Alternate Space Shuttle Program Architecture

What is your preferred Shuttle architecture?

  • Expendable booster, expendable sustainer, orbiter with only on-orbit motors

    Votes: 1 4.5%
  • Expendable booster, orbiter with sustainer motors and expendable tanks

    Votes: 0 0.0%
  • Expendable booster, fully reusable orbiter with sustainer motors and tanks

    Votes: 1 4.5%
  • Reusable booster, expendable sustainer, orbiter with only on-orbit motors

    Votes: 4 18.2%
  • Reusable booster, orbiter with sustainer motors and expendable tanks

    Votes: 3 13.6%
  • Reusable booster, fully reusable orbiter with sustainer motors and tanks

    Votes: 13 59.1%
  • Something else I would like to discuss below

    Votes: 0 0.0%

  • Total voters
    22
It's early 1970, and you're in charge of issuing the Shuttle Phase B design contracts. These are essentially blocks of money distributed to aerospace companies so they can refine competitive proposals. The Nixon administration has made it clear that there will be no immediate funding for moon bases or huge space stations, so the Shuttle is going to be America's presence in space until the political winds shift somewhere down the road. The only requirement that I am imposing is space for at least four crew and downmass of five tons; essentially, you're going to need a spaceplance somewhat larger than Dream Chaser. The question here is, which architectures get your design contracts?

At this point, it's become quite apparent that the Shuttle launch system will be a two-stage-to-orbit launcher composed of three main parts: the booster, the sustainer, and the orbiter. The booster could be reusable, like many of the fly-back designs that came back in Phase A, recoverable, like the OTL SRBs, or expendable, like some of the Saturn-Shuttle concepts with an expendable S-IC as the booster. Some of the Phase A designs gave the orbiter the engines and fuel tanks to act as its own sustainer, while the OTL design included the sustainer engines but not the fuel tanks in the orbiter. The other conceivable option is to have the sustainer engines and tanks in a separate, expendable stage that would boost the orbiter almost all the way to orbit.

Looking back with the full clarity of 20/20 hindsight, we can see that the OTL Shuttle design was a series of compromises driven by Air Force requirements for high downmass and long cross-range performance for missions the OTL Shuttle never actually got a chance to perform. The objective here is to find the best design for the missions that the shuttle actually flew, so the downmass and cross-range requirements become secondary to other issues. Out of the 131 operational missions that the Shuttle flew, 38 were satellite deployments that could have been conducted by expendable vehicles. The remaining 93 missions were missions that would be considered suitable for the Shuttle's capabilities as a reusable small space station with significant downmass capability. These included 8 missions to repair or retrieve satellites, including 5 to Hubble, while many more satellites were deployed and retrieved during individual missions or during later missions. A total of 37 free-flight research missions, including 19 with Spacelab, were flown, with the Shuttle acting as a temporary space station. Finally, 48 missions were flown to space stations, including 11 Shuttle-Mir flights, 25 ISS assembly flights, and 12 ISS logistics flights (with MPLMs).

An explanation of the answer choices:
1. "Expendable booster, expendable sustainer, orbiter with only on-orbit motors"
This would essentially be a fully expendable rocket with a small spaceplane carried on top as a payload. Possible launch vehicles for the era included the Saturn INT-20 concept, in which case the booster would be an expendable S-IC stage, the sustainer would be an expendable S-IVB stage, and an orbiter of up to 60 tons would be carried as payload. A modern counterpart would be the much smaller Dream Chaser launching on an Ariane 5.
2. "Expendable booster, orbiter with sustainer motors and expendable tanks"
Because I don't think its actually possible to consider rockets that have to be taken back to the factory to be rebuilt after each flight to be reusable, this is essentially the OTL Shuttle. Other vehicles in this category are the Shuttle LRB concepts with LH2/LOX or RP-1/LOX side boosters or the Saturn-Shuttle concept.
3. "Expendable booster, fully reusable orbiter with sustainer motors and tanks"
A number of orbiter concepts that carried both engines and fuel tanks to orbits appeared in both the Phase A and Phase B periods. However, all that I could find also used reusable boosters. An orbiter this big would likely require a booster at least as large as the S-IC.
4. "Reusable booster, expendable sustainer, orbiter with only on-orbit motors"
If I remember correctly, this is the architecture that the Right Side Up TL used, with a fly-back S-IC booster, S-IV sustainer, and a small lifting body orbiter.
5. "Reusable booster, orbiter with sustainer motors and expendable tanks"
The archetypal example of this would be the Saturn-Shuttle with a fly-back S-IC as a booster, which was conceptualized in 1972.
6. "Reusable booster, fully reusable orbiter with sustainer motors and tanks"
Concepts like these made up most of the Phase A and Phase B designs. Faget's MSFC DC-3 is one of the better-known examples. I do not consider this option to be realistic given the budgetary constraints place on NASA at the time.

