AHC: NASA Wank

[Athelstane]

Prevent Nixon from getting elected. He is the one who started cutting the budget for NASA and ending the rush from the Space Race. Apollo was originally to have 20 missions, until Nixon cut the budget to where only 17 could be launched due to SpaceLab (which was a step back, in my opinion).

The NASA budget was already in freefall before Nixon's election; public support for NASA was already receding rapidly even before Apollo 11 touched down on the Moon.

It will take A LOT more than a different election outcome in 1968 to wank NASA. You're going to need something really dramatic to turn the dynamic around.

 

[Athelstane]

And here's one such dramatic development - the most plausible one:

Most of the Real Push during the 1960's with regards to the Lunar Race was thanks to the perceived lead that the USSR held over the USA at the time with regards to spaceflight. Not an unreasonable position to hold given how many Firsts they'd attained by the mid-60's thanks to the massively over-designed RV ICBM which only needed minor upgrades for their initial growth.

To keep it going, you need the USSR to stay very much in the Race, and this requires a far less toxic relationship between the various competing Bureaus, far better overall management, clear defined goals for them, much-improved quality-assurance and more funding.

With all that, even if they're not First to put a Man on the Moon, they shouldn't be far behind, and that will provide the Drive for NASA to keep on going. At the very least, you can see semi-permanent manned presence on the Lunar Surface alongside LEO Space Stations. Manned Missions to Mars should be looked at more seriously during the 70's-80's, but given the difficulties with getting both there and back, combined with a mindset of taking everything you need with you, I don't really see such an event happening until at least the early-2000's.

Bahamut has hit it on the head (so have others in this thread). Soviet space successes drove the Apollo program in the first place. They must continue for there to be political support for continuing high levels of NASA funding.

That is, unless Neil and Buzz discover alien artifacts or unobtanium on the lunar surface...

 

[Athelstane]

ETS is the most obvious example, written by E of Pi and Workable Goblin.

A significant improvement over OTL's NASA in that different decisions allowed them to leverage more of their Apollo-era hardware which has made getting back to the Moon a simpler task - and thus politically feasible.

We should be clear that...Eyes Turned Skyward is not really a *wank*, but a plausible scenario for NASA choosing a course that makes the best use of (considerably diminished) resources it was going to have access to in the 1970's onward. It may look like a wank compared to our timeline's NASA (an extra Apollo moon landing, permanent space stations from 1978 onward, a return to the Moon by 2000, no interruptions in manned space capability, commercial launch sector and reusable rocket stages coming into being years ahead of our timeline), but it's really not.

 

[brovane]

We should be clear that...Eyes Turned Skyward is not really a *wank*, but a plausible scenario for NASA choosing a course that makes the best use of (considerably diminished) resources it was going to have access to in the 1970's onward. It may look like a wank compared to our timeline's NASA (an extra Apollo moon landing, permanent space stations from 1978 onward, a return to the Moon by 2000, no interruptions in manned space capability, commercial launch sector and reusable rocket stages coming into being years ahead of our timeline), but it's really not.

That is a very good point. "Eyes Turned Skyward" does a good job of operating within the realms of what NASA's historical budget was.

 

[Athelstane]

That is a very good point. "Eyes Turned Skyward" does a good job of operating within the realms of what NASA's historical budget was.

Whereas "Journeys of the Saturn" is more of a wank.

But it's a wank that uses the obvious, most plausible point of departure: a more vigorous and sustained Soviet space program.

 

[brovane]

Whereas "Journeys of the Saturn" is more of a wank.

But it's a wank that uses the obvious, most plausible point of departure: a more vigorous and sustained Soviet space program.

I fully agree. I just don't have the time to go into the researched detail level in Eyes.

"The Journeys of the Saturn"

Really uses two "plausible" points of departure. The sustained Soviet Space Program is a side effect of these.

Kennedy doesn't get killed and somehow keeps the US out of full involvement in Vietnam. I know that Kennedy keeping us out of Vietnam can be argued back and forth. However in my view it is plausible point of departure and not a impossible one.

Alan Shepard doesn't get Meniere disease until June 1969. This results in him commanding Apollo-1 instead of Grissom. Alan Shepard had a much stronger personality than Grissom and has no problem opening his mouth to voice his opinions (He is Al Shepard). Apollo-1 fire never happens and this combined with no Vietnam and Kennedy in office results in the Application Applications program not being cut.

