Free Republic
Browse · Search
News/Activism
Topics · Post Article

Skip to comments.

Time to Revisit the Aerospace Plane Concept in Light of this Disaster
self | 02/01/03 | LS

Posted on 02/01/2003 9:25:09 AM PST by LS

In light of today's Columbia disaster, it is perhaps time to revisit the intentions behind the now-cancelled National Aerospace Plane (the X-30) program. That program, in many ways, addressed what are apparently many of the problems that led to this explosion and loss of life.

In the early 1980s, the Reagan Administration, through DARPA (the Defense Advanced Projects Research Agency) formed a team of services (the Air Force, Navy, Strategic Defense) and NASA to design and build a scramjet-powered spaceplane that had aicraft-like operational characteristics. The goal was to make a space plane that was genuinely reusable, unlike the shuttles, which require tremendous overhead, support, and time to launch. As much as anything, this feature of the Aerospace Plane would have afforded quick response to emergencies in space---something we simply do not have today. More than that, its design, operation, and construction, while not eliminating all of the problems that have plagued the shuttles, offered some solutions to those we have seen.

Briefly, the X-30 was conceived as a 50-000-lb. swept-wing aircraft that "was" a flying engine. The forebody was an intake; the aft, an exhaust. Several giant scramjet engines were conceived to power this vessel on liquid slush hydrogen fuel. But the beauty of the scramjet was that it mixed the hydrogen with the air outside, giving off water vapor as a by-product. The significance of this concept should not be minimized: by using rockets, a shuttle essentially is like Columbus needing to take the water he sails through along with him. But the X-30 proposed to use the medium of air as PART of the fuel mixture.

Ultimately, the scramjet technology halted the whole program. In 1995, it was killed because the scramjets had not come along as fast as hoped. This, it turned out, was a flaw, not in the techology itself, but in the way the program was "sold" to the administration and the congress. I will return to this in a moment. What is important, though, is that the design of the aircraft used radical new materials for a thick "skin" that eliminated the need for the Shuttle-type tiles---which apparently is where some of the problems originated with Columbia. But even if this is not the case, in voyage after voyage, the expensive tiles simply burn up, and must be completely replaced after one flight. That is not a characteristic of "routine" flight!

How could the Aerospace Plane keep cool enough to survive the phenomenal temperatures? Again, the key was in the frozen slush fuel. In another radical design---and one aspect of the program that appeared to work to perfection---the frozen slushy hydrogen was pumped THROUGH the aircraft, to the leading edges of the wings and nose first, then to less hot areas, then finally to the engines, where it was burned. Thus, the fuel's journey heated it for burning, while cooling the aircraft's (already radically improved) metal edges.

In the seven years I served as the NASP program historian, the engineers and scientists made light-year leaps in materials, producing and manufacturing radical new compound materials that jacked up the ability of a leading edge to sustain heat. During that same time, the program effectively made, stored, pumped, and burned hydrogen slush fuel---one of its most visible triumphs.

This comes only a few days after the President announced a new government initiative to research hydrogen power for cars. It is an idea whose time has come, although Ronald Reagan thought of it first when he embraced the X-30 program.

There were several, substantial, technical hurdles in the program, but most were overcome. The greatest obstacle remained getting the scramjet to perform at levels that would allow speeds of Mach 10, Mach 20, and Mach 25 to reach orbit. Needless to say, this was a titanic feat. Still, the potential benefits of aircraft-like performance addressed several issues that have plagued the shuttles.

*Powered landings. If a shuttle had power in descent, rather than free-falling like a rock, and problems developed, having the ability to pull up or even slow the descent might make the difference between life and death. Certainly if the vehicle gets below 20,000 feet, power can make all the difference in the world. NASP would have had it; the shuttles don't.

*Routine aircraft-like operations (i.e., horizontal take-off, for example) eliminate the massive infrastructures of the shuttles, and could allow rescue attempts for astronauts stranded in space, or to ship needed repair items or equipment to them. Such an option does not exist today.