Note that options 1 and 4, with separate sustainers and orbiters, would be able to fly missions without the orbiter.
 
On Low specification and budget NASA shuttle
i would go for Lifting Body in size of Dream Chaser on Titan IIIM rocket

The Titan IIIM is enlarged Titan IIIC for USAF manned spy sat MOL, canceled in 1968
NASA could take over the Titan IIIM cheap since USAF were using Titan IIIM Core as Titan 34, so just complete the Seven segment booster.
as Lifting Body Martin Marietta build the X-24, who design flow three times as X-23 Prime unmanned suborbital
so X-24 as Bigger orbiter on top of Titan IIIM.

of course Capitol Hill would wonder, "why is Martin Marietta build everything in this program ?"
 
I found this article describing concepts for serial development of Shuttle components, which would mean flying a combination of Shuttle and Saturn components until Shuttle development is completed: https://spaceflighthistory.blogspot.com/2015/11/series-development-launching-space.html

The first option here corresponds to Option 4 in the poll. It's a reusable booster launching an expendable sustainer. The payload and fairing at the front of the S-IVB could be replaced with a small orbital spaceplane.
Shuttle-Saturn.jpg


The second option corresponds to Option 3 in the poll. Here we have an expendable S-IC launching a large orbiter capable of taking itself all the way to orbit.
Saturn-Shuttle.gif
 
The booster is the biggest and thus most expensive (all other things being equal) stage. It also has a far more benign reentry regime, so thermal protection is easier.

So. Right Side Up is the safest way to go.
Hope for money to make a reusable upper stage later.
 
Here my version of Space Shuttle for TL 2001: A Space-Time Odyssey
based on Saturn V hardware, expensive in R&D, but lower flight cost as STS
15071265380_6d7fa7e204_c.jpg
 
Here my version of Space Shuttle for TL 2001: A Space-Time Odyssey
based on Saturn V hardware, expensive in R&D, but lower flight cost as STS
15071265380_6d7fa7e204_c.jpg
The R&D costs were what killed full reusability for the OTL Shuttle. Unless you start by just flying the cargo version you have and then developing the orbiter later, there's no way this thing gets done.
 
The R&D costs were what killed full reusability for the OTL Shuttle. Unless you start by just flying the cargo version you have and then developing the orbiter later, there's no way this thing gets done.

In that TL 2001: A Space-Time Odyssey, the Space Race is hot,
after Soviets landed first on Moon, stars Nixon to trow billions of Dollars into NASA
Result is the Saturn Shuttle
 
If the booster and sustainer can be used without the orbiter, that is a major plus. Now missions that don't need a human presence can be launched without the parasitic mass of people, life support, and reentry equipment. The more versatile the system it, the better. IIRC, there was little economic benefit to reusing the solid rocket booster compared to just jettisoning it, and reusing it resulted in extra mass devoted to the recovery system.

Recovering the sustainer/main engines is probably easier if they are attached to the orbiter. If they are attached to the orbiter, develop a second sustainer, either reusable or one-shot, that can be attached to a system that doesn't need people. That will allow much larger deep space probes to be sent out, resulting in either more delta V for a faster voyage, or more mass for more equipment.
 
I have two proposals:

1.

Number 4 "Right side up" would be my favorite choice. Reusable first stage, downsized seconde S-IV stage steamlined for production cost, maybe winged orbiter (Maybe even staying with an upgraded 4 man Apollo capsule with orbital module would work as well)

2.
I'm not sure, if winged first stage would be feasible with the funds given. Winged orbiter less so.

So let's think a little moment, how to make a better STS (OTL version). First sting I would do ist to create a true STS(ystem). Make the orbiter an optionally manned vehicle. Enlagre the payload bay with a stumper nose and create a Crew module as payload with escape capsules from B-70 Valkyre (this might let survive crew in a Challenger type accident. Without crew compartiment on uncrewed flights this would give the ability to lauch large stocks of sattellites at once (not optimal for commercial, but you get what wou get) or big station modules and such. Payload uncrewed about 35-40 tons. If automated landing was thought complicated, let the orbiter land under control of a chasing plane in the air (the russians got it right at once, while NASA thought to be too complicated). Hope, that a Columbia accident occures on an uncrewed mission.
 
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