At this point the Apollo program isn't cut and the Soviet's are pushed harder to get manned mission's BEO. This results in essentially a continued space race between the US and the USSR. No country can afford to let their gas off the accelerator so NASA continues with larger budgets than historically.

 

[Athelstane]

I fully agree. I just don't have the time to go into the researched detail level in Eyes.

"The Journeys of the Saturn"

Really uses two "plausible" points of departure. The sustained Soviet Space Program is a side effect of these.

Kennedy doesn't get killed and somehow keeps the US out of full involvement in Vietnam. I know that Kennedy keeping us out of Vietnam can be argued back and forth. However in my view it is plausible point of departure and not a impossible one.

Alan Shepard doesn't get Meniere disease until June 1969. This results in him commanding Apollo-1 instead of Grissom. Alan Shepard had a much stronger personality than Grissom and has no problem opening his mouth to voice his opinions (He is Al Shepard). Apollo-1 fire never happens and this combined with no Vietnam and Kennedy in office results in the Application Applications program not being cut.

At this point the Apollo program isn't cut and the Soviet's are pushed harder to get manned mission's BEO. This results in essentially a continued space race between the US and the USSR. No country can afford to let their gas off the accelerator so NASA continues with larger budgets than historically.

Well, I do think that the Apollo I fire, or some disaster like it, is hard to butterfly away, even by Al Shepard; there were far too many flaws emerging in the architecture, too much of a race with time to discover them all. The result might have been (probably would have been) to avoid the pad fire only to have a disaster up in orbit. But I understand why you did this. As David Portree has pointed out, the Apollo I fire was a big blow to any Apollo follow-on program.

Likewise, I'm less sure that Kennedy could or would have avoided a commitment to Vietnam, though it would have differed in some significant ways, I'm sure. I think your POD here is unlikely, but I will not say it is implausible.

But the biggest driver in your timeline is the proximate, not remote, departures: the emergence of a more vigorous Soviet space program. If the Soviets are committed to a lunar base, no American administration or Congress will find it easy to resist the pressure to match it. Not dumping money down the drain of Indochina will certainly make that easier. Combine these together and you have the makings of a real NASA-wank, even if the motives are not very noble. It was the Soviet space program that made Apollo possible. And it would have been the Soviet space program that would have made possible any effort to build on it with a continued lunar exploration program.

Otherwise, I'm afraid you're gonna need Alien Space Bats for a NASA wank.

 

[Bahamut-255]

Well, I do think that the Apollo I fire, or some disaster like it, is hard to butterfly away, even by Al Shepard; there were far too many flaws emerging in the architecture, too much of a race with time to discover them all. The result might have been (probably would have been) to avoid the pad fire only to have a disaster up in orbit. But I understand why you did this. As David Portree has pointed out, the Apollo I fire was a big blow to any Apollo follow-on program.

I noticed. Took a look and 1968 was the highest budget year NASA had in Constant Dollars, and even that was a reduction on what was originally asked for them by about $500,000,000 in 1968 Dollars. And it's never quite hit that level since.

But the biggest driver in your timeline is the proximate, not remote, departures: the emergence of a more vigorous Soviet space program. If the Soviets are committed to a lunar base, no American administration or Congress will find it easy to resist the pressure to match it. Not dumping money down the drain of Indochina will certainly make that easier. Combine these together and you have the makings of a real NASA-wank, even if the motives are not very noble. It was the Soviet space program that made Apollo possible. And it would have been the Soviet space program that would have made possible any effort to build on it with a continued lunar exploration program.

Indeed. Without a serious competitor to assault the National Pride, it all grinds down to a relative halt.

Otherwise, I'm afraid you're gonna need Alien Space Bats for a NASA wank.

This works too.

 

[Michel Van]

The Shuttle is a hard one. Does the technology exist in the 70's to create a reasonable re-usable space vehicle? Then it also becomes what are you going to re-use?

In my opinion SSTO just doesn't pencil out when you do the math. You really need a leap in material or propulsion technology.