*X-30 design promised to eliminate many of the tile-related/o-ring related problems of the shuttles. There would be certainly very little rocket fuel aboard (only enough for space-maneuvering rockets). There would OBVIOUSLY be new challenges, and new equipment failures, but we could at least escape some of the weaknesses of the shuttle system.

So what happened to the Aerospace Plane? Robert Williams, the genius behind the program, determined that he could only get funding if he "sold" the administration and Congress on an actual aircraft---not scramjet engines or tests. Thus, he put the cart before the horse, but did get his funding. A further hurdle involved the fact that the U.S. HAS NO wind tunnels of testing any speed higher than Mach 8, and then only for fractions of a second. Instead of building massive new tunnels, Williams planned to make the aircraft into an X-15-type flying test bed, but on a much grander scale.

Unfortunately, the program could not suffer any technical setbacks, because setbacks caused schedule extensions, which cost more money, which caused Congress to stretch out the program yet again. Ever stretch-out ended up taking money from tne X-30 budget, until finally, all the program could do was to fund scramjet tests---exactly what it should have done when the program first started, but which were politically inexpedient.

The U.S. needs to come to grips with the reality that the shuttles are not "routine space access" vehicles, and never will be. Instead, we need to re-focus our space program on a new, hydrogen-fueled vehicle with airplane-like operations, with or without rocket assist.

When our space missions receive no media coverage, or draw no spectators, only then will we have achieved truly "routine" space access. (When was the last time people shook hands and cried when you started your car?)

Shuttles were a good design for the 1970s. It's time for NASA, and America, to come into the 21st century with a new spaceplane that acts like a taxi or a truck, not the Titanic.


TOPICS: Government; News/Current Events
KEYWORDS: columbia; columbiatragedy; feb12003; india; israel; nasa; scramjet; spaceplane; spaceshuttle; ssto; unitedstates

1 posted on 02/01/2003 9:25:09 AM PST by LS
[ Post Reply | Private Reply | View Replies]

To: LS
Of course, but it got cancelled because of the inordinate amount of funding it required. I would like to see new concepts designed that can do things more effectively and efficiently. We can do that, but it does require a lot of work.
2 posted on 02/01/2003 9:35:26 AM PST by rs79bm
[ Post Reply | Private Reply | To 1 | View Replies]

To: LS
NASA last year had started to put out bids for engineering studies on a replacement for the Space Shuttle that would be flying in the next decade. It looks like that project will have to be accelerated with the unfortunate loss of Columbia. :-(

I agree it's time to revive the aerospace plane idea. Besides the fact you no longer need complicated vertical launch facilities, it also means the aerospace plane could operate from anywhere in the world that has at least a 12,000 foot runway. The only infrastructure improvements besides new hangers to store and service the aerospace plane is fuelling facilities for liquid methane or hydrogen slush fuel that the aerospace plane will need.

3 posted on 02/01/2003 9:36:16 AM PST by RayChuang88 (Not a good day today)
[ Post Reply | Private Reply | To 1 | View Replies]

To: LS
Time to Revisit the Aerospace Plane Concept in Light of this Disaster Can we grieve, first?
4 posted on 02/01/2003 9:36:38 AM PST by ImaGraftedBranch (Education starts in the home. Education stops in the public schools)
[ Post Reply | Private Reply | To 1 | View Replies]

To: LS
Thanks for the opinion. Sounds reasonable to me.
5 posted on 02/01/2003 9:38:42 AM PST by the_doc
[ Post Reply | Private Reply | To 1 | View Replies]

Comment #6 Removed by Moderator

To: ImaGraftedBranch
Can we grieve, first?
BUMP!!
7 posted on 02/01/2003 9:45:31 AM PST by evolved_rage (Kill a commie for mommie)
[ Post Reply | Private Reply | To 4 | View Replies]

To: LS
I don't get it.

"... the frozen slushy hydrogen was pumped THROUGH the aircraft, to the leading edges of the wings and nose first, then to less hot areas, then finally to the engines, where it was burned..."

The ship doesn't need to burn fuel on re-entry; the problem is an EXCESS of speed! Fuel is burned only at takeoff, to GET to orbital speed. Thus - what's left for re-entry cooling? Explain, please.

