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Space NASA Science

Air Force Spaceplane Readying For Launch 94

Posted by Soulskill
from the pushing-baby-shuttles-from-the-nest dept.
FleaPlus writes "The US Air Force is currently preparing for the launch of the secretive X-37B OTV-1 (Orbital Test Vehicle 1) spaceplane, which was transferred from NASA to DARPA back in 2004 when NASA opted to focus its budget on lunar exploration. The reusable unmanned spaceplane is set to launch in April on top of a commercial Atlas V rocket, orbit for up to 270 days while testing a number of new technologies, reenter the atmosphere, then land on auto-pilot in California."
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Air Force Spaceplane Readying For Launch

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  • Re:270 days (Score:5, Interesting)

    by khallow (566160) on Sunday March 14, 2010 @10:11AM (#31472204)
    There's a lot of unpleasant stuff you can put in there. My guess is "rods from god", that is, a payload of tungsten or depleted uranium rods that you can drop on a target. If you can get a rod to hit with it's orbital velocity (8 km/s), that would be roughly 7 kilotons (TNT) of energy per kilogram of rod. Halving the velocity of impact (which to me seems achievable and more viable than my first number) would still result in almost 2 kilotons of energy per kg of rod. My view is that this would be more effective than a few nuclear bombs (perhaps the most unpleasant payload you can put in there) since you aren't restricted (ok, less restricted since there's at least one treaty (Outer Space Treaty?)that prohibits any weaponization of space) by treaty, you don't cross an arms-race threshold, and you get similar delivery energies.

    They also can have more flexibility to launch recon and spy technology. Maybe they're looking at retrieving satellites in order to get more data out of them. Remember physically moving data is still the fastest way to move data. You are restricted in how much data you can transfer from space to ground via radio. Maybe they're planning satellites that can generate petabytes or more of data (1,000 terabytes) and return it to Earth. For example, multispectral scans of the Earth at 1 meter resolution. A single byte of information per square meter would be roughly 150 terabytes of data. A single byte of information per 10 cm (decimeter) square would be 15 petabytes of information.

    The vehicle could act as a spy satellite (it could beam some of them down in real time) while archiving everything it sees. The DoD gets both a 270 day satellite with latest technology and a massive, comprehensive archive which it can dig through at its leisure.
  • by wisebabo (638845) on Sunday March 14, 2010 @10:27AM (#31472282) Journal

    While it is nice that this will give the Air Force a means of getting an expensive payload up into orbit and back down again quickly and safely (like onto a runway as opposed to a parachute landing on the ground or at sea) it really doesn't help the overall problem of making access to LEO significantly cheaper. Remember when you're in LEO, you're halfway to anywhere (I forget who said that quote but from the viewpoint of orbital energistics it is true).

    Now that the Obama administration has (hopefully) set us on the right course by FIRST developing the technologies to get us into space, THEN trying to get somewhere, now maybe would be a time to revisit some abandoned ideas. Like the X-34 (I think it was called "Venture Star") using a deltoid lifting body with an aerospike engine it promised to make SSTO (Single Stage to Orbit) possible. Or the "Delta Clipper" a vertical takeoff and vertical landing rocket, I think they got to 1/4 scale.

    While I don't know if the "Delta Clipper" was fatally flawed (I think one of its landing struts collapsed), I heard that the problem with the "Venture Star" was they simply couldn't make the (then) state of the art composite fuel tanks work. So has material science improved enough to make it feasible? Or do we have to wait until "magic" carbon nano-tubes can make eggshells seem like horribly efficient containers?

    An Air Force General once said: "A new plane doesn't make a new engine possible, a new engine makes a new plane possible." That's why the aerospike engine had such promise because it automatically adapted to the changing surrounding air pressure to keep the "nozzle" shape efficient. That (with new and improved) fuel tanks, just might make SSTO possible which, aside from space elevators or air breathing hypersonic space planes, is the only way we'll REALLY bring down the cost of getting into orbit.

  • Re:270 days (Score:2, Interesting)

    by girlintraining (1395911) on Sunday March 14, 2010 @10:29AM (#31472290)

    There's a lot of unpleasant stuff you can put in there. My guess is "rods from god", that is, a payload of tungsten or depleted uranium rods that you can drop on a target.

    Yeah, if we ignore the fact that should something go wrong and the uranium be exposed to plasma during re-entry, we've got a rather large area that's been coated in DU.