This leaves me with the next best option, TSTO. Certainly by the 90's the technology was their to build a reasonable TSTO vehicle that was fully re-usable. Was the technology their in the 70's to do this? Maybe, but then it becomes how much do you want to spend to get their? In order to really drive down costs and get here.
View attachment 248581

You need a full re-usable vehicle. However can you accept landing some place in-between?

snip

SSTO have the worst Payload/launch mass ratio and most complex R&D and Manufacturing cost

the STS Shuttle a 1/2 stage design had to be cheap in R&D, but became a $10 Billion nightmare for NASA in 1970s
in 1980 it became clear that shuttle was too expensive, do it high crew labor costs to launch it.
a small army was needed to keep the shuttle operational and they needed to be paid wage.

Actual what they needed, it a reusable low cost launcher, that is easy to maintain and is automatic in self check and launch !
here is SpaceX close to reach that goal

like brovane say
it's very difficult to push US Congress for more money for NASA Program
in his "The Journeys of the Saturn" TL he sails elegant by history reefs were NASA run aground
for "2001: a Space-Time Odyssey" it not work well we hit some reefs on way

but two facts important for NASA future

- The Soviets have to bring cosmonaut on moon and planned manned Mars mission.
- The USA-Vietnam War either shorten or averted

in "2001: a Space-Time Odyssey" the Soviets are second on Moon, but it show they can do it and launch Space station in Low orbit
so USA moon landing Triumph is short, the soviet drawn level with USA even past by.
Nixon has to do something so he accept the "Integrated Program Plan" in hope to beat the Soviets in future
even has that price tag of...

 

[Workable Goblin]

Well, I do think that the Apollo I fire, or some disaster like it, is hard to butterfly away, even by Al Shepard; there were far too many flaws emerging in the architecture, too much of a race with time to discover them all. The result might have been (probably would have been) to avoid the pad fire only to have a disaster up in orbit. But I understand why you did this. As David Portree has pointed out, the Apollo I fire was a big blow to any Apollo follow-on program.

I think it's quite possible to eliminate the Apollo 1 fire, it just takes an early PoD. Although Apollo had significant development difficulties by 1967, there's no reason this had to be so; compare to Gemini, which was conceived of after the Apollo Program had started and was developed, operational examples built and flown, and the entire program wrapped up before Apollo flew once. While Gemini was originally "Mercury Mk. II," a Voskhod-like extension of Mercury to two people, it quickly developed into what was, for all practical purposes, an entirely new spacecraft, so it was clearly possible for a functional human spacecraft to be developed and work well on a short time-line, even if North American or Stormy Storms couldn't actually do it in reality. Apollo was a larger and perhaps more complex vehicle than Gemini, but I don't think it was so much larger or more complex as to entirely explain the staggering difference in development time or early vehicle quality.

 

[brovane]

I think it's quite possible to eliminate the Apollo 1 fire, it just takes an early PoD. Although Apollo had significant development difficulties by 1967, there's no reason this had to be so; compare to Gemini, which was conceived of after the Apollo Program had started and was developed, operational examples built and flown, and the entire program wrapped up before Apollo flew once. While Gemini was originally "Mercury Mk. II," a Voskhod-like extension of Mercury to two people, it quickly developed into what was, for all practical purposes, an entirely new spacecraft, so it was clearly possible for a functional human spacecraft to be developed and work well on a short time-line, even if North American or Stormy Storms couldn't actually do it in reality. Apollo was a larger and perhaps more complex vehicle than Gemini, but I don't think it was so much larger or more complex as to entirely explain the staggering difference in development time or early vehicle quality.

As far as spacecraft complexity. If you just compare the actual re-entry part Gemini total Mass 1,982kg, Habitable volume 2.55 m3. The Apollo Command Module total mass 5,560kg, Habitable volume 6.2 m3. When you start comparing the retro module and equipment module of Gemini to the Apollo Service Module their isn't really any comparison, the Apollo Service Module is a beast because of the mission requirements.

I don't think it helped North American that they didn't have the experience that McDonnell had in designing spacecraft. This experience showed when McDonnell designed and built the Gemini. Also from my reading their was a discounting by North American engineers of any experience from Mercury or Gemini when designing and building the Apollo CM. Their response was Apollo wasn't Mercury or Gemini.

 

[Workable Goblin]

As far as spacecraft complexity. If you just compare the actual re-entry part Gemini total Mass 1,982kg, Habitable volume 2.55 m3. The Apollo Command Module total mass 5,560kg, Habitable volume 6.2 m3. When you start comparing the retro module and equipment module of Gemini to the Apollo Service Module their isn't really any comparison, the Apollo Service Module is a beast because of the mission requirements.