And liquid slush hydroden? Never heard of that.
8 posted on 02/01/2003 9:51:50 AM PST by canuck_conservative
[ Post Reply | Private Reply | To 1 | View Replies]

To: LS
Bump
9 posted on 02/01/2003 9:53:30 AM PST by weikel (Your commie has no regard for human life not even his own)
[ Post Reply | Private Reply | To 1 | View Replies]

To: LS
It seems like an incredible waste of human life......just to study "dust". Couldn't this mission have been completed by an unmanned space drone?
10 posted on 02/01/2003 9:53:33 AM PST by taxed2death
[ Post Reply | Private Reply | To 1 | View Replies]

To: Privatize NASA
I agree we should phase in a privitazation of NASA( a military space branch should be retained). However what happened today was a tragedy and NASA isn't staffed with morons like most gov agencies.
11 posted on 02/01/2003 9:54:55 AM PST by weikel (Your commie has no regard for human life not even his own)
[ Post Reply | Private Reply | To 6 | View Replies]

Comment #12 Removed by Moderator

To: LS
it is perhaps time to revisit the intentions behind the now-cancelled National Aerospace Plane (the X-30) program.

I worked on the Shuttle program when its only flights were still in wind-tunnels ('73-'75). The Shuttles are long past their time -- but NASA has become so encumbered by bureaucracy I wouldn't expect to see anythng new without a HUGE infusion of cash. (It was while I was there, 30 years ago, that one of the scientists observed a bleak milestone attained: NASA's staffing had reached the level one bureaucrat for each researcher.)

13 posted on 02/01/2003 9:58:04 AM PST by Eala (Columbia crew, requiescat in pace)
[ Post Reply | Private Reply | To 1 | View Replies]

To: weikel
Unfortunately, that isn't true any more. A few years ago NASA officially passed the 1 to 1 mark for the ratio of scientists to bureaucrats. :o(
14 posted on 02/01/2003 10:01:10 AM PST by Constantine XIII
[ Post Reply | Private Reply | To 11 | View Replies]

To: ImaGraftedBranch
Agreed!!
15 posted on 02/01/2003 10:02:15 AM PST by Mfkmmof4
[ Post Reply | Private Reply | To 4 | View Replies]

To: LS
the need for the Shuttle-type tiles

Those tiles were amazing stuff in their day. Tough enough to survive the rigors of re-entry, light enough for the application, and providing an amazing amount of insulation. But there was always concern about them -- the last program I worked on at NASA was an ultra-high-speed wind-tunnel test to see how well a tile would stand up to the dynamic forces encountered during re-entry.

16 posted on 02/01/2003 10:03:27 AM PST by Eala (Columbia crew, requiescat in pace)
[ Post Reply | Private Reply | To 1 | View Replies]

To: LS
The Orbital Space Plane project could be sped up, it is time to think seriously where NASA should be going with it's launch system. A positive direction could result from this, where we get a safer, less complex, less expensive means of getting people into space. In an ideal world, NASA would simply buy tickets on a private company's launch system to get to the ISS. Unfortunately no private company has such a system but I expect that to change in the next decade.
17 posted on 02/01/2003 10:04:45 AM PST by Brett66
[ Post Reply | Private Reply | To 1 | View Replies]

To: taxed2death
We may need to send people into space for military research necessity, but with advancements in computer technology there is no reason for our government to be sending civilians into space.
18 posted on 02/01/2003 10:05:35 AM PST by Atlas Sneezed
[ Post Reply | Private Reply | To 10 | View Replies]

To: Constantine XIII
Oh. Well there is your problem. So the buereaucrats outnumber the technocrats...
19 posted on 02/01/2003 10:14:44 AM PST by weikel (Your commie has no regard for human life not even his own)
[ Post Reply | Private Reply | To 14 | View Replies]

To: LS
Shuttle technology is 40 years old.
20 posted on 02/01/2003 10:14:56 AM PST by jaz.357
[ Post Reply | Private Reply | To 1 | View Replies]

