Slashdot Mirror
Bad Testing Doomed NASA's Hypersonic X-43A
RobertB-DC writes "Space.com got hold of NASA's yet-to-be-released report on the June 2001 failure of the air-breathing X-43A hypersonic research vehicle, and it doesn't look good for 'Faster, Better, Cheaper'. The report refuses to single out any one contributing factor, but it cites ground testing 'inaccuracies' and 'misinterpretation' of wind tunnel data -- in particular, failure to retest the vehicle after additional heat protection was added. As noted in the original Slashdot article, the craft went out of control when the fins broke off just seconds into flight."
You know, stuff like this really inspires me. I'm in the middle of reading Kings of the High Frontier, which was first published in the mid-nineties. A major plot point is a wealthy industrialist offering a half-billion dollar prize similar to the X-Prize. Even a few years ago, I never thought we'd be seeing so many groups trying for their own cheap launch. It should have been done years ago.
Some people complain that the X-Prize doesn't really get anywhere---that tossing yourself a hundred kilometers above sea level is a far cry from low earth orbit. This is true. Maybe the X-Prize will be the first in a series of cash prizes to spur even more invention. First single-stage to orbit, first real space station, first craft assembled in space... I don't know what the next milestones will be, but we'll get there faster if there's cash money incentive.
Oh, and would wetsuits work as space suits? There's no way the heat would really bleed off, and if you could lead-line them for heat shielding...
The quote from KOTHF is "Space suits for NASA cost a million bucks a shot and are about as comfortable as wearing pork barrels. I found this research report from the nineteen-sixties by a team that ought to have won the contract bid, except that their suits only cost a thousand dollars each and could be done by any seamstress. NASA probably figured that would have looked cheap, so for three decades astronauts have been lugging around thirty layers of cloth and a refrigerator when they could have been dressed in Spandex tights." [...] "The difference between down here and up there is only one measly atmosphere of pressure. Our skin is strong enough to withstand that gradient. It has quite a bit of tensile strength. The only problem is that it stretches too well. That means we swell up, which drops the pressure in our bloodstream, so our blood outgasses and vapor-locks our hearts. With just this second skin to keep our body volume constant, we don't expand. So we don't boil." (From ch. 11.)
Can anyone with a background in anything relating to that confirm or deny?
--grendel drago
Laws do not persuade just because they threaten. --Seneca
Not an expert, but have read on this elsewhere:
Wetsuits (probably reinforced with kevlar or something, why not) would probably be fine; actually, filling any small internal gaps with water would be a good trick to insure a perfect fit (any gaps in the suit and you get Giant Space Hickeys, and we don't want that!). You'ld need a fishbowl helmet, of course.
Heat might be tricky. Space is cold, but there's no air, so shedding heat is surprisingly hard. I'm not sure if overheating or freezing would be the main problem for humans in moderately insulated suits.
The X-43A MIB report underscores the fact that the Hyper-X launch vehicle contract was developed under the faster, better, cheaper philosophy
the rules clearly state that you may only choose 2 of the above!!
they didn't train enough!
Banaaaana!
Proud patriot and republican voter.
Why is it that nasa has the philosophy of faster better cheaper? Although it has had some success the philosophy leads to more failure. Its obvious that the public seems to want more space based research, trips to mars, etc. So why does nasa feel that it needs to drop a project at any hint of failure?
-=You might be a geek if your computer is worth more than your car=-
Damn it, Bobby Ted! That JB Weld was supposed to hold them goldang fins on tight....lemme check that thar tube. You dumb ass! It says that it holds in temperatures up to 200 degrees F not 2000! Get that antenna out of your ass!
This comment was randomly generated by a school of piranhas chewing on the PCB of a Microsoft Natural Keyboard.
I personally don't see this governmental fiddling with space lasting much longer, seeing how commercial interests and private (albeit wealthy) citizens are starting to push the cold, dark envelope of space travel. If I could make an outlandish prediction, I'd guess that by 2020, we'll have a ship or two with no real flag-bearing duties on the Moon. I personally hope we find a complete replacement for manned vehicles altogether, but exploration has demands for the flexible, so humans will probably still be risked as a result.
Remember, you don't fly in a "Wright" airplane, it's a Boeing... let commercial interests take over where purist experimentation leaves off.