Well, yes, but those are size differences, not complexity differences; an example of a complexity difference would be if Apollo had a more powerful computer on board than Gemini, or other more sophisticated support equipment. Merely making a bigger spacecraft isn't the same thing as making a more complicated spacecraft (or, to put it a different way, the HL-20 is clearly a more complex and sophisticated spacecraft than the CSM, despite being similar in dry mass). I've heard it said that Gemini, due to being designed later, was actually more technically sophisticated and complex than Apollo, with more advanced technology on board, but I don't know how true that is.

In any case, as I said Gemini was developed very much faster than Apollo, so that it seems improbable that Apollo could not have been developed to be launched safely by early 1967, with an appropriate PoD. Oddly, McDonnell's Apollo proposal was ranked lowest of the competitors, so it might be hard to simply select them instead, but it could probably be done.

 

[brovane]

Well, I do think that the Apollo I fire, or some disaster like it, is hard to butterfly away, even by Al Shepard; there were far too many flaws emerging in the architecture, too much of a race with time to discover them all. The result might have been (probably would have been) to avoid the pad fire only to have a disaster up in orbit. But I understand why you did this. As

David Portree has pointed out, the Apollo I fire was a big blow to any Apollo follow-on program.

For me with Apollo-1 I am still trying to figure out what they were racing in 1966-1967. The Block 1 CMS was never intended to go the Moon. It doesn't matter how hard you push things if the Lunar Module isn't ready. There is really no reason to be pushing this hard if other critical parts of the program are not ready. If you just change out the hatch to an outward opening hatch, the astronauts will probably live from a pad fire. How I dealt with it was to just have the astronauts raise their hand and say enough is enough we need to slow things down. Something I heard from John Young in an interview sparked this idea. Young was talking to Grissom about a month before the fire and they were talking about how terrible the wiring was in the Command Module. Young told Grissom that he should say something about the issue with the Command Module. Grissom told Young that he couldn't say anything or they will fire me. That kind of struck me, that Grissom after his Mercury capsule sinking was still so afraid of shaking things up a bit. However if you substitute Al Shepard he will have no problem not only shaking the tree but taking a chain saw to it if necessary. This is the man that muscled himself into the Apollo flight rotation as a prime crew commander with no previous backup crew experience. Not saying it is perfect but it certainly isn't implausible.

Likewise, I'm less sure that Kennedy could or would have avoided a commitment to Vietnam, though it would have differed in some significant ways, I'm sure. I think your POD here is unlikely, but I will not say it is implausible.

I just sailed right by that reef. I just don't know enough about the politics of that era to make a good argument either way. Avoiding Vietnam was an easy way to get NASA more money so I took the easy way out so I could write more about rockets.

But the biggest driver in your timeline is the proximate, not remote, departures: the emergence of a more vigorous Soviet space program. If the Soviets are committed to a lunar base, no American administration or Congress will find it easy to resist the pressure to match it. Not dumping money down the drain of Indochina will certainly make that easier. Combine these together and you have the makings of a real NASA-wank, even if the motives are not very noble. It was the Soviet space program that made Apollo possible. And it would have been the Soviet space program that would have made possible any effort to build on it with a continued lunar exploration program.

As you say the Soviet space program has become the biggest driver of NASA. Neither side can afford to blink in the space race.

Otherwise, I'm afraid you're gonna need Alien Space Bats for a NASA wank.

I agree, no Alien Space Bats in my story.

 

[Athelstane]

Apollo was a larger and perhaps more complex vehicle than Gemini, but I don't think it was so much larger or more complex as to entirely explain the staggering difference in development time or early vehicle quality.

Not to defend North American's conduct - it was a questionable decision to give them the CSM bid - but the problem wasn't so much the greater complexity of systems (they were more complex, but not so much as some might think), as it was the problem of the culture - not just at North American, but at NASA itself.

That culture had not resulted in disaster on Gemini, but was becoming a problem with Apollo. (How long, for example, were they going to get away with a pure oxygen environment? That was NASA's decision, not North American's.)

