November 21, 2013
The U.S. Defense Advanced Research Project Agency’s (Darpa) goal with its new Experimental Spaceplane (XS-1) program is to demonstrate a reusable capability that can transition to industry for low-cost military and commercial satellite launches and hypersonic technology testing.
The agency usually hands off successful programs to one of the U.S. military services, but “Darpa’s XS-1 transition partner is you — industry,” Program Manager Jess Sponable told attendees at a proposers’ day briefing earlier this month.
In addition to enabling lower-cost, more-responsive launches of U.S. government satellites, Darpa sees the reusable first-stage technology to be demonstrated under the XS-1 program as key to recapturing a commercial launch market lost to foreign competitors.
The program’s goal is to fly an X-plane reusable first-stage to demonstrate technology for an operational system capable of launching 3,000-5,000-lb. payloads to low Earth orbit for less than $5 million per flight at a launch rate of 10 or more flights a year.
This compares with around $55 million to launch that class of payload on the Orbital Sciences Minotaur IV expendable booster, which operates at a flight rate of around one a year, according to Darpa’s program presentation.
The agency plans to award three or four $3-4 million Phase 1 preliminary design contracts in the first quarter of 2014, followed a year later by a single design-to-cost contract worth up to $140 million to build and fly an X-plane demonstrator.
If the program proceeds into Phases 2 and 3, first flight is scheduled for the third quarter of 2017, leading to an orbit flight demonstration a year later.
The technical objectives are to fly the XS-1 10 times in 10 days; fly to Mach 10-plus at least once; and launch a demonstration payload into orbit.
The 10 flights in 10 days are intended to demonstrate reusability and expand the flight envelope. There is no velocity requirement for the flights, but the vehicle must take off and land each time.