Windows XP SP2 told me to install third-party software that prevents viruses and protects stability... I chose Ubuntu
You know, I'm not sure that the whole slashdot crowd understands how hard it is to test these sort of things. I mean my university has been doing subcontracting for NASA and I have to say, these people there are really smart. I'm not talking business major to business major, I mean EE to Ph.D EE - these guys are dumb so please don't refer to them as such. Imagine though, any huge project, no matter how well constructed, basically comes down to a single person decieding or desidgning something (the so called single point failure). Do you think you could be that person?
There have been consistent stories in the press about a certain slack in attention to detail at NASA of late. And, as an Air Force guy, I wonder how they could design a wing leading edge that can't take a hit from some hard foam, we get bird-strike all the time! Even a C-17 can take a 30 pound goose at 400 knots...
Nasa as a forward looking organization died in 69. Ever since then its been a zombie a shadow of its former self. Its been almost continuous decline in the post apollo era. Take a look at the programs that followed.
Skylab vs ISS Alpha
Direct easy and done safely v.s. Pointless
X-15 vs X29, X43 and the other spaceplane projects
The only significant manned space vehicle since the apollo program is the shuttle. While it is one thing for hero's to lose their lives in the conquest of a new frontier, its another to lose life because a congressional district in utah needed make work or nasa's beuracracy wouldn't listen to outsiders.
If there is any hope of man in space, it will come from private entrepeneurs and perhaps other countries.
Wow, I've heard of ghetto engineering ... but the fins just flat fell off a second into the flight?! C'mon, I expect much better of NASA. Hell, even I can manage to launch a rocket whose fins will stay fully attached until the parachute burns through and the entire assemblage smacks into the ground, sending fin particles everywhere. But that's MANY seconds after launch, not only a few.
Cyde Weys Musings - Scrutinizing the inscrutable
NASA has some damn smart people working there. NASA does really nice basic research. NASA sucks ass at applying it.
Look at the various inventions that fell out of the space program as little extras. Look at all the technology that was invented. That's what NASA does well.
Now look at the Shuttle, which didn't meet a single one of its design parameters---it's technically not even reusable, it's salvageable. Look at the criminally high cost of launching mass into LEO. Look at NASA's inability to really deliver on the applied end of things. That's what NASA can't do.
I suggest Kings of the High Frontier as required reading for anyone interested in learning how NASA has failed to deliver on its promise of space access due to its fetishization of research-heavy boondoggles. The book is fiction, but extensively researched. (The discussion on unpressurized spacesuits fell out of an off-the-cuff reference the author made.)
Leave it to the X-Prize competitors, and their successors. The Space Shuttle is at the very limit of complexity that's possible to construct, which is why NASA has been unable to replace it. (Did you know there are literally hundreds of "Criticality One" components in the shuttle, the failure of any one of which could cause the shuttle's destruction?)
Okay, this seems like a rant about the Shuttle. But it's really about NASA, and the way in which they do things. It's not an indictment against the people who work there; the scientists and engineers of NASA are without equal. Their efforts are being squandered. The future does not belong to NASA, and it hasn't since they cancelled Apollo.
--grendel drago
Laws do not persuade just because they threaten. --Seneca
I worked for one of the companies involved in this program, although not directly on the program itself.
Let's see, we've got a scramjet test aircraft, which will be boosted to hypersonic speeds by a modified Pegasus rocket, which will be dropped from a B-52. So, besides developing the scramjet test aircraft, an interface system between the Pegasus and the X-43A needs to be designed and the whole system tested.
That didn't bother me too much. What really got me was what the point of the program was in the first place. The goal was to test the ability of a scramjet engine to propel an aircraft at hypersonic speeds. The Pegasus booster was supposed to accelerate the test aircraft to hypersonic speeds, then detach, at which point the scramjet would be started and the instrumentation would transmit 10 seconds of data. Besides the limited amount of data, if I recall correctly, the scramjet was not supposed to even maintain the aircraft's speed, which calls into question the value of the technology as a means of propulsion, in my opinion.
If I recall, the contract value was $33 million, and was significantly overrun. Your tax dollars at work (if you're American).
They'll get my encryption algorithm when they pry it from my cold, dead hard drive.
It's the reason why NASA deceived Congress and underestimated the cost and reliability of the Shuttle. Not a concious conspiracy, just your regular bureaucratic tendency.
