Tag Archives: XS-1

Experimental Spaceplane

DARPA has selected The Boeing Company to complete advanced design work for the Agency’s Experimental Spaceplane (XS-1) program, which aims to build and fly the first of an entirely new class of hypersonic aircraft that would bolster national security by providing short-notice, low-cost access to space. The program aims to achieve a capability well out of reach today – launches to low Earth orbit in days, as compared to the months or years of preparation currently needed to get a single satellite on orbit. Success will depend upon significant advances in both technical capabilities and ground operations, but would revolutionize the Nation’s ability to recover from a catastrophic loss of military or commercial satellites, upon which the Nation today is critically dependent.

Phantom Express is envisioned as a highly autonomous experimental spaceplane, shown preparing to launch its expendable second stage on the top of the vehicle in this artist’s concept. The Defense Advanced Research Projects Agency is collaborating with Boeing to fund development of the Experimental Spaceplane (XS-1) program (Boeing rendering)
Phantom Express is envisioned as a highly autonomous experimental spaceplane, shown preparing to launch its expendable second stage on the top of the vehicle in this artist’s concept. The Defense Advanced Research Projects Agency is collaborating with Boeing to fund development of the Experimental Spaceplane (XS-1) program (Boeing rendering)

«The XS-1 would be neither a traditional airplane nor a conventional launch vehicle but rather a combination of the two, with the goal of lowering launch costs by a factor of ten and replacing today’s frustratingly long wait time with launch on demand», said Jess Sponable, DARPA program manager. «We’re very pleased with Boeing’s progress on the XS-1 through Phase 1 of the program and look forward to continuing our close collaboration in this newly funded progression to Phases 2 and 3 – fabrication and flight».

The XS-1 program envisions a fully reusable unmanned 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 3,000-pound/1,360-kg satellite to polar orbit. The reusable first stage would then bank and return to Earth, landing horizontally like an aircraft, and be prepared for the next flight, potentially within hours.

In its pursuit of aircraft-like operability, reliability, and cost-efficiency, DARPA and Boeing are planning to conduct a flight test demonstration of XS-1 technology, flying 10 times in 10 days, with an additional final flight carrying the upper-stage payload delivery system. If successful, the program could help enable a commercial service in the future that could operate with recurring costs of as little as $5 million or less per launch, including the cost of an expendable upper stage, assuming a recurring flight rate of at least ten flights per year – a small fraction of the cost of launch systems the U.S. military currently uses for similarly sized payloads. (Note that goal is for actual cost, not commercial price, which would be determined in part by market forces.)

To achieve these goals, XS-1 designers plan to take advantage of technologies and support systems that have enhanced the reliability and fast turnaround of military aircraft. For example, easily accessible subsystem components configured as line replaceable units would be used wherever practical to enable quick maintenance and repairs.

The XS-1 Phase 2/3 design also intends to increase efficiencies by integrating numerous state-of-the-art technologies, including some previously developed by DARPA, NASA, and the U.S. Air Force. For example, the XS-1 technology demonstrator’s propulsion system is an Aerojet Rocketdyne AR-22 engine, a version of the legacy Space Shuttle main engine (SSME).

Once Phantom Express reaches the edge of space, it would deploy the second stage and return to Earth. It would then land on a runway to be prepared for its next flight by applying operation and maintenance principles similar to modern aircraft (Boeing rendering)
Once Phantom Express reaches the edge of space, it would deploy the second stage and return to Earth. It would then land on a runway to be prepared for its next flight by applying operation and maintenance principles similar to modern aircraft (Boeing rendering)

Other technologies in the XS-1 design include:

  • Advanced, lightweight composite cryogenic propellant tanks to hold liquid oxygen and liquid hydrogen propellants;
  • Hybrid composite-metallic wings and control surfaces able to withstand the physical stresses of suborbital hypersonic flight and temperatures of more than 2,000º F/1,093º C;
  • Automated flight-termination and other technologies for autonomous flight and operations, including some developed by DARPA’s Airborne Launch Assist Space Access (ALASA) program.

XS-1 Phase 2 includes design, construction, and testing of the technology demonstration vehicle through 2019. It calls for initially firing the vehicle’s engine on the ground 10 times in 10 days to demonstrate propulsion readiness for flight tests.

