Launching a satellite into space is a very costly venture. But DARPA hopes to dramatically reduce the costs by building a reusable spaceplane, and they've enlisted Boeing to help.
The XS-1 program hopes to create a fully reusable unmanned aircraft that would send small satellites into orbit. The spaceplane would be able to fly at hypersonic speeds at a suborbital altitude before returning to Earth and preparing for the next flight.
Boeing hopes to produce an aircraft that will be able to fly 10 times a day, achieve speeds greater than mach 10, and reduce the cost of space flights from hundreds of millions of dollars per launch to less than $5 million.