SpaceShipOne Flight Not as Perfect as it Seemed 609
ArbiterOne writes "SpaceShipOne's flight wasn't as perfect as it seemed, according to Burt Rutan and New Scientist. Apparently, at one point in the descent, the pilot completely lost attitude control. According to him, "If that had happened earlier, I would never have made it and you all would be looking sad right now." Could this pose some problems for the X-Prize contender?"
Re:Engine cowling (Score:1, Informative)
uhh... HELLO! (Score:1, Informative)
Re:Attitude? (Score:5, Informative)
Re:Attitude? (Score:5, Informative)
Uh... I would hope they have control over the plane's attitude.
Main Entry: at-ti-tude
5 : the position of an aircraft or spacecraft determined by the relationship between its axes and a reference datum (as the horizon or a particular star)
For all the Attitude Jokes.... (Score:3, Informative)
"The position in space of a spacecraft or aircraft. A satellite's attitude can be measured by the angle the satellite makes with the object it is orbiting, usually the Earth. Attitude determines the direction a satellite's instruments face. The attitude of a satellite must be constantly maintained; this is known as attitude control."
You're welcome.
Re:attitude control (Score:3, Informative)
Re:Attitude? (Score:2, Informative)
Re:So ? (Score:1, Informative)
Maybe he and his boss Rutan are concerned about the public getting excited about jumping into a tin can which only through sheer coincidence did not kill the test pilot?
This announcement means as much to me as the flight itself, and paradoxically lends support to those comments in the voting area about Scaled Composites being trustworthy enough to warrant flying their craft.
Re:This isn't what I expected (Score:2, Informative)
going around the world on a raft is a contest for amateurs, going into space is a job for Hobbyists, which aren't necessarily doing it for free, only for fun. ANd Paul allen is by definition is an ameteur since he's never funded space exploration before.
Re:It should have been expected (Score:5, Informative)
SpaceShipOne does indeed have cold gas attitude thrusters. You can see a photo of one firing during a test flight here [scaled.com].
Ascent phase, not descent (Score:4, Informative)
Dictionnary to the rescue (Score:5, Informative)
Re:Still 62% willing to fly? (Score:5, Informative)
Re:It should have been expected (Score:5, Informative)
Once you are in space your inertia will carry you along what ever path you started. So if you start in the proper attitude, and under control, you'll return to the atmosphere in much the same condition. If you leave the atmosphere tumbling out of control, you'll hit it out of control and you'll be far less likely to ever regain it. Indeed, at that air speed, as you drop you into thicker air out of control you are far more likely to suffer complete structural failure. That's bad.
False info - it was during ascent, not descent (Score:1, Informative)
Re:His view... (Score:2, Informative)
Obligatory Simpsons quote:
I for one welcome our new M&M overlords!
As they say... (Score:2, Informative)
Any landing you can walk away from is a good one!
The Right Stuff (Score:5, Informative)
And yes, Chuck Yeager (IMHO) was the greatest. The book reminds us of the distinction between real pilots and astronauts (mostly passengers). The guy who piloted Richard Noble's Thrust (supersonic on land) and the guy who piloted the Rutan craft are pilots.
Re:Amateurs (Score:3, Informative)
You don't perhaps think that FL 600 means 600,000 feet (or meters, or whatever), do you? It is 60,000 feet.
Fixing tumbling not as easy as it seems... (Score:5, Informative)
wrong.
Most objects do not spin cleanly about most axes. Rigid bodies (such as books, spaceships, rocks, lollipops, and bullets) have three "principal axes" that pass through the center of gravity and are determined by the mass distribution in the object. There's a "minimum" axis that minimizes the kinetic energy for a given angular momentum -- that's the axis around which the thing is the most clustered. For a screwdriver, the minimum axis generally points down the length of the scredriver shaft. There's also a "maximum" axis around which the thing is the most spread out of any direction. For a flat object like a book or a pancake, the maximum axis points directly out of the flat face. Those are the only two axes around which you can spin the object and have it stay stable.
Any other direction will give rise to precession and tumbling, even in vacuum! You can try it with a book -- most closed hardback books have the minimum axis pointing up through the top of the middle pages, and the maximum axis pointing out through the front of the cover. The third dimension -- pointing out through the spine -- is not stable. Tape a book shut and flip it in the air: if you flip it around the maximum or minimum moment axis it will do what you think -- just flip over before you catch it again. If you flip it around the intermediate axis (by, say, starting with the book facing you right-side up with the spine on the left, and pulling the bottom edge toward you as you throw it up in the air) then you might expect the spine to stay on your left side -- but it will flip back and forth, often ending up on your right side, as the book tumbles in the air. (Remember to tape the book closed before tossing it!).