Nowadays, the Shuttle is keeping tens of thousands of plushy jobs at NASA. Many of them aren't paper pushers, there are really good engineers working on this program. However, the real top dogs are the bureaucrats. And they know that the Shuttle should be replaced by something that does not require an army to operate, but they'd be out of a job.
Each time the crazy engineers rock the boat and create a potential cheaper competitor for the Shuttle, it magically gets killed. Look at the X-33. Look at the DC-X: This demonstrator was taking off and landing on its jet, vertically. It was perfectly working when it was given to NASA, and somehow, NASA killed it on its first NASA flight. And somehow, the budget to build a new DC-X was consumed by, why, the Shuttle of course. So this perfectly good project was dropped.
See how it works? Tons of examples can be found in the history of the various X-projects that got mysteriously mismanaged and killed since the Shuttle program started.
NASA outlived its utility and became the worst enemy of cheap space access.
You want space access? You want to get to Mars before the Chinese? Keep the JPL and the researchers, get rid of the rest of NASA.
--
Mad science! Robots! Underwear! Cute girls! Full comic online! http://www.girlgeniusonline.com/
- Cheaper
is one helluva factor for it! *shrugs*Remember the Mir? What an amazing success for mankind. It just kept right on working. Even whenever there was anykind of problem that was repaired in space, the American media talked about how it was an aging station and about the "cash-strapped Russian space agency". What comes around goes around I guess. The cash-strapped American space agency now has no manned space flight capability. Russia is the only country on Earth with that ability. The shuttle fleet is too old and if they ever attempt to fly those again they can expect similar results as their last attempt.
What about astrology, the most rediculious of the sciences!
Astrology ain't a science bub, no more than palm reading. Next you'll be telling me John Edwards is a scientist.
But knowitall engineers use trensastors with inferious sound quality just to save a few bucks
And musicians will actually buy them! And a good hunk of the population will love to listen to them. There are three stations on XM radio pretty much devoted to sound coming from transitors. Moby's pretty big but where would he be without the transitor? Now, you may not like him but, as you said, you cannot apply objective reasoning to something that is intrinsicly subjective.
It is a lot of work, but the upshot is improved grammer and spelling skills that are lacking in the technical.
You deserve a +2 Funny for this remark in a post that has some of the worst spelling I have ever seen. I think you should demand your money back if you're being serious.
common sense: noun
What those who are ignorant of the subject matter think; usually wrong.
Something has to be done about NASA. They are clearly far too inadequate to do their job properly.
They ignored their engineers in '86. Astronauts died.
They cant convert units, expensive Mars rovers are lost.
They didnt follow proper safety procedures this year, astronauts died.
They lose prototype planes because they decide not to test added elements. They lose this, and that, and lose billions of dollars doing it.
I dunno about all you other readers, but it seems to me that NASA needs some *serious* restructuring.
This better, faster, cheaper thing has turned out to be broken, slow, and expensive. It's bad enough we lose prototype planes worth billions to their errors, let alone the 14 astronauts sacrificed in the name of saving costs to keep a complex bureaucracy well paid.
Fuck NASA. We need something new.
I am a viral sig. Please copy me and help me spread. Thank you.
Based upon my experience at Goddard, I will say that most of the people at NASA are honest, upstanding individuals intent on doing the best job they can.
Unfortunately, I don't think the management culture they inhabit works the same way. Yes, there are honest people in management. Too often, though, they must fight against pressures forcing dishonesty and abuse.
Some people are quitting the field because of dishonesty and abuse. Donna Shirley, the woman who led the team that designed and built the successful Mars rover of 1997, has quit, citing the "lack of honesty and openness" in the field.
When I was at Goddard, some high level managers in my company were caught defrauding the government out of millions of dollars. As a part of being allowed to continue doing business with the government, the company signed an agreement that forced all employees to receive annual "ethics" training. The training was a joke, emphasizing things like not using government e-mail for personal use. Teaching employees how to recognize major corruption on the part of mid and high level executives? Why, we "worker bees" need not worry our pretty little heads about that sort of thing...
Personally, I think the kind of dishonesty reported in these articles will persist until NASA embraces honesty, openness and democracy in its culture.
NASA should call on (and pay lots of money to) the inimitable Bruce Simpson.