Phase 3 objectives include 12 to 15 flight tests, currently scheduled for 2020. After multiple shakedown flights to reduce risk, the XS-1 would aim to fly 10 times over 10 consecutive days, at first without payloads and at speeds as fast as Mach 5/3,836 mph/6,174 km/h. Subsequent flights are planned to fly as fast as Mach 10, and deliver a demonstration payload between 900 pounds/408 kg and 3,000 pounds/1,360 kg into low Earth orbit.

Another goal of the program is to encourage the broader commercial launch sector to adopt useful XS-1 approaches, processes, and technologies that facilitate launch on demand and rapid turnaround – important military and commercial needs for the 21st century. Toward that goal, DARPA intends to release selected data from its Phase 2/3 tests and will provide to all interested commercial entities the relevant specs for potential payloads.

«We’re delighted to see this truly futuristic capability coming closer to reality», said Brad Tousley, director of DARPA’s Tactical Technology Office (TTO), which oversees XS-1. «Demonstration of aircraft-like, on-demand, and routine access to space is important for meeting critical Defense Department needs and could help open the door to a range of next-generation commercial opportunities».

Experimental Spaceplane (XS-1) Phase 2/3 Concept Video

Experimental Spaceplane

In an era of declining budgets and adversaries’ evolving capabilities, quick, affordable and routine access to space is increasingly critical for both national and economic security. Current satellite launch systems, however, require scheduling years in advance for an extremely limited inventory of available slots. Moreover, launches often cost hundreds of millions of dollars each, due in large part to the massive amounts of dedicated infrastructure and large number of personnel required. DARPA created its Experimental Spaceplane (XS-1) 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.

XS-1 Program to Ease Access to Space Enters Phase 2
XS-1 Program to Ease Access to Space Enters Phase 2

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 ten times in ten 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. A Special Notice was posted on April 7 on FedBizOpps announcing the XS-1 Phase 2 Proposers Day, to be held on Friday, April, 29, 2016, in Arlington, Virginia.

«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».

XS-1 envisions that a fully reusable unmanned booster vehicle would fly to 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 (LEO). The reusable first stage would then return to earth, land and be prepared for the next flight. Although relatively small by conventional aircraft standards, the XS-1 flight booster size – akin to a business jet – would be sufficient to validate credible scaling to larger reusable launch systems. Moreover, demonstration of on-demand and routine access to space, akin to aircraft, is important for next-generation DoD needs.

The same XS-1 vehicle could eventually also launch future 3,000+-pound/1,361-kilogram payloads by using a larger expendable upper stage
The same XS-1 vehicle could eventually also launch future 3,000+-pound/1,361-kilogram payloads by using a larger expendable upper stage

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/408- to 680-kilogram 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/1,361-kilogram payloads by using a larger expendable upper stage.
  • Reduce the cost of access to space for 3,000+-pound/1,361-kilogram 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).

Successful design would require integrating state-of-the-art technologies, processes and system approaches to deliver routine aircraft-like operability, reliability and cost efficiency. In particular, incorporation of autonomous technology and operations promises to significantly decrease the logistical footprint and enable rapid turnaround between flights. Structures made of advanced materials, cryogenic tanks, durable thermal protection, and modular subsystems would make possible a vehicle able to launch, fly to high speeds and then land in a condition amenable to rapid turnaround and launch with the next payload. Reusable, reliable propulsion would also be essential for a low-cost and recurring flight capability.

In Phase 1 of XS-1, DARPA sought to evaluate the technical feasibility and methods for achieving the program’s goals
In Phase 1 of XS-1, DARPA sought to evaluate the technical feasibility and methods for achieving the program’s goals

In Phase 1 of XS-1, DARPA sought to evaluate the technical feasibility and methods for achieving the program’s goals. To achieve that, it awarded prime contracts to three companies, each working in concert with a commercial launch provider: The Boeing Company (working with Blue Origin, LLC); Masten Space Systems (working with XCOR Aerospace); and Northrop Grumman Corporation (working with Virgin Galactic). Phases 2 and 3 will be competed as a full and open Program Solicitation mandating an Other Transaction Authority (OTA) agreement with the expectation of a single resulting award. Cost share is expected.

Specifically, the program is structured to directly transition any successful technology to the industrial and commercial launch sectors, with the goal of enabling new launch markets and sale of launch services back to the government at dramatically lower costs and more rapid time frames than are possible today. By ensuring the technologies and launch systems would be available through the commercial sector, government leaders would have the opportunity to begin relying on XS-1 and derived systems. Militarily-relevant applications of the technology may also spur adoption and help enable future capabilities such as disaggregated spacecraft architectures and next-generation, reusable space-access aircraft.