Aerojet Rocketdyne Successfully Tests Re-generatively Cooled, 3D Printed RL-10 Thrust Chamber

A re-generatively cooled, 3-D printed thrust chamber assembly for the next generation of RL10 rocket engines undergoes hot-fire testing at Aerojet Rocketdyne’s facility in West Palm Beach, Florida. (Credit: Aerojet Rocketdyne)

WEST PALM BEACH, Fla., June 13, 2018 (Aerojet Rocketdyne PR) — Aerojet Rocketdyne recently achieved a significant milestone by successfully completing a series of hot-fire tests of an advanced, next-generation RL10 engine thrust chamber design that was built almost entirely using additive manufacturing; commonly known as 3-D printing.

“This recent series of hot-fire tests conducted under our RL10C-X development program demonstrated the large-scale additive manufacturing capability we are maturing to help reduce the cost of this legendary engine system while continuing to provide reliable performance,” said Aerojet Rocketdyne CEO and President Eileen Drake. “This marks another important milestone in our effort to fully qualify components built with additive manufacturing for use in many of our production engine systems.”

The company first demonstrated that a 3-D printed copper alloy thrust chamber and nickel alloy main injector were possible just over a year ago when it completed successful testing of a 3-D printed thrust chamber assembly. The recent round of tests, which took place at the company’s facility in West Palm Beach, Florida, built on the prior work by incorporating a new 3-D printed copper alloy thrust chamber assembly design to accommodate a new re-generatively cooled nozzle that was 3-D printed from a nickel-based alloy.

Current production versions of the RL10 use a complex array of drawn, stainless steel tubes that are brazed together to form a thrust chamber. Incorporating 3-D printing into the process will reduce overall lead time by several months, which in turn will reduce production costs.

“Hot-fire testing helps us validate the approaches we are using to fabricate and join parts that are produced through additive manufacturing to ensure they meet our requirements for materials characterization, structural integrity and durability,” said RL10 Senior Program Director Christine Cooley. “We are also able to accurately define the amount of heat-transfer that is taking place so we can optimize the performance of our next generation of RL10 engines.”

“We continue to look for ways to insert additive manufacturing into our liquid rocket engine designs to not only reduce their cost, but to open up creative design spaces that the additive manufacturing process enables,” added Drake. “This latest round of testing demonstrates that we can systematically print and assemble an engine that can replicate the proven RL10 performance in a fraction of the time and at a reduced cost. Additive manufacturing technology also enables new approaches to engine design that we are now exploring through sub-system testing and validation.”

Aerojet Rocketdyne, a subsidiary of Aerojet Rocketdyne Holdings, Inc. (NYSE:AJRD), is an innovative company delivering solutions that create value for its customers in the aerospace and defense markets. The company is a world-recognized aerospace and defense leader that provides propulsion and energetics to the space, missile defense and strategic systems, tactical systems and armaments areas, in support of domestic and international markets. Additional information about Aerojet Rocketdyne can be obtained by visiting our websites at and

  • P.K. Sink

    The good news…evolve or die. The bad news…am I paying for this work?

  • Do you pay taxes? Yeah, we’re paying for ALL of them.

    Whether it’s a direct a NASA/DoD test or one of their contractors (ULA, SpaceX, whatever), or it’s a development from an earlier era (do the tests take place at Stennis, Bluebonnet – now SpaceX in McGregor – or West Palm Beach), you or your past family members are ALWAYS paying for it.

    Spaceport America? taxpayer money
    Mojave Spaceport? taxpayer money
    SpaceX’s site at Jack Northrop Field (as in the old NORTHROP Grumman site)? taxpayer money

  • P.K. Sink

    Yeah…actually I’m rooting for AR to stay in the game. I’m just a little annoyed that they’re getting so much money for an engine…AR 1…that doesn’t appear to have a rocket.

  • Yeah, we can’t seem to figure out our tech funding schedules. The complaint from 10 years ago was that we didn’t have a perpetual program to develop engines – like Russia does. If had, then AR-1 would be on the shelf and Atlas V could have switched already.

    Is that the BEST way to build rockets? I don’t know.

    The American philosophy has been to get an engine/motor and then just keep upgrading until you just have to start all over again with a totally new system. Because of that, you can count the American engine/motor families on two hands (you might need a foot). We haven’t really developed THAT many engines. Meh, it seems to work for us.

    RL10 will go on forever…

  • envy

    The USAF has an $86M or more contract with ULA to support development of propulsion systems for the ACES upper stage. RL-10 was chosen for ACES, so most of that money probably went to this work.

    AJRD is undoubtedly putting some of their own money on the line, the only question is how much. Based on their behavior with AR-1, their share is probably pretty small compared to how much they are getting from ULA and the USAF.

  • envy

    Spaceport America and Mohave Air and Space Port are primarily funded by county and state taxpayers, and by private tenants who use the facilities.

    SpaceX owns a manufacturing facility adjacent to Northrop Field (Hawthorne Municipal Airport), but doesn’t use the airport for spacecraft flights. That facility is not directly or indirectly paid for by taxpayers.

  • Like I said, taxes. Municipal airports budgets from a combination of local and federal taxes. Those taxes you pay on your airline tickets and jet fuel? The airport improvement funds gotta come from somewhere.

    SpaceX’s building is the old Northrop building. It’s just like today, SpaceX, ULA, Blue and others put buildings where they get tax breaks. States fight over this stuff with taxpayer dollars. Either they get tax dollars to pay for the buildings outright or they get tax dollars to fund development or tax dollars for production that they use to secure a loan to build the building.

    I’m not saying it’s WRONG, it’s just the game. It you want to do well in the game, you have to play a certain way.

  • Gary Church

    Not many comments here. Have all the Musk fanatics gone somewhere else?

  • envy

    All dollars are tax dollars if you follow them far enough back. That’s a fairly pointless exercise. Anything that the government doesn’t have a contract to pay for isn’t being paid in tax dollars.

    In the case of RL-10 development, there is a specific contract for that service. The USAF is paying ULA directly to get a propulsion system developed for Vulcan’s upper stage.

    Also, tax breaks aren’t tax dollars, they are the lack of theoretical tax dollars, which might (or might not) have been real tax dollars in an alternate reality where they were paid. Quite often, they wouldn’t have been paid in any case.