A paper discusses a prototype rocket engine for a suborbital Reusable Nanosat Launch Vehicle (RNLV). The engine must operate with thrust levels from 3,000 to 5,000 lbf. The engine is comprised of three major subassemblies: the injector, igniter, and the combustion chamber nozzle. Propellants are introduced and mixed in the combustion chamber utilizing a combination of triplet and unlike doublet injector elements. In addition, film cooling is provided in order to extend the life of the ablative chamber. Ignition is accomplished with solid propellant ports mounted on the side of the chamber.
Ten static fire tests have been completed to validate the design and to characterize the engine's performance. Initial testing was conducted to validate the ignition algorithm and verify the engine's basic integrity at startup. Further testing was conducted to verify engine performance before flight testing. Data shows that the engine can operate at thrust levels between 2,500 and 5,074 lbf. This successful engine development serves as a precursor to a future NLV first-stage engine that will utilize LOX-propylene for added performance.
This work was done by George Haberstroh and Eric Besnard of California State University, Long Beach; and Matthew Baker and John Garvey of Garvey Spacecraft Corp. for the Air Force Research Laboratory.