The Defense Advanced Research Projects Agency (DARPA) has opened its Experimental Spaceplane XS 1 program to proposals for the project’s second and third phase, which include design, fabrication, and finally, the flight test of this remarkable new technology.

The XS 1 requires a design for a reusable booster prototype of a robotic space vehicle that can launch satellites into orbit. The design must be capable of launching a minimum of 3,000 pounds ten times within ten days, and cost no more than $5 million for each launch to the edge of space. That, of course, is no small order.

DARPA states that the objective of XS 1 is to “demonstrate aircraft-like operability, cost efficiency and reliability.”

They add: “In an era of declining budgets and proliferating foreign threats to U.S. air and space assets, routine, affordable and responsive access to space is essential to enabling new military space capabilities and rapid reconstitution of space systems during crisis.”

The deadline for proposals is July 22, with the decision to be announced early in 2017. Interested parties can find more details through the XS 1 project information page.