The Defense Advanced Research Projects Agency (DARPA) has initiated a new program, called Experimental Spaceplane 1 (XS-1), to develop a fully reusable unmanned vehicle that would provide aircraft-like access to space.
DARPA is seeking to develop a vehicle that can operate from a “clean pad” with a small ground crew and no need for expensive specialized infrastructure. This setup would enable routine daily operations and flights from a wide range of locations. XS-1 seeks to deploy small satellites faster and more affordably, while demonstrating technology for next-generation space and hypersonic flight for both government and commercial users.
The DARPA program manager for XS-1 is Jess Sponable, who served as DoD program manager for the highly highly successful Delta Clipper Experimental in the 1990’s. Sponable was also one of several Air Force officers selected to train as military spaceflight engineers to fly aboard the Space Shuttle in the 1980’s.
“We want to build off of proven technologies to create a reliable, cost-effective space delivery system with one-day turnaround,” Sponable said. “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.”
DARPA is currently seeking technical proposals and ideas on how to best develop and implement the XS-1 program. The agency has scheduled a Proposers’ Day for October 7, 2013, with 1-on-1 discussions the following day.
XS-1 envisions a reusable first stage that would fly to hypersonic speeds at a suborbital altitude. One or more expendable upper stages would separate to place a satellite into Low Earth Orbit. The reusable first stage would return to earth, land, and be prepared for the next flight. Modular components, durable thermal protection systems and automatic launch, flight, and recovery systems should significantly reduce logistical needs, enabling rapid turnaround between flights.
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.
XS-1 would complement a current DARPA program already researching satellite launch systems that aim to be faster, more convenient and more affordable: Airborne Launch Assist Space Access (ALASA). ALASA seeks to propel 100-pound satellites into orbit for less than $1 million per launch using low-cost, expendable upper stages launched from conventional aircraft.
“XS-1 aims to help break the cycle of launches happening farther and farther apart and costing more and more,” Sponable said. “It would also help further our progress toward practical hypersonic aircraft technologies and increase opportunities to test new satellite technologies as well.”