To: Eala
Yep. I discovered, when I wrote my history of NASP, that NASA never believed in the scramjet, but went along to get the money. It was an abuse. The AF, however, believed in the scram, and wanted to make it work. Had NASA put its heart into the program, I think today we'd have an airbreathing engine that could go at least Mach 8, and maybe 10.
21 posted on 02/01/2003 10:27:00 AM PST by LS
[ Post Reply | Private Reply | To 13 | View Replies]

To: canuck_conservative
I know you never heard of it. That's the point. With any POWERED vehicle, you must save some fuel. You are still operating in a shuttle mentality that we were trying to escape. Notice a 747 doesn't want to get rid of all fuel before it lands. A lot, yes. But POWERED re-entry is much more desirable than gliding.
22 posted on 02/01/2003 10:28:37 AM PST by LS
[ Post Reply | Private Reply | To 8 | View Replies]

To: Privatize NASA
If you care to read my study, a shortened copy is available in "Air Power History" 1994. However, in my final report to the Air Force (and throughout) I constantly fought for more privatizing of the space effort.

To an extent, the Aerospace Plane did take steps in that direction. First, several air contractors participated in the main program (McDonnell Doug., Rockwell, P&W, Rocketdyne, GD, and, earlier, Lockheed and Boeing). I'm convinced that had the program put a usable prototype out, you WOULD have seen private-sector copycats fairly soon.

One of my jobs was to figure out how to advance the technology and make recommendations. I recommended a national prize for single-stage-to-orbit, wherein I'm convinced a private firm would quickly give us the technology we want for a fraction of the cost of NASA's programs.

But realistically, if you think the U.S. is going to disband NASA, it won't happen, and therefore REALISTICALLY the best we can do is to constantly push NASA toward more privatization in every area. (BTW, Soyuz is a government program).

23 posted on 02/01/2003 10:34:11 AM PST by LS
[ Post Reply | Private Reply | To 6 | View Replies]

To: ImaGraftedBranch
My point is that if we had supported NASP in 1986 after Challenger, we might not have to grieve first.
24 posted on 02/01/2003 10:34:58 AM PST by LS
[ Post Reply | Private Reply | To 4 | View Replies]

To: RayChuang88
Exactly. And the NASP program proved they could STORE and PUMP the hydrogen, so it is feasible.
25 posted on 02/01/2003 10:35:44 AM PST by LS
[ Post Reply | Private Reply | To 3 | View Replies]

To: YourMaster
Your a prince. Bashing American technology before the facts are in while offering condolences is right out of the DNC play book.
26 posted on 02/01/2003 10:36:20 AM PST by ffusco (sempre ragione)
[ Post Reply | Private Reply | To 12 | View Replies]

To: rs79bm
It did not require an "inordinate" amount of funding, especially for the technological problems it tackled. But my point was that every DELAY and government STRETCH-OUT actually INCREASED the cost. I remember, after one stretched out budget came back, that the managers sat around a table cancelling a dozen tests, or pushing them back. Each time, they would note how much cancelling or pushing it back COST THE TAXPAYER and would shake their heads.
27 posted on 02/01/2003 10:37:32 AM PST by LS
[ Post Reply | Private Reply | To 2 | View Replies]

To: evolved_rage
Can we grieve, first?

With all due respect, I really wonder how much grieving I can do for people whose names I never even knew until this morning. There's authentic emotion, and then there's the synthetic kind which intellectually intimidated people like using in order to belittle those who are intellectually capable of thinking up solutions to prevent future tragedies.

Technically-knowledgeable people often respond to tragic circumstances by trying to think up solutions. This is not coldly insensitive; it is wonderfully appropriate. And in its own way, it is the sincerest form of demonstrating true grief.