First off... this is my own opinion only, and does not reflect the attitude or thoughts of my employer.... with that said: ...come on... you can do it... put 1 and 1 together... NASA straps their research vehicle to the nose of Orbitals delivery system -- the launch vehicle... OH, is the light dawning yet?... what does the report indicate is the problem? was it the hypersonic vehicle that failed?? NO MORONS, it DOESN'T say that... the VEHICLE never got to the test range!! NASA never got to TEST the friggin vehicle in the first place.
...but like always... you never hear about NASA's THOUSANDS of achievements... I'm willing to bet that most of you can't name a single thing that NASA has contributed to the US technological community...why is that? maybe it's because those achievements never get air time. Achievements aren't juicy enough for the media... Media gets more attention when it focus's on NASA's failures... When was the last time you heard a news organization extolling the virtues of NASA?
I'm not sure whether to be pleased that someone actually took the time to locate a report that's been out for almost three months, or irritated that they (space.com) are completely misleading the public as to the cause and who's to blame for the defect (or that somehow they're privy to information that's available to everyone) which resulted in NASA having to terminate the Launch and Research Vehicle (X43A). On top of that, it's rediculous to post it to a forum like this. Reality check folks... This is a proven technology (hypersonic ram/scramjet engines) which has a large application base, and WILL provide faster, cheaper and cleaner access to space. I appreciate (not really) the folks that seem to get off on putting down NASA's achievments, or summing the work NASA does up to the moon landing (...and depending on who you listen to apparently we made that up too... -- that's sarcasm in case you didn't pick up on it.) If anyone of you has a moment to actually read the MIB report... and more over has the intellectual capacity to understand it (Lord knows no one's displayed that capability here, or at space.com), then you should understand where blame should be placed. The main portion of NASA's work was with the X-43A VEHICLE, and the subcontractor ORBITAL was supposed to provide a delivery system which would get NASA's RESEARCH VEHICLE to the test range. For those of you who can't quite put it all together,
All this criticism of NASA as "incapable", or "no longer with it"... to you folks I say PISS OFF... you have no clue what you're talking about. The X-43 folks are anything but sloppy at the research they do; the managment is outstanding, and the technical expertise is the best in the world.
To folks that think that NASA is just a big bureaucracy; you're absolutely right. They are, just like any other organization that does bleeding edge research and provides outstanding technical work to the US government. Any organization that does the kind of experimental research that NASA does (look around, there aren't any) has to have a legitimate infrastructure in place to handle the costs and managment structure that large experiments have. There is NO way around this, and anyone who thinks there is, is a fool.
To those of you who doubt that the X-43A vehicle will fly... PAY ATTENTION TO WHAT HAPPENS IN THE NEWS IN OCTOBER!
Remind's me of the allegedly true story going the rounds BAE systems in the UK developed a new test rig for testing plane windsceens , a chicken was fired at high velocity at the screen by a giant compressed air gun An american company involved in high speed train developement asked if they could use the design, three weeks later a frantic Email arrived at BAE saying the chicken went through the screen, through the bulkhead and embedded itself in the rear wall of the carriage, what should they do to improve their windsceen, the guy at BAE sent a one line email to them 'DEFOST THE CHICKEN' I tend to think its true as something similar happened to me, I was involved in developing rat poisons, new novel chemicals/drugs are often sent off for evaluation as anti-cancer drugs or in this case to combat strokes (it was an anti-coagulent) the center replied that it was not effective as all the rats died at their standard testing dose DOH RTFM
Certainly I'd agree that Apollo was a better run and much more successful project, but didn't the moon race consume something in the neighbourhood of 10% of the US GDP at the time?
To attempt to put that in perspective, if you think that the war on Iraq was/is expensive, try multiplying it by 10* to get an idea of how much Apollo cost.
What could people really expect? Once the moon race was over, there really was no place for NASA spending to go but down. Less money = Less resource = Less cool stuff that you can pull off.
* Being Canadian, I have excused myself from looking up completely accurate figures. My back of an envelope calculations actually give me closer to 1000 times more expensive (relative to GDP), but that seems rather high... Someone who knows better please feel free to correct me.
As someone who has worked on satellite software development and testing, I can tell you that system complexity is one of the biggest enemies of the 'Faster, Better, Cheaper' philosophy. As the complexity of a spacecraft increases, so does the testing. If you put 10,000 telemetry points into the downlink, then you have to test all 10,000 of them in such a way as to assure that they are fully functional. The same holds true for mechanical complexity and system interaction. When a project is behind schedule and over budget, one of the first things looked at for chopping is the testing.
