XCOR Reaches Milestone in Liquid Hydrogen Engine Program

The XCOR XR-5H25 engine was hot fired for the first time at the XCOR test site located on the Mojave Air & Space Port in Mojave, California. (Credit: XCOR)
The XCOR XR-5H25 engine was hot fired for the first time at the XCOR test site located on the Mojave Air & Space Port in Mojave, California. (Credit: XCOR)

Nov. 19, 2013, Mojave, CA and Centennial, CO. (XCOR/ULA PR) — XCOR Aerospace and United Launch Alliance (ULA) announced a significant milestone today, the first successful hot fire of the subscale 2500 lbf thrust XR-5H25 engine in the XCOR® and ULA liquid hydrogen (LH2) engine development program.

“The first hot fire of any engine is a major milestone but the first firing of a liquid hydrogen engine in our LH2 program is an even bigger accomplishment,” noted XCOR Chief Executive Officer Jeff Greason. “The hot fire of this engine moves us forward on a path to routine tests and further demonstration of fully reusable, high reliability rocket engines for which we are known.”

“XCOR’s ability to develop inexpensive, innovative and out-of-the-box solutions to some of the most challenging problems in modern cryogenic rocket engine technology was on display in Mojave,” said George Sowers, vice president of Strategic Architecture at ULA. “It was a great first set of engine runs and we look forward to seeing the engine and XCOR’s unique piston pumps integrated together in 2014.”

Conceived as a lower-cost, risk-managed approach, the goal of the XCOR/ULA LH2 engine program is to produce and operate a subscale demonstration engine. This demonstrator will enable a future decision to pursue development of a flight-ready cryogenic upper-stage engine in the 25,000 lbf thrust class. The technology has significant growth potential due to its unique thermodynamic cycle and piston pump. The larger thrust XCOR XR-8H21 LH2 engine should cost significantly less to produce and be much easier to operate than competing upper stage rocket engine technologies.

XCOR Chief Operating Officer Andrew Nelson said “I was very impressed with how our team dedicated itself to achieving a task that has not been accomplished in at least a quarter century, maybe more; the development of a new way to do liquid hydrogen rocket engines that fundamentally breaks current cost, reliability and operational models. Even more than that, it will be the first piston-pump-fed LH2 rocket engine anywhere.”

The 5H25 engine is intended as a testbed, but could also be suitable for future in-space use on upper stages, earth departure stages, landers, and probes. Nelson added, “This is a significant leap forward in the hope to deliver yet another line of innovation and business to XCOR. And it is only taking place right here.”

About XCOR Aerospace: XCOR Aerospace is based in Mojave, California. It is currently starting the process to create a new Research and Development Center in Midland, Texas and an operational and manufacturing site at the Kennedy Space Center in Florida. XCOR® builds safe, reliable and reusable rocket-powered vehicles, propulsion systems, advanced non-flammable composites and rocket piston pumps. XCOR works with aerospace prime contractors and government customers on major propulsion systems, while also building Lynx®. Lynx is a piloted, two-seat, fully reusable liquid rocket-powered vehicle that takes-off and lands horizontally. The Lynx-family of vehicles serves three primary missions depending on their specific type including: research & scientific missions, private spaceflight, and micro satellite launch (only on the Lynx Mark III). Lynx production models (designated Lynx Mark II) are designed to be robust, multi-mission (research / scientific or private spaceflight) commercial vehicles capable of flying to 100+ km in altitude up to four times per day. Lynx vehicles are available to customers in the free world on a wet lease basis to start their own manned space flight program. (www.xcor.com).

United Launch Alliance: ULA is a 50-50 joint venture owned by Lockheed Martin and The Boeing Company, and is the nation’s rocket company, bringing together two of the launch industry’s most experienced and successful teams – Atlas and Delta. ULA provides reliable, cost-efficient space launch services for the Department of Defense, NASA, the National Reconnaissance Office and other commercial organizations. ULA program management, engineering, test, and mission support functions are headquartered in Denver, Colo. Manufacturing, assembly and integration operations are located at Decatur, Ala., and Harlingen, Texas. Launch operations are located at Cape Canaveral AFS, Fla., and Vandenberg AFB, Calif. For more information on ULA, visit the ULA Web site at www.ulalaunch.com, or call the ULA Launch Hotline at 1-877-ULA-4321 (852-4321). Join the conversation at www.facebook.com/ulalaunch and twitter.com/ulalaunch.

  • Andy

    Why is the plume so orange? Ablative carbon liner like the RS-68?

  • delphinus100

    I’m thinking it’s running hydrogen-rich…

  • Stuart

    Interesting colour of rocket flame, has it been photo shopped? Is the fuel mixture a secret?

  • dr

    AFAIK Hydrogen usually burns with an Ultraviolet coloured flame. I’m wondering if it is running on something like Methane at the moment.

  • dr

    Also, correct me if I’m wrong, but is it not usually the case, that the higher the exhaust velocity, the clearer the shock diamonds? If this is true, then this engine isn’t running at the kind of exhaust velocity you would expect for an LH2 / LOX engine. I guess that means that either its running a third fuel component for some reason, or its a long way from stoichiometric.

  • Andy

    I thought LOX/LH2 pretty much burned light blue to clear regardless of mixture ratio. Although the SSME’s had that orange poof of flame at startup so I could be wrong.

  • Hug Doug

    No, and No. It even says in the very first sentence of the article – it’s a Liquid Hydrogen fueled rocket.

  • Hug Doug

    PURE hydrogen and oxygen burns with a pale blue flame, yes. if there are contaminants, even in very, very minute amounts, it will shift in color. industrial hydrogen produced in the US (such as used in the Shuttle launches) is typically contaminated with sodium (on the order of hundredths of parts per billion), which when burned produces an orange flame.

  • Hug Doug

    PURE hydrogen and oxygen burns with a pale blue flame, yes. if there are contaminants, even in very, very minute amounts, it will shift in color. industrial hydrogen produced in the US (such as used in the Shuttle launches) is typically contaminated with sodium (on the order of hundredths of parts per billion), which when burned produces an orange flame.

  • dr

    So that’s why I thought it looked like the colour of a streetlight…

  • Andy

    The shuttle exhaust looked orange for a brief moment at start up. At steady state is was light, light blue if it was visible at all. It didn’t look like the exhaust in this picture.

  • Hug Doug

    doing some more research – it seems the orange flame on SSME startup is from contaminants in the surrounding air. hydrogen pools near the base of the shuttle before launch, from pressure vents higher up. it’s this hydrogen that ignites and burns orange.

  • Andy

    Ah. Okay. So I guess XCOR’s LH2 delivery had some contaminants in it?

    Another thought I had is they seeded the plume with sodium for flow visualization purposes since the invisible exhaust of pure LH2/LOX makes it difficult to shakedown bugs – after all, it was the very first run for this engine.

  • Hug Doug

    I would presume that “pure” hydrogen would be more expensive than “industrial grade” hydrogen… but that’s just a guess.