17 February 2014
The Defense Advanced Research Projects Agency (DARPA) plans to award the first design contracts for the vehicle project - known as Experimental Spaceplane, or XS-1- in May or thereabouts, officials said. Current schedules call for the vessel to get off the ground for the first time in late 2017 and make an orbital test flight the following year.
DARPA has high expectations for the XS-1 program, which it hopes can eventually launch 3,000- to 5,000-lb (1,361 to 2,268 kilograms) payloads to orbit for less than $5 million per flight - and to do it at least 10 times per year.
Current space launch vehicles are very expensive, have no surge capability and must be contracted years in advance. For example, the US Air Force's Evolved Expendable Launch Vehicle (EELV) and Minotaur IV launch vehicles have dramatically increased in cost since the inception of the programs.
In an era of declining budgets and proliferating foreign threats to US air and space assets the need for responsive, affordable access to space is increasingly critical.
"The vision here is to break the cycle of escalating space system costs, enable routine space access and hypersonic vehicles," XS-1 program manager Jess Sponable said Feb. 5 during a presentation with NASA's Future In-Space Operations (FISO) working group.
DARPA first announced the ambitious XS-1 program last September. It's viewed as complementary to another agency effort known as ALASA (Airborne Launch Assist Space Access), which seeks to launch 100-lb (45 kg) satellites to orbit for less than $1 million apiece using traditional airplanes outfitted with expendable upper stages.
The vehicle developed in the XS-1 program could eventually transition to the commercial market, greatly reducing launch costs for many customers around the world, Sponable said. And the space plane could have many other applications as well.
The XS-1 program represents a return to the bold aerospace projects of decades past, when engineers from various government agencies came together to push the spaceflight envelope, Sponable said.
"We stopped when we flew the X-15 back in the '60s; we didn't do anything
else," he said.