Anyhow, that's a problem for stopping spin and tumbling, because it's not always obvious which way to fire the cold-gas jets to slow down your rotation: by the time you actually fire them you might have tumbled around so that they are speeding you up instead of slowing you down.
I guess that's why "carefree re-entry" is such a great feature of SpaceShipOne -- it's remarkable that they were able to land safely even without good attitude control at apogee.
This isn't really news if you RTFAd yesterday. (Score:5, Informative)
There was a show recently on PBS about the Joint Strike Fighter selection competition. The first flights of the aircraft were done with the landing gear down because with all the other uncertainties they didn't want to take the chance that the gear would fail to lower. They had glitches with hydraulic leaks, landing gear brakes, the VTOL systems, and refueling equipment. In any kind of new aircraft, you expect there to be lots of little problems, more than a few of which are capable of killing the test pilots.
Rutan doesn't seem to be taking any unnecessary chances; he's taking this step by step. If he was just rushing break-neck to win, he'd be going for the prize today. We don't know at this point how much of a setback these glitches were, but I'm reasonably sure he has time for dealing with them charted out in the project.
Yeager (Score:5, Informative)
Re:For all the Attitude Jokes.... (Score:5, Informative)
Re:Challenger reference? (Score:5, Informative)
Say what you will about Reagan, regardless of how you felt about his policies (many were quite controversial), he sure could deliver great speeches.
The best lines in it, however, were paraphrased from John Gillespie McGee's famous poem "High Flight" [af.mil], which is also what Melvill was most likely thinking of. It's a standard reading at the funerals of pilots, and I personally feel that Reagan's speech would have been better, and perhaps more fitting, had he finished with the entire poem. It sums up the main reason why astronauts - military, governmental or private - will always want to strap themselves into something that will never be 100% safe and fly.
Re:This isn't what I expected (Score:4, Informative)
This is about what it costs to fly a 747 across the country.
thad
Re:they will win (Score:4, Informative)
Re:This isn't what I expected (Score:2, Informative)
The last shuttle, Endeavor, completed in May 1991, cost $2.1 billion and was designed to be used for 100 trips (which divides out to $21 million per trip). This winds up being a rather minor part (7%) of the total cost of a space shuttle launch, estimated to be $300 million per launch for the first eight flights in any given year (through the year 2020). (taken from http://www.distant-star.com/issue13/april_2003_sp
Re:This is why more people didnt go (Score:2, Informative)
The space station is orbiting at 360 km right now. Does that mean it isn't in LEO either?
Weightless.... (Score:3, Informative)
He became "weightless" the instant he cut the thrust, because then the only acceleration acting on the aircraft was gravity. I.e., he still had weight, but he was unable to feel it, because he was coasting freely along with it.
Oops, fulll project (Score:2, Informative)
SP
Re:Yeager (Score:4, Informative)
And Gus didn't just have a problem with Liberty Bell 7's hatch, if memory serves he had a big problem with the one on Apollo 1 as well.
Re:Who's cleaning up the M&Ms? (Score:3, Informative)
Re:Amateurs (Score:3, Informative)
You appear to think that the X Prize has been put up by the government.
This is not correct.
The X Prize is completely private. Peter Diamantes has raised several million dollars from private donations. This has then been used to pay the premium on an insurance policy, with the insurance company essentially betting that the X Prize will not be won before the end of this year, and Diamantes (and the competitors) betting that it will be.
The government is not involved in any way other than in getting out of the way (which the FAA is doing a pretty good job of -- a year ago there was no legal way to make a flight such as yesterdays one).
Re:Can anyone explain this? (Score:2, Informative)
Re:Fixing tumbling not as easy as it seems... (Score:3, Informative)
Low-Earth orbit is close enough to Earth's surface that you are "at the top of a parabolic trajectory" (actually, in an elliptical trajectory) all the time -- accelerating toward Earth's surface at like 0.99 gee.
Earth's field only gets negligible at distances of about a million miles -- that far out, the Sun's field dominates the local gravitational environment.