There's a paragraph in Murray and Cox's book (p. 160) that brought this home to me:

A senior ASPO engineer once talked about the personal loss the fire represented to him—asHouston’s project officer for the LEM, he had gotten to know Grissom and White well—but, still,“from an overall standpoint of the program, it might have been one of the best things that could have happened.” It is a tough judgment, he recognized, but “I think we got too complacent in the manned program... The fire really woke people up.” Another engineer thought that the fire gave the Apollo Program some time it was unwilling to give itself; “The Apollo design had progressed to a point where a lot of things were put up on the shelf as being the kind of thing—’Well, let’s not worry about that right now, we’ll pick it up later.’ “He said it wasn’t so much that Apollo 1 would have been dangerous if they’d flown it, but rather that “once the fire occurred, the night schedule came to a screeching halt and everybody stopped and took stock.” People then had the time to go back and work in a less pressured fashion on “all of these things that everyone had in their back pocket that they should haveworked on, and hadn’t had a chance to.”

And because the culture at NASA was developing in this way, I think that some kind of disaster was likely to happen, given the same premises. Al Shepard might have raised a greater fuss than Gus Grissom. But I doubt that he could have turned the culture, the mindset around at Apollo.

Well, it's speculation. Maybe if McDonnell had gotten the contract. Or maybe some lesser, non-fatal accident would have adjusted the culture. We'll never know.

 

[Athelstane]

Hello Michel,

Love the cartoon.

 

[Workable Goblin]

Not to defend North American's conduct - it was a questionable decision to give them the CSM bid - but the problem wasn't so much the greater complexity of systems (they were more complex, but not so much as some might think), as it was the problem of the culture - not just at North American, but at NASA itself.

That culture had not resulted in disaster on Gemini, but was becoming a problem with Apollo. (How long, for example, were they going to get away with a pure oxygen environment? That was NASA's decision, not North American's.)

There's a paragraph in Murray and Cox's book (p. 160) that brought this home to me:

Yes, the culture was a problem. But they did have plenty of time to work on the spacecraft and develop it. With six years having passed between the start of work and 1967, why were people around the time of the fire feeling that "a lot of things had been put up on the shelf as being the kind of thing--'Well, let's not worry about that right now, we'll pick it up later'" or that after the fire they "had the time to go back and work in a less pressured fashion"? This was six years since the contract had been awarded! Most of the basic features of the spacecraft had been fixed for that long! There wasn't any need to "put things up on the shelf" or work "in a pressured fashion" to begin with!

Compare to, say, the Space Shuttle; despite being vastly larger and more complicated, and developed on a smaller budget (~$6.5 billion then-year dollars for development, versus about $8 billion 1969 dollars for just Apollo itself, though possibly including procurement and the LM), and built by the same people, it was developed from program start to first flight in nine years, only 50% longer than the planned development time for the CSM, and encountered no problems nearly as severe as Block I Apollo, at least until Challenger. If NASA and North American couldn't build Apollo reasonably well under those conditions, then it speaks to a severe failure of management in both places (and North American had at least some scope to push back against NASA requests, as spacecraft contractor). The race conditions were an excuse, not a cause, and a PoD altering management earlier could almost certainly lead to Apollo being successfully launched from 1967 onwards with no fires or other disasters.

 

[Athelstane]

WG,

These are all very good questions. But I think it underlines the problematic mindset that was at work at APSO, not just North American. A mindset is harder to fix than a poor wiring layout.

If I were looking for a simple fix to reduce (not eliminate, but reduce) the chances for a fatal disaster with Apollo, I'd probably select a different contractor, probably McDonnell. That wouldn't fix the APSO oversight culture, but it would put a more competent, more experienced contractor in place building the thing. You likely wouldn't have such sloppy wiring, for example.

I like Brovane's awareness of the need to address the Apollo 1 fire to make his NASA-wank possible. I just think that it would take a lot more than Al Shepard raising hell. A lot of what made it possible for the likes of Schirra, Borman, et al to demand design changes was the fire itself; it empowered them in a way they had not been before. Everyone had it brought home to them what the stakes were. No one wanted another disaster.

 

[Athelstane]

More on the problems at North American from Murray and Cox (p. 165) :

Taking up the ASPO job in early April, Low began dictating a daily memorandum to Gilruth, usually two or three typewritten pages, summarizing the day’s activities. A few weeks later, returning from a trip to the North American plant in Downey, he wrote: “My general impression after this week’s visit is that Dale Myers, Charlie Feltz, and George Jeffs are trying extremely hard to do the right things... The next level below them, however, disturbs me.” Frank Borman, writing of that period in his autobiography, put it more bluntly: “North American was positively schizophrenic, populated by conscientious men who knew what they were doing and at least an equal number who didn’t know their butts from third base.” After four years of prodding and pushing from ASPO and headquarters, even after the embarrassment of the Phillips Report, North American remained a problem.