    Maybe they're looking at retrieving satellites in order to get more data out of them. Remember physically moving data is still the fastest way to move data. You are restricted in how much data you can transfer from space to ground via radio.

    That might be true enough, but in the 70s they used to drop the film from satellites and then have it caught mid-air by a retrieval aircraft. It's not exactly difficult to build an ejection mechanism into a satellite, or track the return of the package to Earth when you control the initial vector, orbit, and timing. Why expend all that fuel to travel upwards, when you can just drop it?

    For example, multispectral scans of the Earth at 1 meter resolution. A single byte of information per square meter would be roughly 150 terabytes of data. A single byte of information per 10 cm (decimeter) square would be 15 petabytes of information.

    I think optical transmission would be a better way to send that amount of data. The visual spectrum of light is 400-790 THz and the only thing you need to receive the signal is a clear sky. If we're looking at transmitting massive amounts of data in a way that isn't necessarily time-sensitive, I'd suggest optical data transfer. Of course, you have to buffer all that data...

    The DoD gets both a 270 day satellite with latest technology and a massive, comprehensive archive which it can dig through at its leisure.

    The value of most surveillance is directly proportional to how soon it can be retrieved, processed, analyzed, and a decision made and executed based on the analysis via the chain of command. If you know that your high value target, Achmed the Terrorist is going to be visiting a friend's flat at 7:30pm tonight, according to an intercepted cell phone call, but it's in an area with lots of known hostiles, you probably want to recon the area from 7:00--8:00pm using something with enough resolution to be reasonably sure Achmed the Terrorist has shown up at the house, and then maintain that surveillance until a tactical squad can reach the area. LEO vehicles, which is what this is, can have an orbital time of as little as 90 minutes. Yes, you get better resolution on your images, but there's a tradeoff: You don't get as much time over the target.

    If you want a more plausible scenario for the use of this -- inter-satellite communication. You can use a much, much wider band of RF to transmit in space than on the ground, and it goes a lot farther. Ground-based interception of this is, for all intents and purposes, impossible.

  • Re:Cool! (Score:5, Interesting)

    by vlm (69642) on Sunday March 14, 2010 @10:33AM (#31472306)

    The shuttle's promised capability of "bringing cargo back" is a bygone requirement of the days when retrieving a spy satellite was needed to recover the film. How many payloads did the shuttle actually BRING BACK, compared to how many times did it come back with an essentially empty cargo bay, thus purely wasting the space?

    I doubt that you personally inspected the cargo hold after each classified military shuttle mission. Anyway, the wikipedia page you're looking for is:

    http://en.wikipedia.org/wiki/Deterrence_theory [wikipedia.org]

    The situation would imply that, at least in low earth orbit, the USSR was violating some earth orbit treaty, or was planning to do so, and we knew it via some "special means" but needed a public way to wave a geiger counter nearby their satellite to prove it. That, or, we just wanted to shooo them out of low earth orbit.

    A lack of USSR spy satellite launches into low orbit during the shuttle program, is just possibly, a side effect of the existence of the shuttle, not just some random unfortunate unexplainable quantum fluctuation that unfortunately made the shuttle useless, like you seem to imply.

  • Re:270 days (Score:2, Interesting)

    by frieko (855745) on Sunday March 14, 2010 @10:37AM (#31472324)
    Uh, that would be 7 kiloGRAMS, not 7 kilotons. It's far cheaper to just drop 7 kg of TNT out of an airplane.

    http://www.google.com/search?q=%28.5*1kg*%288km%2Fs%29^2%29+%2F+%284.184+gigajoules+%2F+ton%29 [google.com]
  • by speederaser (473477) on Sunday March 14, 2010 @12:19PM (#31473032)

    But a test vehicle for what? What are the ultimate objectives of the program?

    Among other things, it could be used as a platform to carry and move spy satellites. Due to the limited amount of fuel they carry the orbits of spy satellites are predictable and expensive to change. The military could use this as a way to give existing spy satellites greater flexibility on orbit, leaving a satellite in orbit and flying back periodically to refuel, or returning to earth with the satellite and relaunching later. It might even be used to re-direct orbits of existing satellites to extend their useful lifetime.

