Soaring Through Space: Spaceplane Enters Phase II

By Marine Cpl Cedric R. Haller II
Defense Media Activity

A long time ago, I used to dream of traveling through outer space to a galaxy far, far away. Well, maybe not that far away, but at least outside of the Earth’s atmosphere. Researchers at the Defense Advanced Research Projects Agency have moved another step in making space-travel a much easier endeavor.


With budgets consistently decreasing and launches generally costing hundreds of millions of dollars each, due to the massive amounts of dedicated infrastructure and large number of personnel required – DARPA created its Experimental Spaceplane program to help overcome these challenges and create a new paradigm for more routine, responsive and affordable space operations, reducing the time to get capabilities to space.

In an important step toward these goals, DARPA has announced Phase 2 of the XS-1 program, which seeks to design and fabricate an experimental unmanned spaceplane using state-of-the-art technologies and streamlined processes, and fly the vehicle 10 times in 10 days. The reusable XS-1 would demonstrate the potential for low-cost and “aircraft-like” high-ops-tempo space flight, enabling a host of critical national security options while helping to launch a new and potentially fruitful commercial sector.

“During Phase 1 of the XS-1 program, the space industry has evolved rapidly and we intend to take advantage of multiple impressive technological and commercial advances,” said Jess Sponable, DARPA program manager. “We intend to leverage those advances along with our Phase 1 progress to break the cycle of escalating DoD space system launch costs, catalyze lower-cost satellite architectures, and prove that routine and responsive access to space can be achieved at costs an order of magnitude lower than with today’s systems.”

The concept for this spaceplane will incorporate a fully reusable unmanned booster vehicle capable of flying at high speeds at a suborbital altitude. At that point, one or more expendable upper stages would separate, boost and deploy a satellite into low Earth orbit, followed by the first stage returning to Earth to be reused for an additional flight. The XS-1 flight booster size, comparable to that of a business jet, would be sufficient to validate credible scaling to larger reusable launch systems. Demonstration of easier access to space, much like aircraft, is important for next-generation DoD needs.

According to DARPA, XS-1 has four primary technical goals:

  • Fly 10 times in a 10-day period (not including weather, range and emergency delays) to demonstrate aircraft-like access to space and eliminate concerns about the cost-effectiveness and reliability of reusable launch.
  • Achieve flight velocity sufficiently high to enable use of a small (and therefore low-cost) expendable upper stage.
  • Launch a 900- to 1,500-pound representative payload to demonstrate an immediate responsive launch capability able to support both DoD and commercial missions. The same XS-1 vehicle could eventually also launch future 3,000+- pound payloads by using a larger expendable upper stage.
  • Reduce the cost of access to space for 3,000+-pound payloads, with a goal of approximately $5 million per flight for the operational system, which would include a reusable booster and expendable upper stage(s).

With technology always moving forward, we just might see the day where commercial space travel is as common as visiting another country.

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