have been hard at work preparing the MHMs for occupation. By now the second MEM, Liberty, has landed. The crew rests well, for they have many things to do the next day and throughout their fifteen month stay on Mars.

================

The Night Before

October 19, 1981: This will be the crew's last night on Mars. The following day, it will be time to head back to orbit


Liftoff!

October 20, 1981: Both MEMs check out and so the crew will not have to "double up" for the ascent. Columbia's ascent stage fires its solids to kick it free of the descent stage so the main engine (an AJ10-137) can light and carry it to orbit. After over a year on Mars, even the mere double-Earth-G kick of the solid boosters is excruciating, though it lasts only a few seconds.


Say Goodbye

Columbia climbs away from the small base and begins its pitch program. With low gravity and little atmospheric drag, a very shallow ascent is best.


Passing 45 Degrees

Columbia continues pitch program, now passing through the scattered ice clouds.


Circularizing

Reaching Apogee, Columbia burns again to circularize and to put itself on course to rendezvous with Enterprise.

NathanKell said:

nixonshead, wonderful to see you here!
(And it reminds me I need to catch up on Kolyma's Shadow... )

Great job! You've got about half of them, actually (like I said, we need quite a lot!). The reason for 1 is also the reason for 6 (it's mentioned in the slide for SLS A). For 2, you didn't hit on why DynaSoar wasn't canceled; for more knock-ons from that, see the slide where Johnson proposes Ares (it involves some differing staffing choices, let's put it that way). 4 is spot on, although it's not via Proton (Proton doesn't exist, this was via N11 as the slid mentions)--and the reason is the same reason for 1. You nailed 5, but look at the crew for the first (US) landing. Notice a name out of place? As for 6...hah. (But as for the reason for 6, see my response to 1 above.)

I believe ferram based the MHM on a somewhat later study--but our MHM is essentially an SLS B core, a Mars-surface Skylab if you will, and thus a fair bit sturdier than the usual run of habitat. As I recall, the mass budget didn't allow for a separate aeroshell either. I think in reality they'd have (lightly) faired over the propulsion packages at least, but that's rather hard to do in KSP.

Click to expand...

Hmm. Looks like the Nedelin Catastrophie (or a - larger?! - version of it) persuaded the Soviets to avoid hypergolics and focus sooner on the kerolox N1. That explains the earlier, better reliability of N-1 and use of N-11 for the 1968 Zond flyby. It also tipped the scales away from Titan in the US.

So, Johnson's in power in 1969, rather than being forced out of the Democratic nomination and Nixon winning. Could the 1960 election have gone to Nixon, so no McNamara to cancel Dynasoar? But then it would be very unlikely that Nixon would announce an Apollo project. So, how about Kennedy wins in 1960 and survives the assasination attempt. He is then in place to either replace or overrule McNamara on Dynasoar cancellation (although Johnson never did, and he was a comparative space nut). Based on your hint, I'm going to say McNamara was never appointed as SecDef. A different SecDef would help explain both Dynasoar's survival and a better showing in Vietnam (judging by its peaceful status in 1969). A better Vietnam also eases the associated budget pressure, so there's less reason to cancel the Air Force's spaceplane. Anyway, I imagine Kennedy goes on to serve 2 terms, with Johnson succeeding him by winning the 1968 nomination and subsequent election.

Chaffee is on the Moon in October 1969, so either he wasn't in the Apollo-1 fire, or (I suspect more likely) there was no Apollo-1 fire, saving the US some development time for theire bigger Saturn-VIII rocket. This could be storing up trouble for the future, although the more relaxed timescale for the CSM (landing in Oct-69, and with one less Apollo mission preceding - presumably the Apollo-9 LEM Earth orbit test) could mean North American spend more time on quality control and de-bug it without losing lives.

I do wonder what techniques Gemini was meant to address ITTL though. With Apollo using direct ascent, there's no need to practice rendezvous and docking techniques as per OTL. I guess it would just be longer duration flights and maybe EVAs (though space walks are not much like moon walks).

Yep, you got 'em.

The PoD is that the Russians early on acquire data on US hypergolic research (and perhaps, as was sometimes done, incorrect data). That data is given to Chelomei (due to his hiring of Sergei Khrushchev) and Glushko and they quickly attempt a storable missile. It goes very badly indeed, and Sergei is killed in the disaster. In the aftermath, a grief-stricken Nikita is very clear that Glushko will not mess around with these things anymore and instead make exactly the engines Korolev tells him to.

A disaster of that magnitude is impossible for the USSR to entirely cover up, and the USAF gets wind of it; that changes their calculus on Titan vs. SLS, as well as making solids the obvious ICBM route rather than storables. Martin gets a bone thrown to it (Vega, a non-explosive Centaur), as does Aerojet (the LR87-LH2, early engine for the SLS A core).

Mac the Knife indeed lives out his days at Ford. The assassination of Kennedy, however, is not butterflied away, though presumably the exact date is. Johnson can still use the power of martyrdom both for civil rights and for space.

The Apollo I fire, I have come to believe, is far from incidental to the end of the glory days for NASA. Some of NASA's strongest (budgetary) supporters, Muskie for example IIRC, became foes of it after the fire. For a Mars mission to happen, you need there to be money, you need global-political impetus, but you also need to prevent Congressional souring on NASA generally. Thus Doug Chaffee walks on the Moon. I do agree that some disaster is likely; ferram4 and I had considered an Apollo 13-like disaster on an LEO flight or something of the sort (without an LM lifeboat, a translunar 13 would be fatal).
Part of the longer timescale, however, is teething troubles on the Saturn VIII. NAA has a devil of a time getting the common-bulkhead to work, and the first stage has its OTL pogo issues magnified. That gives the Soviets confidence that they might just make it...

Regarding Gemini, duration and EVA, yes, as well as orbital maneuvers. Gemini's service module, ITTL, is rather heavier (as you can see by the LES there's much more margin on an SLS A 18 than on Titan II GLV!) and includes Aerojet's subscale SPS test engine on some flights.

Part VI: Return

Coasting to Rendezvous

Columbia's solar panels are extended during the coast. With a few hundred meters per second of delta v remaining, Columbia has ample reserves to dock with the FRV. Further, this docking will be far simpler than earlier ones, since the ascent stage, nearly dry, masses very little indeed and is quite nimble.


Enterprise In Sight

Approaching the FRV, relative velocity killed by RCS.


Closer...

Ferrara retracts the solar panels and prepares to dock.


Nearly There

In the cone, just a few degrees off.


Lined Up

Ferrara has Columbia lined up perfectly. Now comes the moment of truth: after four hundred and sixty days dormant, in what condition will the crew find the Enterprise? It has been running on auxiliary power (with its solar wings closed up for protection) doing little more than station-keeping, and has been essentially in hibernation, but over a year untouched and unmaintained is a long time for high technology to survive unscathed in far less harsh environments...


Hard Lock

The first three Ares III crew members enter the long-dormant FRV. Remarkably, most systems appear to be in good condition; the few that have suffered damage are either non-critical or can be repaired.


Casting Off Columbia

With the crew of Ferrara, Deraney, and Resnick back aboard, Columbia has served its purpose and is set adrift in medium Mars orbit. Liberty is cleared to launch and rendezvous, carrying Montoya, Merriam, and Seddon.


Homeward Bound

October 25, 1981: With all six crew aboard, and after completing their final checks, Enterprise embarks on the journey home. The FRV's engine is lit for the Trans-Earth injection burn, using up nearly all the remaining propellent. A small reserve remains for any necessary course corrections, as well as the reentry vehicle's RCS.


Speeding away

The Trans-Earth kick nearly doubles the FRV's orbital velocity, at least for a time, and the terrain below speeds by. This will be the crew's last up-close glimpse of Martian terrain, and soon all they will have to gaze upon is a red-orange dot in the sky.

Part VII: Home

Home Sweet Home!

May 30, 1982. The Enterprise returns to Earth’s sphere of influence, making a slight course correction to ensure a safe descent path. The crew has been spending the past weeks working out to prepare their bodies for the return of Earth gravity and for the high reentry g forces.


Speed Record

Enterprise flies high over Africa on its way towards the lower atmosphere. Its trajectory is retrograde with respect to Earth’s rotation to make this a daylight reentry and recovery, and the additional speed that must be burned off is insignificant compared to the 14 km/s of orbital velocity at 180 km.


Last Leg

With everyone crammed into the Earth Return Vehicle, the Enterprise is detached and allowed to fall into the atmosphere, away from the much draggier ERV.


Enterprise Receding



Full Circle

High over where the journey started, nearly 4 years ago.


Getting Warm

The beginning of reentry. The ERV will do a skip reentry to reduce g loads down to a manageable peak of 4.5 gs. This is the equivalent of 11.3 Martian gs, and it’s an unpleasant experience for the crew.


A Valiant Ship

An image captured by an amateur astronomer: the rest of the Enterprise falls into the atmosphere and flares brightly as it begins to disintegrate.


Reentry Interlude

Having hopped back into the upper atmosphere, the reentry flames disappear from the ERV. Still going at nearly orbital velocity, the pod begins to drop back down for another pass.


Once More, Into the Fire!

The final descent results in another 4.4 g peak for the astronauts.


Almost There...

The flames disappear as the velocity drops to 1.2 km/s. With the gs dropping and the flames gone, the crew is nearly home free.


Pop the Chutes!

At ten kilometers, the drogue is deployed; at 6km, the three main chutes deploy.


Three Good Canopies

All three main parachutes deploy fully and the capsule's descent slows to ten meters per second.


Splashdown: Home At Last!

June 3, 1983. The crew of Ferrara, Deraney, Resnick, Montoya, Merriam and Seddon have safely splashed down in the Pacific, the first humans to walk on another planet. Ares III is a resounding success!

And there you have it! It's been vaguely tempting to redo the mission now that the planetary graphics have been improved so much by modders, but it was such a titanic undertaking that that's unlikely.

Hope you enjoyed the ride!