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Launching Spacecraft From Aircraft
Embedded Geek writes: "New Scientist has an article on a proposed launch scheme named 'Bladerunner' (presumably, someone is a P.K. Dick fan) that would
use a pneumatic launcher to shove a launch vehicle out the back of a military transport aircraft at high altitude (40,000 feet/12,000 meters). As with all the new systems (such as this one) the goal is to reduce launch costs to more reasonable levels (to about $6K/kilo from today's $11-44K). An existing Pegasus system uses dedicated B-52s with the vehicle slung underneath, but Bladerunner would be an improvement by not requiring dedicated planes (the launcher could be set up on a transport in 24 hours) and also could accomodate larger vehicles (since it wouldn't be slung underneath)."
According to the Pegasus link in the submission, the Pegasus system uses a modified Lockheed L-1011 airliner jet named Stargazer, not B-52s. Methinks someone has overdosed on CNN again...
Money for nothing, pix for free
Instead of on massive boondoggles like the ISS. What people don't seem to get is that it all comes down to price per kilo to orbit - if we can't get that price down we are never going to have a sustainable presence in space.
NASA has absolutely no incentive to reasearch alternative (and cheaper) launch methodologies because they are politically committed to the space shuttle (another massive boondoggle).
I say we tell NASA they can keep the ISS, if and only if they can produce a launch vehicle which is capable of sending a thousand pound payload into orbit for 1/10th the current cost. Then we might see some progress on this front.
IIRC, airships are much cheaper per kilo than other aircraft, so surely they would be more suitable for slinging great big pneumatic guns on if you're going for the ultimate cheap solution? Of course, airships are quite slow, but they can carry heavy loads - e.g. the CargoLifter, mentioned here.
Of course, a space-lift would be both much cooler, and much cheaper (ISTR figures of $210 per human for an up-trip, or $40 for a round trip, as on the way down your delta-GPE could be converted back into electricity; presumably this is ignoring R&D and build costs). NASA was mumbling about this about a year ago, but surely such a project would cost billions (and with the US governmental system, it probably won't happen unless a forthcoming, insightful (gasp!) President decides it's important for the future of the US, and can convert/convince a whole lot of people...
James F.
The term "Bladerunner" is imho not a P.K.Dick-Term. The Story is entitled "Do Androids Dream Of Electric Sheep", the title "Bladerunner" was first used in the movie by R. Scott.
Can anyboy enlighten me where it is from?
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Could be worse. Could be raining.
The US Military (who else?) tried this in the '60s with Minuteman ICBMs. Except they used a C5 Galaxy transport and a parachute. I believe the few tests worked well enough, but it was never adopted as an operational launch method: to be effective for nuclear deterrent would have required a fleet of C5s (only ~50 were built and they were built for heavy airlift), continuously airborne. Turns out to be cheaper to stick the Minutemans on the back of a train and drive it around the country (who'd a thunk?).
Anyway, as a commercial enterprise for smallsat launches, this would appear to be a workable solution - use a ram instead of expensive parachutes, and fly the transport down to the equator before launch (same trick that SeaLaunch uses). I just hope the launch vehicle is a bit more reliable than the competitor - Pegasus. They've had a bit of a run of bad luck recently...
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I'd rather have a bottle in front of me than a frontal lobotomy
The space shuttle originally was supposed to operate this way, with one plane carrying the spacecraft part to high altitude and then rocketing from there. It was rejected because it required developing a big plane as well as the shuttle. This method may be an improvement over that proposal.
So long and thanks for all the fish . . . !!!
Price per kilo to orbit is NOT the only hurdle! I can see three major obstacles off the top of my head:
No Funding: Who in this age of recession is foolhardy enough to finance such a venture after all the venture capital firms got burned in last years crash?
Payload design: Modern satellites are custom designed to match their launchers. Diameter, mass, etc are optimized during the design stages to the specifications of the intended launcher. Who exactly is going to redesign their multi-million dollar satellites for the unique constraints used in this design?
Market: Who will be buying? Any air lauched design is going to be limited by the launch aircraft, in Pegasus's (L1011) case by aircraft's undercarriage, and in Bladerunner's (Which aircraft? C131/C5/C17's? Good luck in convincing the USAF to lend you one, they are waaay overtasked already.) by cargo bay weight constraints. Since Iridium chapter 11'ed the market for lightweight sats in LEO has almost completely evaporated.
Democracy is a sheep and two wolves deciding what to have for lunch. Freedom is a well armed sheep contesting the issue
The test firing (it was about this time last year I think) must have been important because all sorts of VIPs from NASA and the Air Force showed up, which didn't normally happen.
I've said it before and I'll say it again: Test firings are cool! The shockwave hitting you is really a unique experience.
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Another idea along this line is the joint MIT / US Air Force project called Black Horse. The key idea behind the Black Horse is that it can be aerially `refueled' from a tanker such as the USAF KC-135. This has caused some people to describe it as `stage-and-a-half' rather than a true SSTO vehicle. It will take off and land horizontally from a runway, and will be piloted by human pilots. Two demonstration vehicles were planned as stepping stones to the Black Horse, called the Black Foal and the Black Colt. The Foal would demonstrate aspects of the technology and provide proof of concept. The Colt would fly to half orbital velocity and utilize an off-the-shelf `kick-stage' to put satellites in orbit.
