Approved for Public Release - 08-MDA-3570 (25 JUNE 08)
A joint industry-academic team led by California State University, Long Beach (CSULB) with technical support from Garvey Spacecraft Corporation (GSC) and funding from the Missile Defense Agency conducted the first integrated static fire test of its advanced multi-chamber aerospike engine integrated into the newly developed Prospector-10 (P-10) prototype vehicle. The test, conducted on May 17, 2008, demonstrated successful ignition of all ten chambers and operation of the propellant tank regulated helium pressurization system, as well as of the onboard data acquisition and telemetry systems, although the burn was terminated one second short of the planned 4 second duration due to a gasket failure at one of the chamber/injector interfaces.
Aerospike engines have yet to be used on any operational system despite the promise of improved performance, owing in large part to the fact that no flight data is available to characterize the interactions between airframe and engine, most notably in transonic, under-expanded flight conditions. The multi-chamber 1,300 lbf thrust LOX/ethanol aerospike engine is designed to address this need. It is comprised of ten (10) thrusters which incorporate ceramic matrix composite (CMC) thrust chambers in order to maintain the square 0.6 inch throat and rectangular nozzle constant during the burn. The CMC components were manufactured by Hypertherm High Temperature Composites of Huntington Beach, CA. The thrusters are arranged around an annular plug nozzle to further increase the area ratio. The plug is outfitted with a series of pressure sensors in order to obtain flight performance data to be later used for computational fluid dynamics (CFD) tool validation. The engine is integrated into a regulated-helium pressure-fed vehicle which features flight data acquisition and telemetry systems. Vehicle structures are mostly made of carbon-epoxy composites, with expertise in design and manufacture provided Frederick Courouble, partner in Kernan Yacht Design, Long Beach, CA. Sensors include an inertial measurement unit for trajectory determination, propulsion system pressure transducers, as well as multiple skin pressure sensors. The vehicle is designed to reach supersonic conditions at approximately 15,000 ft and burnout shortly thereafter, coasting to 25,000 ft before a 2-stage parachute recovery.
Due to the injector/CMC thruster leak and a subsequent fire internal to the vehicle, however, some of the avionics components experienced various degrees of damage. Nevertheless, sufficient data was recovered from the on-board telemetry system to show that the engine generated above 800 lbf of thrust at the about 200 psia reduced chamber pressure (compared to 300 psia for nominal conditions). A complete analysis of the data as well as the root cause of the gasket failure is ongoing. Damage assessment is also being conducted in order to determine if the team will be able to conduct an instrumented flight test as initially planned. The flight data would later be analyzed to determine airframe-engine interactions and the associated engine performance, and would be used for comparisons with CFD approaches.
1,300 lbf thrust aerospike engine during the 3 s burn
Prospector 10 vehicle being raised into Friends of Amateur Rocketry large vertical test stand
P-10 integrated into test stand with thermocouples used for automatic aerospike engine ignition detection
Right at engine ignition
Engine in operation with a transparent plume typical of LOX/ethanol engines
Close-up of engine after static fire test
For additional information about either the CALVEIN project and/or the cooperative program between CSULB and Garvey Spacecraft Corporation, please contact the following project representatives: