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SpaceShipOne Back in Action
JoeSilva writes "After a 3 month wait,
Scaled Composites' SpaceShipOne is
back in the skies above Mojave! Not only is it patched up from a failed landing gear, it's got a 'thermal protection system' installed.
Looks like high temp insulation on the leading edges. Also they have a picture of it with 'the rocket motor for the flight 13p'. This was the 12th SpaceShipOne flight."
WOOHOO!!!
Check out the test updates here.
AFAIK, these guys are the closest to winning the X-Prize- go team!!!
Any generalization is a stupid one.
A great set of photos (hopefully soon to be mirrored) is available here.
The X Prize is NOT ABOUT LEO! It's about reaching 100KM, with at least 1 person, in a vehicle capable of carring 3, twice in 2 weeks.
Generally, bash is superior to python in those environments where python is not installed.
now with link and without the added space
i know, i suck at slashdot
Any team wanting to make an attempt must notify the X-Prize officials at least a month in advance with the launch date and location. I would assume that this information would be released with some fanfare. Since no notification has been made yet, no official flight.
That's not to say they couldn't go to space unofficially, before going for the big money; in fact they probably will, as part of their test series.
--riney
If you'd read anything about the X-prize, or even the other posts in this thread, you'd know that the ships are aiming for a sub-orbital flight (for those of you who went to public school, that means they're not coming back from orbit at the end of the flight, either), and therefore no space shuttle-style thermal tiles are required.
The kinetic energy required to accelerate a gallon of gasoline to orbital speed is more than the chemical energy contained in the gasoline.
By contrast, "merely" lifting something up 100km doesn't require much energy at all.
So, er, no, leading-edge heat shields ought to be just fine. Fiberglass or carbon-fiber composites might even survive a flight or two without any shielding at all.
The Space Shuttle comes in a lot faster and through far more atmosphere (Think angle of attack, not just vertical height). These guys are just barely getting out into "space", and aren't anywhere near the altitude or velocity required to get to even low earth orbit, so they don't need much heat shielding at all.
Of course LEO isn't a requirement for the X-prize.
Why yes, I am a rocket scientist.
"Unheard of means only it's undreamed of yet,
Impossible means not yet done." ~~ Julia Ecklar
Dick Rutan did a similar flight with two pilots back in 1986 with Voyager.
:)
Talk about similar designs... Burt Rutan designed Voyager.
11P 17 Dec 03 first powered
10G 4 Dec 03
09G 19-Nov-03
08G 14-Nov-03
Maybe they've updated the page since you looked, but they're all clearly there right now.
Anyways, even at 100km I would think that re-entry like conditions would be encountered and you'd need the high angle of attack.
If you read thier site (after the slashdotting subsides) you will see that the wings fold up 90 degrees during reentry which gives them a very large amount of drag, while maintaining a stable angle of decent.
Most likely they'll hit space with a lone pilot a couple of times first. Ever flight so far only has 2 in the WK and 1 in the SSO. To win the X-Prize they would need 3 people in the SSO. So far they have been playing it safe by only having just as many people as needed(as they should), I don't see any reason they'll change the play. All the test runs they are making is showing the strength of their system, if this were NASA the runs would be 6 months apart. Besides, it's not like there is any other group so close to winning the prize. Maybe some other team might just pop outta nowhere and grab that brass ring, but they would have to be awefully sneaky to do that.
The grass is only greener, if you don't take care of your own lawn.
For the good of the community :)
[...]
Results:
Slashdot's editors are facists.
Launch conditions were 48,500 feet and 125 knots. All systems performed as expected and the vehicle landed successfully while demonstrating the maximum cross wind landing capability.
If it's for the good of the community, then don't put in your personal opinion in the middle of the post.
There may have been more random crap in there, this was the first one I saw. Feel free to remod the karma whore appropriately.
You'd need a lot of heat shielding if you were reentering from orbit, but that's not what this rocket ship is designed to do. It's a suborbital ballistic flight profile, straight up to 60 miles, then freefall back down. Orbital profiles have to go up 200 miles, PLUS they need to have 17,000 MPH of speed to maintain the orbit. The forward momentum of an orbital spacecraft is more energy than the potential energy in 200 miles of altitude.
Spaceship One will only generate temperatures of about 1000 degrees, and since they don't need to use an angle of attack of 40 degrees like the shuttle, they only need to protect the leading edge. The max speed is only about mach 3.5, and the decelleration is 70 seconds. The shuttle on the other hand decellerates from orbital velocity for 20 minutes.
If tits were wings it'd be flying around.
Where do you get that information from? I'm not a physical chemist, but the rocketry books I've read say that chemical fuels aren't going to get much past 450 to 500 seconds Isp. The SSMEs get about 450, I think. Isp (specific impulse) is directly proportional to exhaust temperature, which is always going to be an issue in practical rocket design.
The 1970's NERVA nuclear rocket program managed to get about twice the Isp of our best chemical rockets with a decent amount of thrust. Ion drives might give you an order of magnitude improvement over chemical rockets, but they don't have the thrust to be used in launch vehicles.
The only propulsion system I've seen proposed that could realistically produce 2 to 3 orders of magnitude increase in efficiency is the Orion drive. The government doesn't like the idea of building hundreds of small, clean nukes, though. Greenpeace gets a bit riled up about it, too.
Of course, if I had my way, they'd be welcome to protest right at the launch site.
We also musn't forget the conditons of winning, that the three people who go up in the first flight must do it again in three weeks from the sucessfull landing.
With the results and proof that nothing has knocked SSO out of the contest, I do think that is perfectly possible for them to do this.
NeoThermic
Use my link above, or to view my server, NeoThermic.com
The energy content of gasoline is about 42e6 J/kg.
Orbital velocity (at the surface of the earth) is about 8000 m/s. Kinetic energy of 1 kg at 8000 m/s is 32e6 J. (That is, you need about 32 MJ/kg)
However for those who want the whole story, the parent to this is correct: to get all that energy out of the kg of gasoline, you *also* need about 2.8 kg oxygen. Gasoline-oxygen gets you about 11 MJ/kg, which is about a third of what you need to hit orbital velocity.
To get to 100 km altitude, you need only 0.96 MJ/kg, which is no problem for gasoline-oxygen.
"There are a dozen opinions on a matter until you know the truth. Then there is only one." - CS Lewis (paraprhase)
Yeah, no kidding. Bert Rutan has not one, but 3 aircraft designs displayed at the Smithsonian's National Air and Space Museum. These are the around-the-world Voyager,, and the experimental homebuilts VariEze, and Quickie.
"The plural of anecdote is not data" -- Bruce Schneier
The ship only has to have accomodations for three people. The rules allow for substituting ballast for the passenger's weight and letting the single pilot go up alone. The relevant rule is
According to their flight log: Motor light off was achieved at 44,400 feet and 0.55M. Burnout occurred at 1.2M and apogee was 67,800 feet. The max specs for a 747 are ~45,000 ft. Yes, they've got a bit more to go, but the 67,800 ft was on their first test of the engine. I'm sure they could have let it go longer and easily gotten higher.
You forgot to include the potential energy required to get from earth's surface to orbit.
For LEO (200 km), circular orbit velocity is 7789 m/s. KE is 30.3 MJ. PE for 200 km altitude (from earth's surface to orbit) is 60.7 MJ. If you launch at the equator, prograde, then you gain 464 m/s, for an intial KE of 0.1 MJ.
So total energy required to transport 1 kg to 200 km LEO from stationary at earth's equator, is 90.9 MJ.
Of course, if you're burning the fuel along the way the energy requirement drops as mass decreases, and you also have to add in oxidizer mass, but I don't know the equations for that.
Voyager is at the National Air and Space Museum--hanging from the ceiling. It is a pretty spectacular sight. Here's a link to their article about it, and another to the museum. It's one of the only places I'd ever bother going in Washington D.C....
Actually, Scaled Composites did reveal that it is Paul Allen that is funding it./ Paul%20G%20%20Allen%20and%20SpaceShipOne.pdf
http://scaled.com/projects/tierone/New_Index/news
Do not go gentle into that good night. Rage, rage against the dying of the light.