June 2, 2023 - Aerojet Rocketdyne will deliver and demonstrate a large, single-piece, additively manufactured rocket engine thrust chamber and a quick disconnect, low leakage coupling mechanism for in-space cryogenic fueling under a pair of NASA Space Act Agreements intended to support the agency’s space exploration goals.
NASA’s Space Technology Mission Directorate (STMD) selected two Aerojet Rocketdyne proposals under its 2022 Announcement of Collaboration Opportunity (ACO), an initiative intended to help industry advance technologies relevant to government and commercial use of space: the fully Additively Manufactured LOX-LH2 Demonstration Engine (AMDE); and the Electrically Actuated Quick-Disconnect (ELECTRA-QD) coupling for cislunar and lunar surface cryogenic propellant transfer.
NASA will provide in-kind resources, including engineering expertise and facilities, under the unfunded agreements, which will culminate in operationally realistic demonstrations within the next two years. Aerojet Rocketdyne will fund AMDE component and ELECTRA-QD developments internally, collaborating with NASA’s Marshall Space Flight Center in Huntsville, Alabama, on both efforts.
“ELECTRA-QD is a quick disconnect, low leakage coupling device with an electrical actuator for vehicle fueling, either in cislunar space or on the lunar surface,” said Leslie Woodger, Aerojet Rocketdyne’s program manager. “The complex device contains dozens of components, many of which will be additively manufactured using a variety of alloys.”
“Aerojet Rocketdyne has already produced designs and mockups of the device at our facility in Canoga Park, California,” added Woodger. “However, this will be first time we’re fabricating ELECTRA-QD for testing.”
Once fabricated, the device will be shipped to Marshall for a demonstration that will involve mating the two ends within a representative docking system provided by NASA, flowing cryogenic fluids through the connection, de-mating and then checking for leaks. The 21-month effort is expected to take the coupling mechanism from Technology Readiness Level (TRL) 3, essentially a design, to TRL 5, a tested prototype.
“We’re working with the engineering team at Marshall to establish requirements to create test plans and perform the test,” Woodger said, adding that Peter Kinsman is Aerojet Rocketdyne’s principal investigator and lead engineer on the effort.
The device is designed to withstand axial loads—pressures exerted on the coupling by relative movement of the larger docked structure—better than “bayonet-style” coupling mechanisms, Woodger said.
“In an exploration scenario, ELECTRA-QD as currently scaled could support fueling of lunar landers—carrying cargo or humans—at the Gateway logistics platform in cislunar space for descent to the surface, or ascent vehicles headed back to the Gateway,” Woodger said. “The device could be scaled up or down to fuel smaller or larger space vehicles.”
“Under the 22-month AMDE effort, meanwhile, Aerojet Rocketdyne will additively manufacture a single-piece thrust chamber assembly, including the injector, for a 35,000-pound thrust engine built by NASA,” said Bryan Webb, the company’s program manager. “The engine currently has a conventionally produced thrust chamber assembly and Aerojet Rocketdyne’s additively manufactured hardware will serve as a drop-in replacement.”
Additive manufacturing enables the use of simplified geometries for engine component production and cuts down on the number of welds, which are labor intensive and require certification. The result will be higher reliability and lower costs.
“We have a basis for making these components and the novel aspect is integrating the injector into a single-piece thrust chamber design,” Webb added. This effort will help pave the way to producing larger additively manufactured components.
The thrust chamber assembly to be manufactured and tested under this agreement will be sized for the NASA AMDE, which would be appropriate as the second stage of a large rocket or an in-space propulsion system, but the technology could be scaled to serve as a first-stage engine.
