Boeing has been selected by the U.S. Defense Advanced Research Projects Agency (DARPA) to design, build, and test a technology demonstration vehicle, called Phantom Express, for Phase II of the Experimental Spaceplane (XS-1) program.

The XS-1 project dates back to 2013, when DARPA announced a plan to work with private industry to design, develop, build, and eventually commercialize a reusable spaceplane. The project grew out of the recognition at DARPA of the need for a reusable spaceplane that could launch small satellites on short notice at low cost.

During Phase I of the program, program participants designed a demonstrator spacecraft, conducted risk reduction on core technologies and processes, and developed a plan for maturing the technologies. Teams involved in Phase I included Boeing and Blue Origin, Masten Space Systems and XCOR Aerospace, and Northrop Grumman, Virgin Galactic, and Scaled Composites.

DARPA announced the start of Phase II of the project in April 2016. According to DARPA, the XS-1 program envisions a fully reusable autonomous vehicle, roughly the size of a business jet, which would take off vertically like a rocket and fly to hypersonic speeds. The vehicle would be launched with no external boosters, powered solely by self-contained cryogenic propellants. Upon reaching a high suborbital altitude, the booster would release an expendable upper stage able to deploy a 1,360-kilogram (3,000-pound) satellite to polar orbit for $5 million or less per launch. As part of the development program, DARPA intends to launch the XS-1 10 times in 10 days to demonstrate rapid launch capability.

While Boeing worked with Blue Origin on Phase I of the program, the Chicago-based aerospace giant switched to Aerojet Rocketdyne to power its XS-1 vehicle for Phase II. The engines provided by Aerojet Rocketdyne will be designated AR-22 and will be assembled from parts that remained in both Aerojet Rocketdyne and NASA inventories from early versions of the SSME engines. Assembly and ground testing will take place at NASA’s Stennis Space Center in Mississippi.

Being able to launch 1,360 kilogram payloads to low Earth orbit for $5 million on a reusable spaceplane could drastically change the market dynamics of the launch industry. If successful, the spaceplane will benefit in the commercial market from the growing popularity of small satellites deployed in low Earth orbits.