This is not news to software engineers, but it seems to be something that the general public fails to grasp. NASA needs to revert to the slower, more reliable, more expensive philosophy that brought so much success throughout the sixties and seventies. We need to accept that space exploration is complex and expensive and attempts to shortcut will just result in horrible failures and even the loss of life. Diverting a little money from Bush's "War Against Imaginary Weapons" to NASA would be a good start.
No doubt. Which is why successful FBC missions tend to deliberately work to reduce complexity. That's how they make them fast and cheap. It's a foolish project manager (i.e. one that really doesn't "get" FBC) that tries to implement the "Faster" and "Cheaper" parts of FBC on a mission that is as complex is a non-FBC mission.
NASA needs to revert to the slower, more reliable, more expensive philosophy that brought so much success throughout the sixties and seventies. We need to accept that space exploration is complex and expensive and attempts to shortcut will just result in horrible failures and even the loss of life.
The last thing NASA should do is revert to its old philosophy. That philosophy is appropriate for some missions, but disaster for most: it costs way too much, and provides poor return on investment. FBC, if done right, can provide a much better ROI. Space exploration does not have to be complex and expensive. Look at NEAR, SAMPEX, HETE, Clementine, Lunar Prospector, the AMSATs, Orsted, Freja, Orbcomm, Mars Pathfinder, Beagle, MightySat, RADCAL, or MACSAT. FBC can be done, and done right.
The last thing NASA should do is revert to its old philosophy.
That philosophy put man on the moon. What progress have we made since then? Do we have a lunar colony? Do we have a large, fully-manned space station complete with rotation providing artificial gravity? Have we sent men to Mars? All that FBC has done is provide us with uninspiring baby steps taken with unmanned probes. It's caused an entire generation of kids to decide that being an astronaut isn't nearly as cool as flying a fighter jet.
That philosophy is appropriate for some missions, but disaster for most: it costs way too much, and provides poor return on investment.
We don't need a good return on investment -- we need more investment. NASA's annual budget is less than we are spending every two months occupying Iraq. In the mid-60's, NASA received about 5% of the total federal budget. Now it gets less than 1/2%. We need a President like Kennedy again -- one who values space exploration more than oil exploitation.
Donald Rumsfeld (always) and NASA management will want you to believe that NASA employees are all to blame for failures. We always find out later that the Government civilian worker-bees and pack-mules did all the right things, but management and office (government) politics in the government workplaces did all the wrong things ... too include point the finger at the group that many like to use as an excuse, but they (civilian worker-bees and pack-mules) make no decisions and can only seek permission. Incompetent decisions that sometimes are made by unaccredited university degreed (diploma mill) managers, Bosses, and politicians are the typical today. ... don't cause bank/CU failures, business bankruptcies, criminal fraud and theft in business the majority of failures in our economy/business are due to piss poor performance by management and Bosses not the worker-bees and pack-mules employees. ... failures are due to failures in leadership and delusional denial by management. Credit Unions (CU), Global Crossings, World Com, Enron, ... failures, and Delta and other companies CEOs and staff steeling (lack of a better word) from worker-bees and pack-mules pension funds, reductions in pay, benefits, and health insurance to fund the CEOs' and staffs' ever increasing pay and benefits increases, and then put CEOs' and staffs' retirements in protected trust. .... ...), financial responsibility is a thing of the past, and social security is always secure, because the government can maintain benefits for the wealthy today, and increase the social security retirement age until the right number of US Citizens die and never collect any benefits (old folks don't have many dependents). US, EU, and UN Citizens are becoming the whores of the wealthy fucked now, beaten later, and screwed to death.
/. Readers and US Citizens. Try to get a politician, CEO, holy-man, or manager to admit they made a mistake, like in this X-43A case.
