DARPA XS-1 Space Plane Project Seeks $27 Million in 2015 Funding

Artist's concept of DARPA's Experimental Spaceplane (XS-1), a proposed unmanned, hypersonic vehicle that the agency hopes will lower satellite launch costs substantially. 

Officials are targeting Mach 10 for the suborbital vehicle.

Credit: DARPA

The U.S. Defense Advanced Research Projects Agency expects to spend some $800 million on space programs from 2015 through 2018, an increase of $130 million over what was projected at this time last year, Defense Department budget documents show.

Nearly all of the targeted increase for DARPA's Space Programs and Technology Office is backloaded into the outyears, the documents show.

For 2015, the office is seeking nearly $180 million, only $7.5 million more than this year’s funding level.

DARPA's budget books break out funding on a program-by-program basis for the upcoming fiscal year only; outyear projections are provided only at the department level.

DARPA's mission, generally speaking, is to pursue high-risk, high-payoff technology development projects that could someday benefit the military.

These projects are taken on with the understanding that many, if not most, will fail. Defense Department officials often talk about "DARPA-hard" programs to describe their degree of difficulty.

For example, the 2015 request includes $27 million for XS-1, a concept for a reusable space plane that could ultimately fly 10 times in 10 days and boost payloads into low-Earth orbit for less than $5 million per launch. The program received $10 million in 2014.

"Technologies derived from the XS-1 program will enable routine space launch capabilities with aircraft-like cost, operability and reliability," a DARPA announcement from November 2013 reads.

"The long-term intent is for XS-1 technologies to be transitioned to support not only next-generation launch for Government and commercial customers, but also global reach hypersonic and space access aircraft."

The agency hopes to select a single vendor next year for the final design and development of the vehicle, which could make its initial test flight in 2018.