But the cultural problem wasn't just at North American.

I dislike timelines with multiple independent points of departure, as a rule; the result ends up less plausible, at least to me. If we're trying to wank NASA, the most essential thing is a more vigorous, sustained Soviet program (this is the strongest selling point of Brovane's timeline, to me); the resulting political imperative will override a lot of obstacles and setbacks. It's not clear to me how that would butterfly away the decision to hire North American. Perhaps I need to think about that some more.

 

[brovane]

WG,

These are all very good questions. But I think it underlines the problematic mindset that was at work at APSO, not just North American. A mindset is harder to fix than a poor wiring layout.

If I were looking for a simple fix to reduce (not eliminate, but reduce) the chances for a fatal disaster with Apollo, I'd probably select a different contractor, probably McDonnell. That wouldn't fix the APSO oversight culture, but it would put a more competent, more experienced contractor in place building the thing. You likely wouldn't have such sloppy wiring, for example.

I like Brovane's awareness of the need to address the Apollo 1 fire to make his NASA-wank possible. I just think that it would take a lot more than Al Shepard raising hell. A lot of what made it possible for the likes of Schirra, Borman, et al to demand design changes was the fire itself; it empowered them in a way they had not been before. Everyone had it brought home to them what the stakes were. No one wanted another disaster.

It wasn't just Shepard. In large command structures you can have issues with information not filtering to the top. In my ATL Shepard raises hell with Slayton and threatens that he is going to just pickup the phone to call President Kennedy. I assume that if Al Shepard wanted to reach out to the President he could get ahold of him, or at least Slayton believed him. Kennedy's fascination with all things NASA and Shepard being the first man in space. This forces Slayton to take action and he goes to a critical person, General Phillips who is the director of the Apollo Manned lunar landing program. Basically Slayton goes directly to a Military USAF General, both being military and skips over several levels of command chain. With both Phillips and Slayton being service men, Phillips makes time to hear Slayton's concerns which are Shepard's concerns. Phillips is already critical of North American. He does a un-announced inspection of CM-12 and sees the issues first hand including finding a North American tool left behind a panel. At this point things start steamrolling once Phillips gets involved.

The entire situation of problems not filtering up was brought home to me earlier this year in my employment. My employer is getting ready to sell a building where we have a 2,000 square raised floor Datacenter. I am the project manager to move that Datacenter, but get this I was given a zero dollar budget. Basically nobody accounted for IT having to move the Datacenter when the building was sold. My direct boss raised this issue several times and he just got back from up the chain that it was being looked into. So in January or Senior VP of IT came to visit or site, basically my bosses, boss, boss, boss and after the normal speech and Powerpoint he asked if their was any questions. Well I raised my hand and said I have been told to move a Datacenter with a zero dollar budget and I think someplace there is a disconnect above me. The senior VP looked at me and I could tell he couldn't believe what he was hearing. He was like what is your name? At this point I was like here it goes, getting fired now. I told him my name and he turned around to the rest of the group and said this is exactly the type of stuff that I want brought to my attention and he told me he would fix it. Within one week he had found who was in charge of selling the building in or Real Estate department on the East Coast and had gotten commitment from them that the IT expense for moving out of the Datacenter would be charged back to the sale price of the building. I now have a 1 Million dollar budget for the datacenter move. Just by kicking at the right tree.

 

[jsb]

Compare to, say, the Space Shuttle; despite being vastly larger and more complicated, and developed on a smaller budget (~$6.5 billion then-year dollars for development, versus about $8 billion 1969 dollars for just Apollo itself, though possibly including procurement and the LM), and built by the same people, it was developed from program start to first flight in nine years, only 50% longer than the planned development time for the CSM, and encountered no problems nearly as severe as Block I Apollo, at least until Challenger. ....

Is it reasonable to compare them ? by the time you get to designing the shuttle you know a lot more about space and equipment in it than you do early on, how many parts on the shuttle are 'based on' or 'just slightly changed' from stuff used earlier using information gained from the earlier programs ?