Of course, a space-lift would be both much cooler, and much cheaper (ISTR figures of $210 per human for an up-trip, or $40 for a round trip, as on the way down your delta-GPE could be converted back into electricity; presumably this is ignoring R&D and build costs). NASA was mumbling about this about a year ago, but surely such a project would cost billions...
If you mean a space elevator as in "Red Mars" or that Arthur C. Clarke book, it'd cost a lot more than "billions", unless you mean "1000's of billions" by that. I don't think there's any material yet developed that could accomodate the engineering demands of such a project, and is available in such massive quantities. Plus all the orbital infrastructure needed to build the sucker, and all the spacecraft needed to transport things to orbit, and/or mine asteroids for raw materials. A vast undertaking, to say the least. Needless to say, it WOULD be the most economical way to reach orbit, on a per-kilo basis. Human society would be revolutionized - I hope to see such a project given serious consideration within my lifetime, but I suspect the political will to do so is lacking.
Freedom: "I won't!"
Half true. The shuttle is a huge political stone around NASA's neck, but there is still a strong desire in most of the agency to get launch costs down and reliability up.
The simple reality of the situation is that rocketry is hard. Here's a partial list of commercial enterprises trying to get in on it:
And of course the big boys like Boeing, Lock-Mart, and all the various non-Amurrican folks like Russia, China, Japan, and the EU.
Any of these enterprises would be, er, on top of the world if they could develop a low cost launch vehicle. It's much easier to grumble about how expensive access to space is than it is to actually do something about it. Whether NASA is going about it in a sensible way is a separate question, but it's not like all they're just sitting on their duffs waiting for the right incentive.
Nice point. However, I'd think that there are more important saveings than a 20km lift and weather independance:
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Most of the fuel use by a modern rocket occurs just getting off the launch pad. Current launch systems work by placing the rocket in a vertical position on the launch pad before liftoff, and the rocket lifts straight up before performing what's called a "roll maneuver" (this is unmistakable on the Space Shuttle, but "regular" cylindrical rockets do it as well) to get into the correct attitude for the rest of the flight. This is an incredibly energy-inefficient method, but the rockets are designed to work this way.
Consider also that most launches take place from sea level (the Sea Launch converted oil platform is a perfect example) where the earth's atmosphere is thickest, causing a lot of reistance that has to be overcome by the force of the rocket motors. At 40,000 feet, the atmosphere is far thinner (consider that humans have to wear breathing masks above 10,000) so there's less fuel used just burning through the lower atmosphere.
There is also a velocity bonus that comes from launching this way. A rocket lifting off from the earth's surface is only getting a "free" boost from the speed at which the ground moves at that latitude, explaining why the equator is the best latitude for launches and why Sea Launch tries to get as close to it as possible. An air-launched rocket like Pegasus gets the "free" velocity bonus from the launching aircraft in addition to that from the earth's rotation.
So... let the aircraft, which costs far far less to operate (we don't have rockets in every garage, but I know a few pilots) do most of the hard work and then let the rocket literally piggyback on that. (Yes, I know full well that Pegasus rides under the L-1011!)
i am a soviet space shuttle
That's Buran, the Soviet space shuttle. This photo is showing the Russian/Soviet equivalent of the U.S. Shuttle Carrier Aircraft. I do believe the An-225 might have been custom-developed for this purpose, an extremely expensive proposition. The United States, on the other hand, transports the shuttle orbiters on a widely-available commercial aircraft -- in fact, the early photographs of the SCA clearly reveal American Airlines markings faintly visible on the skin of the plane! (Both 747s have since been repainted white with a blue stripe.)
They are not stock, though:
Modifications to tail to counter increased wake turbulence from Orbiter
SCA without orbiter, displaying attachment fittings like those on External Tank
SCA carrying orbiter Enterprise about to land
N905NA served with American until 1974. The other, N911NA, is from Japan Air Lines and was acquired by NASA in 1988.
I've got pictures of one of the Buran test articles if you're wondering how this Soviet version of the Space Shuttle looks from up close.
i am a soviet space shuttle
Slashdot has reported on the Canadian entry into the XPrize contest. The DeVinci project intends to raise there rocket to high altitudes via baloon and launch from there. Perfect example of the KISS principle well applied.
Good Luck to them.
- When a rocket takes off from the ground, it is throwing away gas at many times the speed of sound while it's moving very slowly. If you calculate the amount of energy which actually accrues to the rocket versus what disappears as heat and noise with the exhaust gas, the efficiency is dismal. Launching from an aircraft allows the rocket to begin operating at a much higher efficiency; indeed, the air-launched rocket starts at a speed and altitude that the ground-launched rocket may have to burn half of its mass to reach.
- Nozzles cost about the same, but a nozzle with a bigger bell can expand the gases more and get more thrust out of them. More thrust for the same fuel means more payload to orbit, and costs go down. You can't use a large-bell nozzle on a launch from the ground because the gases would be over-expanded, separate from the nozzle walls and cost you badly in efficiency and thrust. This means that the rocket launching from high altitude has an advantage which goes well beyond starting a bit higher.
- The payload at the end of a rocket burn is an exponential function of the delta-V (the more speed you have to put on, the more of your vehicle has to be fuel and the less is payload); getting a 550-600 MPH or so head-start helps a lot. So does the aerodynamic lift of the wing, which is effectively "vertical thrust" that comes for a fraction of the fuel required to produce the same with rocket fuel.
Hope that helped.Scientists restrict study to entire physical universe; creationist