28 posted on 02/01/2003 10:41:15 AM PST by 537 Votes
[ Post Reply | Private Reply | To 7 | View Replies]

To: LS
I, for one, would think that a newer more reliable space bird would be a great memorial to these intrepid souls. But I can understand if others don't want to think about it just yet.
29 posted on 02/01/2003 10:52:29 AM PST by LibKill (ColdWarrior. I stood the watch.)
[ Post Reply | Private Reply | To 1 | View Replies]

To: LS
Airplanes are fine, but they have to re-enter the atmosphere. I would prefer the early space capsule design for getting back to earth over the ability to land near the airport snack bar. Re-think the whole concept and separate crewed launches from freight launches.
30 posted on 02/01/2003 10:58:01 AM PST by RightWhale
[ Post Reply | Private Reply | To 1 | View Replies]

To: LS
Using these space shuttles to operate our space program is like using DC-3's for the main routes on airlines in 2003. It could be done, but there aren't enough DC-3's to do the job satisfactorily, and they are inherently far more cumbersome and inefficient than the third and fourth generation jets which have replaced them.

If we started right now, how soon would the "scram-jet" be operational? What are our other options?
31 posted on 02/01/2003 11:00:34 AM PST by alloysteel
[ Post Reply | Private Reply | To 1 | View Replies]

To: 537 Votes
Technically-knowledgeable people often respond to tragic circumstances by trying to think up solutions. This is not coldly insensitive; it is wonderfully appropriate. And in its own way, it is the sincerest form of demonstrating true grief.

Hear, hear. I ask everyone to consider that this sort of response is exactly what the shuttle crew themselves would consider an appropriate honor. After all, they didn't go into space because they wanted to live forever -- they went to learn and achieve. The risk of life balances the potential win of each mission. They could minimize it, but it never goes away.

Dare nonetheless.

32 posted on 02/01/2003 11:05:21 AM PST by thulldud
[ Post Reply | Private Reply | To 28 | View Replies]

To: 537 Votes
Also, I find myself wondering what we're supposed to be "grieving" about? I must admit that I've not gone through a grieving process for any of our soldiers killed in battle, nor would I expect them to feel the loss if I perished. That doesn't mean that I don't have tremendous gratitude and respect for the sacrafices that they have all made on the nation's behalf.

Rather than grieving for those who perished today, I feel more inclined to honor them, and then to look postively towards the future of America in space. Let us not let the world come to know us as a nation of crybabies, but a nation of bold explorers, a nation in which all citizens have some measure of "The Right Stuff".

33 posted on 02/01/2003 11:05:56 AM PST by The Duke
[ Post Reply | Private Reply | To 28 | View Replies]

To: taxed2death
It seems like an incredible waste of human life......just to study "dust". Couldn't this mission have been completed by an unmanned space drone?

I would rather have three minutes of wonderful than a whole life of nothing special.

There is safety in staying home.... but little chance for complete and absolute amazement.

34 posted on 02/01/2003 11:09:11 AM PST by HairOfTheDog
[ Post Reply | Private Reply | To 10 | View Replies]

To: LS
"But POWERED re-entry is much more desirable than gliding."

Not necessarily. Powered re-entry means you have to carry along a bunch of liquid hydrogen (or whatever fuel) all through the orbital phase and - riskiest of all - the shaking, white-hot heat of upper re-entry. That's a long time for accidents to happen and dangerous as h*ll!

Glide re-entry does have its advantages.
35 posted on 02/01/2003 11:18:41 AM PST by canuck_conservative
[ Post Reply | Private Reply | To 22 | View Replies]

To: LS
Look, the whole thing is still incredibly dangerous. Lives must be risked for manned spaceflight to succeed. We must honor the fallen by aggressively examining all aspects of the program.It's important to know what happened, how it happened, and especially why.

I feel the role of the government should be examined as well. Look at what has happened to all of the alternative launcher initiatives on the part of industry. Any that looked competitive with NASA were sabotaged financially by NASA. A program viable in all other respects must still operate with NASA's blessing.

All that is left of the fallen is an investigation, a memorial, and compassion for family and friends. We owe it to ourselves and the future to not let them die in vain. If we learn anything we must apply those lessons learned. And we must also look back to what is already well known, This is where I climb up on my soapbox, and please don't take this the wrong way.

Asking for a government solution here is asking for more of the same. NASA should be a research organization contracting out research. Building and operating a space fleet should not be in the NASA charter. There do exist current, viable contenders to NASA's space flight and research operations. This includes the Russian program, and private concerns currently operating outside the missle-launcher industrial complex, for example Kistler Aerospace comes to mind. We don't need cadillac programs. The most successful operating spacecraft available today is Soyuz, arguably 1950's era technology. If we want a replacement, a government program is the most backasswards solution, if at all possible. The competition and initiative required for a succesful NASP or SSTO is verifiably not present in the FedGov, or they would have already succeeded after 40 years of trying!

