If this program didn't go black, then it needs to be revived.
Posted on 05/18/2003 5:23:01 PM PDT by anymouse
A highly-regarded spacecraft designer says the space shuttle should be retired and the human space program suspended until a better vehicle can be built.
This newest critic is Max Faget, 81, who designed the Mercury space capsule and had a managing role in the design of other U.S. human launch systems, including the space shuttle, Apollo and Gemini. He has received almost every commendation that exists for engineers and was inducted into the Ohio-based National Inventor's Hall of Fame earlier this year.
"The bottom line is that the shuttle is too old," Faget said this week. "It would be very difficult to make sure it is in good shape. We ought to just stop going into space until we get a good vehicle. If we aren't willing to spend the money to do that, then we should be ashamed of ourselves."
Faget (pronounced fah-ZHAY), director of engineering for human spacecraft design at NASA for 20 years, was blunt in his criticism of the growing U.S. reliance on the Soyuz. The craft ran into problems this month when a three-man crew returning from the space station landed hundreds of miles off course.
NASA engineers at the working level said privately that they regarded Faget as "a giant in the space community whose opinions are worth more than anybody else's."
In Faget's view, the choices are obvious.
"We ought to get a decent vehicle," he said. "It could carry fewer people, but it ought to be a new vehicle."
Faget said such a program might make sense, but he questioned why anybody would use the same shuttle architecture that he pioneered almost 30 years ago.
(Excerpt) Read more at kansascity.com ...
If this program didn't go black, then it needs to be revived.
After we get back Titan II / Atlas as a manned program, then we can do design and development on complex new vehicles.
On another note, Nasa should have over the years researched ways to replace those fragile heat-tiles. If they'd have done that, and replaced the tiles with a more robust material, we may have not lost Columbia.
Dr. Pournelle: I pointed out that the total weights he comes up with are absurd: while we are not sure that a 600,000 pound GLOW will have a payload to orbit at all, it will certainly be close, and it may even have up to 6,000 pounds: it depends in large part on drag and engine efficiencies, and all those numbers are in the third decimal place. We need to FLY things to see.
The late Max Hunter was willing to be that if you fly a 600,000 pound GLOW VTOL system he could "nickel and dime" it to orbit, and then design a better one that would have the 6,000 pound payload. I never say anyone win a rockets argument with Max, and that includes me, and I tried.
USAF/SDIO Project Have Region established that we know how to build structures that can achieve the mass ratios required to get a 600,000 pound VTOL ship to orbit, and they are strong enough.
I said as much to my correspondent who replied:
"Dr. Pournelle
I spent a brief time attached to an IRAD product development team. We looked into different types of launch configurations. Unfortunately money ran out after about a year and I went back to more mundane endeavors. However, during that time, I was a great--in my opinion--creater of concepts. Unfortunately, my bane and archnemisis was the weights guy. I could show him my calculations on the mass per square foot of pressurized isogrid aluminum with matching FEA and he would show me his statistical database on weight trends in all kinds of vehicles going back to the Wright brothers. I couldn't go into a meeting and tout my concept unless I got Mr. X's ok. Hence, I learned to include a certain amount of conservatism. Nobody wants to invest billions of dollars in a SSTO to discover late in the game that you've got weight growth. As you know, a little bit of weight growth in a SSTO means that it comes out of payload. Too much weight growth and you've got zero payload and money down the drain. I was not involved in X-33, but I watched their oscillations and I knew they were adding mass and losing capability every time they did a loads/weight iteration. I may be too conservative in my estimates, but that was just beaten into me by people who literally laughed in my face. You may say a 5,000 pound payload with a 600,000 GLOW, but get someone to invest $50 million on a full up design study and see what kind of final GLOW comes out.
P.S.
It's all your fault you know. I was just a kid that liked to read science fiction until that issue of Galaxy came out crammed with rocket and orbital mechanics equations. For me, it was a step farther out. We will get to space eventually, but it will take a market for lots of launches, and whether that market is tourists, refueling laser ABMs or something completely different I don't know.
(name withheld)
Pournelle: To which I can only reply, we DID that. The result was DC/X because the big doubt in those days was whether you could control a VTOL ship at low speeds and altitudes (you can; we flew it); and HAVE REGION, which was intended to determine if structures that would meet the strength and weight requirements for SSTO were possible (they build them and they were).
The next step was the full 600,000 pound vehicle, which would have cost in the $1 billion range if that. The DC/X team thought they could do it for hundreds of millions at most. But the project was hijacked by Lockheed which promised the Moon and sixpence and substantial company investment in the winged abortion X-33 which had irregular shaped tanks, wings that required all kinds of dynamic flight adjustments because as fuel is consumed the CG changes and other things happen, and a linear aerospike engine that never worked properly.
The $50 million full up design study isn't the problem. Much of that was done in SDIO where they ended up with a 1.4 million pound GLOW vehicle to assure some 15,000 pound payload to meet some mission requirement. Dan Quayle wasn't able to get enough money to build anything that large, so the result was DC/X which was a 1/3 scale model of the SSX that Hunter, Graham, and I sold him. That story has been told here often enough.
The X-33 experience was expensive but not instructive: nearly everything that happened was predictable and predicted at least by me.
You do not want wings on an experimental development X project space ship. You want pure rockets. You want VTOL. You want to fly.
You want
Savable
Reusable
Fly Early
Fly often
Fly higher and faster
And mostly you want to fly. From that we can learn things about optimum configurations. X-33 was none of the above.
As to the X-33 people laughing, if I had just taken all the money and eaten the dream to achieve nothing, I might have a slightly different emotion. They ought to be ashamed.
The problem is that we do not have enough flight data to establish what we need to have a savable and reusable ship. And everyone seems to have forgotten that SSX was an X SHIP, intended to help us learn how to build an orbiter that would be Savable, etc. Along came X-33 to siphon off all the money on a final design and which was to an X ship as a rabbit hunter is to a rabbit.
It was the insulation on the external tank, not the tiles on the shutle orbitor that was changed for not being environmentally correct. The tiles are merely old technology. Besides it probably was the wing leading edge not the tiles. The leading edges are different than the tiles which cover parts of the wings and fuseloge.
Something like putting rubber tires on a horse buggie, yes, that should really put us into a new learning curve.
prisoner6
Something like this was done in 1988, as an interim launch vehicle, in the aftermath of Challanger. The Titan IV went from contract to hot fire test in 18 months. It was a Titan III upgrade. The Titan II refurbishment was not as sucessful, these silo queens experienced stress corrosion cracking from the Cape salt air.
All of the old hands that worked on Titan and Atlas when it was a man rated vehicle are dead or retired. It would be a lot harder to start up the program today. Much of the production machinery is out dated or was sold off in the 1990's.
Why do you tell us what the advantages of manned space craft are. I can't think of any.
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