Interesting. DARPA projects have a way of coming true.
“Key XS-1 technical goals include flying 10 times in 10 days, achieving speeds of Mach 10+ at least once and launching a representative payload to orbit. The program also seeks to reduce the cost of access to space for small (3,000- to 5,000-pound) payloads by at least a factor of 10, to less than $5 million per flight. “
What is most intriguing to me is that we know have Elon Musk’s SpaceX working on a reusable rocket. DARPA. The British SABRE project. We have three private space companies working with NASA’s commercial crew transport program (SpaceX, Orbital, and DreamChaser).
There’s a lot of concurrent activity going on. Which is encouraging.