  • by TwineLogic (1679802) on Sunday March 14, 2010 @12:59PM (#31473292)
    If you check out the photos on Wikipedia of X-37B underneath the Rutan lift vehicle, you can see what looks like a flagpole sticking out of the nose. This spike is retracted at launch and extended prior to re-entry. The purpose of the spike is to create the leading sonic boom (hypersonic bow wave) and transonic region during re-entry -- well in front of the vehicle itself. The atmosphere reaching the wings and thermal protection surfaces is much slower than the hypersonic bow wave -- thus less heating occurs on the fuselage than on the spike.

    The retractable/extensible spike absorbs such an enormous amount of energy and transforms it into heat, yet the spike is not very massive. In order to dissipate the heat without transferring it to the fuselage or melting in an uncontrolled manner, the spike is designed to ablate like many heat shields have (e.g. Apollo). "Ablate" means that the spike flakes apart in a controlled manner which leaves behind useful which continues to be the interface between the craft and the hypersonic flow.

    The spike is shown extended in the re-entry test photo because the vehicle was configured for re-entry.

    Before GWB scuttled Al Gore's X-38 ISS re-entry vehicle, there had been some talk of incorporating the ablative re-entry spike into ISS return craft. It appeared from the outside (I'm not an insider) that the military community in the US was getting paranoid that revealing the secret ablative spike technology to the foreign competition.
  • by moosesocks (264553) on Sunday March 14, 2010 @01:35PM (#31473544) Homepage

    Remember when you're in LEO, you're halfway to anywhere (I forget who said that quote but from the viewpoint of orbital energistics it is true).

    Well, that really depends on where/when you want to go, and whether or not you want to get back. Orbital mechanics is not as simple as escaping earth's gravitational field, and pointing in the right direction.

    Mind you, it *is* a big obstacle that we have yet to overcome effectively, although it's hardly the only one. Think of how massive the Saturn V rockets were in comparison to the tiny spacecraft on top. Heck -- the US still hasn't mastered getting humans into LEO cheaply, safely, or effectively, while the Russians seem to have proved that Soyuz capsules are cheap and indestructible (albeit only good for a single use).

  • Re:Cool! (Score:3, Interesting)

    by zmollusc (763634) on Sunday March 14, 2010 @03:04PM (#31474144)

    Could some clever clogs please calculate the possibility of 24 tonnes of fuel being enough to move the shuttle from its usual LEO to a polar LEO?

  • by geckipede (1261408) on Sunday March 14, 2010 @04:08PM (#31474608)
    I think it's better to think of this thing as being a spy satellite, rather than something used to tend them. It's a spy satellite that can land itself for periodic upgrades, periodic refuels, and which doesn't need to be shunted about because it has its own engine.

    It's also a fair bet that it can carry more than just sensors, but I wouldn't imagine anybody is keen to show off all of its capabilities, so for the forseeable future it'll just be carrying cameras.
  • Re:270 days (Score:3, Interesting)

    by WindBourne (631190) on Sunday March 14, 2010 @07:13PM (#31476190) Journal
    Yes, it would be cheaper. It would also be EASY to pick that up and unable to adjust easily.

    OTH, a SMALL SMALL crowbar sized rod with fins and a chip, will be undetectable. In addition, being able to send them one after another will allow a site to be decimated piece after piece. Such as taking out a nuclear sub base that is buried under ground. Or taking out a nuclear warhead manufacturing site.
  • Soyuz NOT cheap! (Score:3, Interesting)

    by wisebabo (638845) on Monday March 15, 2010 @04:42AM (#31479562) Journal

    Sorry, at $20 million (more now I think) per passenger to orbit, I don't think Soyuz capsules are THAT cheap. We really need one of the technologies discussed before to lower costs a factor of ten (ideally a factor of a hundred).

    I still think just getting to orbit cheaply is THE main hurdle. Once you're there (and again, if getting there is cheap enough so you don't have to sweat every last ounce/gram), there are lots of things you can try. Like VASIMIR or magnetic "bubbles" being pushed by the solar wind (not the same thing as a solar sail) or nuclear thermal. If getting to orbit was cheap enough so you could build life support with 2x (or more) redundancy or just bring up SCUBA tanks maybe it would make designing/building space craft easier. Cheap orbital access? Okay then we can protect ourselves against cosmic rays by shielding our spaceships with WATER (and give the astronauts a really fun zero-g pool to use on the trip).

    Think how much easier space travel would be if the costs were something like that to resupply our base in Antarctica. I mean they have ATMs and (I think) a McDonalds! (Okay I'm dreaming now, maybe that won't come about until we had a space elevator).

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