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)."

Comments

Imagine if NASA spent some of their cash on this

[joshv]

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.

What about airships?

[Jon Chatow]

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...

Re:do the math.

[FTL]

> In any case the energy savings by lifting the payload to 20km are minimal at best. Most of the advantage comes from being weather independant, due to being above the clouds.

Nice point. However, I'd think that there are more important saveings than a 20km lift and weather independance:

• Equator. You get to launch exactly on the equator, instead of having to burn fuel in dog-leg maneuvers to get there.
• Horizontal speed. An old German V2 can get to space, but it can't get to orbit. A launch is a little bit of up, and a whole lot of sideways. If you dump the rocket out of the plane while traveling at Mach 0.75, that's 3% of your velocity taken care of.
• Engines. The real reason rockets stage is to swap out engine nozels. The bells that work at sealevel are ill-suited to vacuum operation. By launching above most of the atmosphere you can just use a single stage.
• Friction. A good portion (numbers anyone?) of the energy of a lunch is devoted to plowing through the air. Something that's not an issue when you start 20km up.