Failures in business and government projects are due to piss poor performance by management and Bosses not the worker-bees and pack-mules employees. Ecology, business, and tax laws, pension and health benefits,
2001/09/11 NSA, CIA, and FBI failures were not because of the field agents. Two Shuttle disasters, Hubble Telescope, X-43A,
Politicians of the Capitalist Republic applaud CEOs' and staffs' performance in saving the economy by getting the worker-bees and pack-mules (US Citizens) to pay for the bad global economy. The President after 2001/09/11 called for all good US Citizens to spend our money and support the USA. The CEOs', staffs', and politicians (have a different agenda) are setting up more corporate and wealthy tax welfare programs for the oil and construction companies in Iraq and national parks, pharmaceutical companies in Africa,
US Citizens will pay in the future (our children, grandchildren,
OldHawk777
Reality is a self-induced hallucination.
Yea, I know, I did stray a little from topic, but I beg forgiveness from
Unaccountable leaders are masters, and unrepresented people are slaves. How do US and EU fare?
Actually, if you stop and think about you'll realize that the way NASA put men on the moon was very much in line with the FBC philosophy. Rather than investing a huge amount of money in something complex and "high-tech" like the X-20 DynaSoar and taking forever to develop the missions NASA operated on a fixed, very tight schedule (land and return before the decade is out), and opted for simple, rugged solutions. Sounds a lot like the mandated "3 years from 0 to launch" policy and deliberate selection of less complex solutions to me that APL used for NEAR and other FBC missions. Sure, the NASA lunar program to develop a lot of new technology, but the underlying philosophy very much FBC. FBC doesn't mean spending less money, and it doesn't mean doing a bad job. It means thinking about what you are doing, and trying to maximize the value for the money you are spending.
We don't need a good return on investment -- we need more investment. NASA's annual budget is less than we are spending every two months occupying Iraq. In the mid-60's, NASA received about 5% of the total federal budget. Now it gets less than 1/2%. We need a President like Kennedy again -- one who values space exploration more than oil exploitation.
Presidential politics have very little to do with it. While I agree that Kennedy was extremely inspiring, I think he was dealing with a very different environment than we face today. What we really need is for the federal government to get its nose out of space, and to back off on the various regulations that mke it hard for commercial interests to do anything in space. The American public (as a whole) apparently doesn't care about space. If they did, it would be a great campaign platform, and someone would use it as such. The "public" doesn't want to spend the money, they have no tolerance for failure, and all they are interested in is spectacular firsts. This attitude is not conducive to a healthy space program. When you add in the fact that NASA is now a bloated bureaucracy, riddled with incompetent engineers and managers, drowning in unwanted congressional pork, and essentially wedded by politics to a launch system that is clearly over-priced and broken, it's no surprise that our space program is a mess.
What we really need is for the federal government to get its nose out of space, and to back off on the various regulations that mke it hard for commercial interests to do anything in space.
Businesses want profits and the profits just aren't there for pure science research in space. Universities won't be funding space exploration -- it's often tough for them to find enough money in the budget for facilities maintenance. Boeing is not going to land a man on Mars in the hopes that they will be able to turn a profit from the mission. Lockheed is not going to fund the launch of a next-generation space telescope with the expectation of making money from the venture.
I just don't believe that it would further our knowledge, increase our enthusiasm, or make us proud to be Americans if some private firm launched Lance Bass (of 'N Sync), Dennis Tito, and other multi-millionaire space-tourist-wannabes into orbit.
The private sector will continue to fund and launch communications satellites -- and will do little else. Nothing else having to do with space has been shown to have any real promise of generating a positive cash flow.
The American public (as a whole) apparently doesn't care about space. If they did, it would be a great campaign platform, and someone would use it as such. The "public" doesn't want to spend the money, they have no tolerance for failure, and all they are interested in is spectacular firsts.
Most of the public doesn't care about physical fitness either, but that does not mean that the The Presidents Council on Physical Fitness and Sports should be eliminated. Sometimes it's important for leaders to lead, to set goals, and to energize the public to achieve those goals. That's what Kennedy did and that's what we need now. There is more to being a leader than creating budgets and priorities based on opinion polls and focus groups. A President's job is to look out for the good of the country, not pander to trailer park inbreds who think that astrology and astronomy are the same thing.
I haven't seen that particular report, but just to clarify what I know, the failure wasn't in the X-43 hypersonic vehicle but in the Pegasus launch booster, built by Orbital Sciences. Apparently the Pegasus was built to be launched at 40,000 feet, however in the first test it was launched at 20,000 feet. The increased air density and aerodynamic loading at this altitude caused a structural failure in a stabilising fin on the booster, not the X-43 craft itself, which remains unproven.