I did a thread on this before a while back...anyways, the Buran thread got me thinking on how the OTL Space Shuttle was in many ways a dismal failure which managed merely to keep human spaceflight alive for 30 years. A significant accomplishment, yes, but much less than it was originally sold to do. So, AH.commers, how would you improve the shuttle so that it can come closer to its initial promise? How would you make it an economical and successful space launch system? How would you avoid its flaws?
Ah Challenge: Improve the Shuttle
- Thread starter Workable Goblin
- Start date
Depends. What are our design constraints? Must it still have wings? Full reusability, partial, or just the crew portion? Must we be capable of bringing large amounts of payload down?
Well, the first thing you have to do is a subscale experimental system to test out reentry heat protection.
NASA built all these lovely lifting bodies and never orbited any....
Going an incremental route would have made a lot of sense, too. Trying to do EVERYTHING at once meant that any problem could kill the whole project. (Which was even worse with the SSTO effort!)
Edit: don't go with a shuttle at all. Go with reusable boosters and capsules.
Stephen
Banned
Stick with saturn rockets and stick some parashutes on the lower stages to recover them. lugging a big set of wings and landing gear like the shuttle does is just a waste of weight.
Roton was an interesting idea for a reusable launch vehicle, rotors are at least lighter than wings.
Roton was an interesting idea for a reusable launch vehicle, rotors are at least lighter than wings.
Riain
Banned
Technically, have pressure fed liquid boosters. Or better still have a runway takeoff with the 1st stage using a mix of SR71 and X15 technology to put the 2nd stage up to 60+ miles and mach 6+ for the 2nd stage to get the extra 60+ miles hieght and the extra mach 18 needed for orbit.
But even without changing the Shuttle a bit, launch an empty Skylab B into a high, parking orbit after the ASTP so that when the Shuttle is ready it will have somewhere to shuttle to and from.
But even without changing the Shuttle a bit, launch an empty Skylab B into a high, parking orbit after the ASTP so that when the Shuttle is ready it will have somewhere to shuttle to and from.
Design constraints: You are NASA administrator starting 1969 (replacing Paine). That is pretty much all. Don't expect a lot of support for big programs...
@Stephen: Yeah, but it's harder to ensure damage-less parachute landing (witness the Ares-IX flight) versus a controlled runway landing. Not to mention that you can always use a lifting body.
EDIT: This (while incomplete for several reasons, mostly related to classified information Heppenheimer didn't have access to) is a good resource.
Most important thing: Define a niche. Is the shuttle for getting astronauts somewhere? Is it to deploy satellites? Is the airforce really going to use it?
Big problem with the shuttle was that it tried to be THE space vehicle instead of A space vehicle with a defined mission.
It might also help to be honest about the costs. I remember reading at some point fairly early in the shuttle development cycle that one of the economic studies that supported it had extremely questionable economic assumptions.
Big problem with the shuttle was that it tried to be THE space vehicle instead of A space vehicle with a defined mission.
It might also help to be honest about the costs. I remember reading at some point fairly early in the shuttle development cycle that one of the economic studies that supported it had extremely questionable economic assumptions.
Cook
Banned
Funding approval was based on doing 60 flights per years wasn’t it?
Which is 15 flights per year per bird, a launch every 6 days and turn around time of 3 ½ weeks!
Funding approval was based on doing 60 flights per years wasn’t it?
Which is 15 flights per year per bird, a launch every 6 days and turn around time of 3 ½ weeks!
More or less, yes (the actual NASA baseline was 57 flights/year, and the break-even point (according to the Mathematica analysis) was 39 flights/year. The shuttle is constrained to 24 flights/year by the rate at which Michoud can produce ETs) They wanted to have more than 4 OVs, though, initial plans were for at least 5 (which would mean that turnaround time would only have to be ~6 1/2 weeks for the minimal scenario).
I think a good starting point is to let NASA develop it without USAF/DoD interference. Wasn't that what led to the low angle of attack and the need to bring satellites down from orbit?
