Currently, launching satellites is an involved and expensive process. DARPA’s Experimental Spaceplane (XS-1) program hopes to make this a thing of the past, by developing a shuttle-like resuable launch system that can turn around from landing to relaunch in one day, and bring down the cost of launching by a factor of 10.
We live in a fast-paced world where international situations can change overnight. Areas that were once stable and peaceful can suddenly turn into hotbeds of war and crisis. To deal with these security threats, the United States relies, in part, on its fleet of military surveillance satellites. Unfortunately, whereas a threat can pop up suddenly, satellites can only be launched from a handful of locations, plus they require the logistics of a small war to launch, and take years and hundreds of millions of dollars to put into orbit. This makes putting assets in space on short notice a herculean task.
To cut down on these problems, DARPA started its XS-1 program, aimed at developing a new breed of spaceplane. The agency envisions this as a modular craft with automatic launch, flight, and recovery systems based on off-the-shelf technologies, yet one that would be capable of taking off from a "clean" pad. That is, one that doesn't have much more infrastructure or crew than would be needed to put a conventional transport plane in the air.
The XS-1 is nothing if not ambitious. DARPA wants the spaceplane to be able to launch 10 times over a 10-day period, fly in a suborbital trajectory at speeds in excess of Mach 10, release a satellite launch vehicle while in flight, and reduce the cost of putting a 3,000 to 5,000 lb (1,360 to 2,267 kg) payload into orbit to US$5 million.
"XS-1 aims to help break the cycle of launches happening farther and farther apart and costing more and more," says Jess Sponable, DARPA program manager heading XS-1. "It would also help further our progress toward practical hypersonic aircraft technologies and increase opportunities to test new satellite technologies as well."
DARPA is currently soliciting ideas and technical proposals for the project with an XS-1 Proposers’ Day scheduled for October 7.
"We want to build off of proven technologies to create a reliable, cost-effective space delivery system with one-day turnaround," says Sponable. "How it’s configured, how it gets up and how it gets back are pretty much all on the table – we’re looking for the most creative yet practical solutions possible."
Source: DARPA
http://en.wikipedia.org/wiki/Black_Horse_%28spacecraft%29
I wonder if Mitchell Burnside Clapp is associated with this instantiation of the small military space plane?
He certainly is at DAPA now... http://www.darpa.mil/Our_Work/TTO/Personnel/Mr__Mitchell_Burnside_Clapp.aspx
And working on Space Launch cost mitigation... http://www.darpa.mil/Our_Work/TTO/Programs/Airborne_Launch_Assist_Space_Access_%28ALASA%29.aspx
The biggest hurdle hasn't been the tech of engines, it has been HEAT. At those speeds the friction from the air heats up the outside of the aircraft and all of it's engine components as well. So, if you solve the heat problem, then you can build yourself a scramjet aircraft.
While I realize it's not the actual definition of insanity repeating the same thing over and over and expecting a different result each time isn't real smart.
Besides this thing isn't going orbital velocities, only mach 10 ;)