For further insight look up links to the Space Access Society. You won't find it at NASA, except in research.

36 posted on 02/01/2003 11:49:50 AM PST by no-s
[ Post Reply | Private Reply | To 1 | View Replies]

To: alloysteel
I think, giving reasonable funding, you could have an operational Mach 6 scram in about 5-6 years; and after that, the progress goes much faster. We have continued several of these programs at low levels, including "Hyper-X" and two others. They have very low funding, though.
37 posted on 02/01/2003 1:48:08 PM PST by LS
[ Post Reply | Private Reply | To 31 | View Replies]

To: taxed2death
So what about the waste in human life of those who die in accidents at home, including drowning in the tub ?

NOTHING is completely safe.

Explorers do it for love of knowledge and maybe a little fame, later come the pioneers who die learning the best way to survive, and then the settlers who truly make it part of man's domain.

The explorers are still the only ones going into space.

38 posted on 02/01/2003 6:52:21 PM PST by hoosierham
[ Post Reply | Private Reply | To 10 | View Replies]

To: evolved_rage
No. We need to move forward, and to do so aggressively. Anything else would be an insult.
39 posted on 02/01/2003 6:55:45 PM PST by Chancellor Palpatine (toward an unassailable America)
[ Post Reply | Private Reply | To 7 | View Replies]

To: LS
Shuttles were a good design for the 1970s. It's time for NASA, and America, to come into the 21st century with a new spaceplane that acts like a taxi or a truck, not the Titanic.

One way of looking at it is this: I wouldn't think of driving down I95 in a 20-year-old car; why would anybody want to go to space in a 20-year-old space vehicle?

40 posted on 02/01/2003 7:02:13 PM PST by merak
[ Post Reply | Private Reply | To 1 | View Replies]

To: Chancellor Palpatine
I worked on the X-30 project at General Dynamics in Fort Worth. Slush hydrogen was used to get better fuel density. Other things were used for oxidizor (classified then, maybe now) The X-30 was a materials marvel, it could fly through the heat of a volcano. There were rockets at Mach 17+ due to push to space, no air. The problem was the size. Too heavy. Never could get it down. I can't remember the exact fuel eater. We have materials that can take re-entry heat that have structural strength. NASP was made of it.
41 posted on 02/01/2003 7:08:05 PM PST by rlbedfor
[ Post Reply | Private Reply | To 39 | View Replies]

To: Chancellor Palpatine
Well, now its 12 hours after the tragedy so anything goes, but at 9:45 am PST, before the deaths were even confirmed, anything but reverence seemed a bit much.
42 posted on 02/01/2003 7:12:18 PM PST by evolved_rage (Kill a commie for mommie)
[ Post Reply | Private Reply | To 39 | View Replies]

To: LS
hydrogen slush fuel

If liquid hydrogen is further cooled (almost to the solidification point) it would form a slush. You wouldn't want to cool it any further otherwise you would have solid hydrogen - that stuff would be hard to pump.

43 posted on 02/01/2003 8:42:17 PM PST by reg45
[ Post Reply | Private Reply | To 1 | View Replies]

Comment #44 Removed by Moderator

To: reg45
Right. That is what I said, wasn't it? When I said "frozen," I meant like a slurpee is "frozen," but not, obviously, solid ice.
45 posted on 02/02/2003 7:27:39 AM PST by LS
[ Post Reply | Private Reply | To 43 | View Replies]

To: merak
Exactly, but in this case it is even worse. By having the GOVERNMENT continue to subsidize the "1950s car technology," we are blocking or, at the very least, not funding, 21st century technology. There should have been a cut off on all Shuttle development, improvement, etc., and a new system begun years ago.
46 posted on 02/02/2003 7:29:02 AM PST by LS
[ Post Reply | Private Reply | To 40 | View Replies]