Riain
Banned
I thought the USAF demanded big wings for crossrange performance; basically to launch from Vandenburg, release sattelite and land in 1 orbit, by which time Vandenburg had moved east 1500 miles or something. This requirement, and the payload bay size and weight dictated the shuttle's dimensions and therefore fixed operating costs etc.
Design for an ELV, not an RLV. The marginal cost benefits from repeated flights will still exist, but without the issues imposed by an RLV. Design a clustered core like the Atlas V, Delta IV, and Falcon 9, but size the core so a 1 core launch is about 20 tons to orbit total mass in LEO, crew comes out of that). For a three-core launch, that gets you...80 or so? Two of those beats a Saturn, and can lift as much as the most basic SDHLV. Design an big capsule for LEO. Maybe make it able to do BEO as well, I don't know. 4 or 6 person capsule, something like that, plus a SM. Maybe design a pressure fed LRB for the core to match 1xCore flight capacity to missions.
So now, if you fly a few medium satellites or science payloads a year (1x core launches), plus one or two orbital flights (1x core launches), plus a large station component (think a space station built out of a few Skylab-sized modules) or BEO flight (3x core flights) a year, you're talking about 7 launches a year, with maybe 10 cores ordered. That's the sort of area on the cost per launch chart where things take a serious turn for the "not too much" area. And I think without the orbiter reprocessing, that's doable.
So the idea is a common-core ELV starting in the medium range and able to be in the heavy range. Fly it often so economy of scale works for you, and without having a crew on every single flight and a touchy orbiter, there's fewer constraints on usage. Spend the extra money on getting the station flying earlier and going back BEO. Do that and you'll end up with a capable vehicle that will exceed expectations, not merely meet expectations continually revised downwards.
So now, if you fly a few medium satellites or science payloads a year (1x core launches), plus one or two orbital flights (1x core launches), plus a large station component (think a space station built out of a few Skylab-sized modules) or BEO flight (3x core flights) a year, you're talking about 7 launches a year, with maybe 10 cores ordered. That's the sort of area on the cost per launch chart where things take a serious turn for the "not too much" area. And I think without the orbiter reprocessing, that's doable.
So the idea is a common-core ELV starting in the medium range and able to be in the heavy range. Fly it often so economy of scale works for you, and without having a crew on every single flight and a touchy orbiter, there's fewer constraints on usage. Spend the extra money on getting the station flying earlier and going back BEO. Do that and you'll end up with a capable vehicle that will exceed expectations, not merely meet expectations continually revised downwards.
Cook
Banned
I heard much the same; that the Air Force demanded a whole lot of compromises to the design and then decided afterwards that the design wouldn’t suit their needs afterall.
Apollo CSM already worked if those are your requirements. Toward the end, NASA configured one of the CSMs with 5 seats.
http://www.astronautix.com/craft/apouecsm.htm
Hmm...doesn't leave much room for anything but canned apes. If it were to be your BEO return vehicle, you'd also need some kind of hab module even for lunar trips. Still, being able to reuse Apollo program stuff more is nice, saves R&D. And of course, it's already checked out for lunar return. But it'd also make a nice station lifeboat/CTV if you can give it loiter time on orbit...
NothingNow
Banned
Maybe increase the non-propulsion sections of the CSM to Scale up with the Added Demands?
Thande
Donor
The fundamental problem is that the Shuttle programme was polluted with Seventies attitudes: reusable vehicle and recycling SRBs is intrinsically morally superior, for example, even if it costs a hell of a lot more than just building new ones every time.
The shuttle concept to avoid capsule water landings and all the expenses stemming from that wasn't bad, but when you consider all the issues stemming from reusability...
The shuttle concept to avoid capsule water landings and all the expenses stemming from that wasn't bad, but when you consider all the issues stemming from reusability...
NothingNow
Banned
It'd probably be easier to build something like Kliper or Hermes, which gives the basic functionality of the shuttle concept while staying somewhat light and reasonable.
Shouldn't need to for LEO taxi or lifeboat role, the CSM was capable of supporting three men for over a week. That means it should be fine for 5 during the period of ascent, rendezvous and docking with a station, and then later descent and entry. In any BEO operations, I'd plan on it be paired with an orbital module which would provide the extra consumables, delta-v, and volume to deal with the mission proper.