Re:minor setbacks and some carmack links :P (Score:3, Informative)
How many times do we have to hear this? I've cited this article on Slashdot before, and if necessary I will cite it again. Steven Kelman explained it in Government Excecutive magazine, back in 1998 [govexec.com].
Mind you I don't disagree with you on the issue of those school boards getting screwed on wireless networking equipment...the point is that sometimes the accounting is unintentionally misleading, and these sorts of numbers don't necessarily always represent waste or fraud.Missed the launch coverage? Problem not (Score:1, Informative)
Dictionary missed yaw. (Score:4, Informative)
Nose-uppy/nose-downy (ptich), wingtip-uppy/wingtip-downy (roll).
But (unless I misunderstand the term and it's specificially excluded) the dictionary missed yaw: Nose-righty/nose-lefty.
An aircraft's position at any instant has six degrees of freedom: Three of attitude (roll, pitch, and yaw), three of location.
Additionally there are the deriviatives of each of those (i.e. position gives three each of velocity, accelleration, jerk, snap, etc., attitude gives roll/pitch/yaw rates, etc.)
Re:Nice to see them so honest (Score:3, Informative)
Re:This isn't what I expected (Score:3, Informative)
From here [armadilloaerospace.com]:
They managed a total of 12 launches, with the final (NASA-run) one resulting in destruction of the vehicle due to mistakes made by the ground crew which prevented one of the landing legs from deploying correctly.The "official" blame for killing DC-X was that they couldn't build a composite fiber fuel tank big enough, but the real problem was the $billions that Boeing and Lockheed (or Rockwell, at the time) would have lost in support contracts for the Space Shuttle, which probably weighed heavily on the consciences of some Alabama, Washington and Florida congress critters also.
You are here confusing the X-33 program, which was run by NASA and built by Lockheed, with the DC-X program. DC-X died because NASA didn't like it. The X-33 program was indeed killed partly as a result of their inability to build a "conformal" composite propellant tank, as well as severe cost over-runs and a growing realization that it would never carry any significant payload. However, the X-33 design was significantly different than the DC-X/Delta Clipper design, and in many ways pushed the technological envelope much further (which was a major cause of their later over-runs). Why NASA picked the Lockheed design (which was essentially just some marketing material at that point) over the Delta Clipper (which had flight-tested actual hardware) as the winner of the X-33 contract has always been a mystery to me.
Re:This is why more people didnt go (Score:1, Informative)
NASA doesn't award Astronaut status until 50 miles. So it's possible to not enter space, which is defined as 100km(62.1 miles) but still be given the title of Astronaut.
Definitions found here [spacetoday.org]
So what are we going to call these guys, Private Astronauts?
Re:Fixing tumbling not as easy as it seems... (Score:3, Informative)
Not quite. An object like a rectangular block of wood can be spun around any of three axes (the obvious one). A ball can be spun around any axis. A disk can be spun around the axis normal to the surface or any axis parallel to the surface.
I have moment-of-inertia tensors spinning in my head...
Re:Still a great flight (Score:2, Informative)
Re:It should have been expected (Score:3, Informative)
The Mercury spacecraft was designed such that it would naturally orient itself properly. (And on the Shepard and Grissom flights it certainly counted as a 'manned exoatmospheric craft'.)
It's wings that make the need for precise control necessary. Rutan avoids this issue to some extent by aereodynamic tricks.
Not quite right. (Score:3, Informative)
The airspace above FL600 was changed to Class E in 1998. The events of 9/11 had nothing to do with it.
The upper limit of Class E is not "NaN". Class E ends at 100,000m (62 statute miles if you prefer). Above that is "space".
Class E is only controlled airspace where IFR flight is concerned. You don't need an ATC clearance to fly above FL600 if you are operating in accordance with VFR.
Most people assume you can't get to FL600 without passing through Class A. That's only true if you stay within 12 nautical miles of the U.S.A. coastline, as mentioned above. There is some uncontrolled international airspace, or at least there used to be. Of course, you can also get to FL600 via Class F airspace. This would require permission from the agency responsible for that airspace, but wouldn't technically require an IFR clearance.
Re:Still a great flight (Score:5, Informative)
One might also offer that certain Apollo (1) folks might have not wanted their TEST FLIGHT to go deeply wrong.
Rockets are dangerous. Space flight is dangerous. This isn't a run to the 7-11. So far, NASA and the US have been excessively successful in space flight.