To: no-s
It's not necessarily true that SSTO won't work "because they quit trying." Many ideas need "vicinities" effects to work. For ex., the internal combustion engine was invented before Henry Ford, and even Ford's cars really didn't transform transportation until several things were in place: good rubber for tires; glass; a critical mass of car owners who demanded better (or any!) roads; Kettering's automatic starter; cheap gas (thank you, Mr. Rockefeller); and a host of other technological innovations that made a car worth OWNING. The same is true with scrams and SSTO: the challenges were so great that NASP had to master all at once. I think the program did a whale of a job getting the materials, the computational fluid dynamics (itself a remarkable breakthrough) and the slush hydrogen. Yes, the engine is key. But few engineers I've talked to think it is impossible---just that they haven't quite hit on the best way of doing it yet.

I think SSTO is the ONLY solution to space travel of any sort. Otherwise, there will never be a true "space station" of the "2001" type built.

47 posted on 02/02/2003 7:33:25 AM PST by LS
[ Post Reply | Private Reply | To 36 | View Replies]

To: LS
I didn't say It's not necessarily true that SSTO won't work "because they quit trying.".

My thinking is they (Gov't programs) are incompetent to make it work. Gov't programs can not change gears fast enough to complete the engineering before funding runs out, and we exchange engineering for funding pursuit. When engineering takes a backseat to marketing, there's plenty of opportunity for Feynman's observation about successful technology to creep in:
For a successful technology, reality must take precedence over public relations, for Nature can not be fooled.

SSTO is very hard. The mass ratio is a killer, because after you add the return systems your payload fraction goes to nil. Given, of course, 1990's engineered materials. NASP is an application of the first obvious, air for oxidizer to improve mass ratio. Scramjet and ramjet engines have an extraordinarily high thrust to weight ratio (I've seen claims of 1000:1 for ramjets). But the physics of flying at high speed in atmosphere conspire to create a huge ding in the mass ratio again. It's not a linear relation.It's not optimal for all missions. It's not a one-size-fits-all.

I don't think FR is an adequate debating forum for this, perusing old USENET archives and AIAA papers I can see ample evidence of brighter lights at work on the physics and engineering. If the FEDGOV is going to spend gigabucks on this process I wish they would do it in a way which leverages the efficiencies of capitalism. I will admit I am a fan of TSTO (two stages to orbit). Considering the cost of materials on orbit, I would rather build a space station from discarded rocket boosters than pay to haul them back and forth from orbit over and over again. Lightweight return modules (namely capsules with heat shields) have a plenty good record.

There needs to be an financial incentive to get this going. If we feel it's proper to do as a nation, for Constitutionally supported purposes, then the appropriate thing is for the FEDGOV to get out there and emit the proper perverse incentive, i.e. pay for pound delivered to orbit, pay for person delivered to orbit, pay for surveys, prizes for research and development, etc. Not do the whole enchilada inhouse.

48 posted on 02/02/2003 8:45:00 AM PST by no-s
[ Post Reply | Private Reply | To 47 | View Replies]

To: no-s
We fully agree on the difficulty. I think NASP was an exceptional program in TRYING to privatize this as much as possible. It basically set up a cartel of half the airfram manufacturers in the U.S. (and Grumman really had no shot to begin with, and Boeing wasn't that interested); and of 2/3s of the propulsion contractors. So they tried to get a "consortium" or cartel of everyone. Then the government backed off a great deal, allowing the contractors to meet the mission requirements.

One of the problems from the get-go was that this was supposed to be an X program, meaning a test program to measure things. But to get the AF to sign on, they had to demonstrate a payload bay door. That added thousands of pounds of weight. A 50,000 design ballooned to 500,000, and that was too big. Most of the experts---private and government alike---think they can beat the thrust over drag at lower weights.

49 posted on 02/02/2003 1:14:56 PM PST by LS
[ Post Reply | Private Reply | To 48 | View Replies]

Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.

Free Republic
Browse · Search
News/Activism
Topics · Post Article

FreeRepublic, LLC, PO BOX 9771, FRESNO, CA 93794
FreeRepublic.com is powered by software copyright 2000-2008 John Robinson