Status: Developed 2005-. Date: 2005-. Thrust: 133 N (29 lbf).
In November 2005, Orbital Technologies Corporation (ORBITEC) of Madison, Wisconsin, completed successful testing of a prototype rocket engine using methane fuel and oxygen oxidizer. Methane was of interest for NASA's Vision for Space Exploration and for future USAF launch vehicles. It required smaller propellant tanks than hydrogen, had higher specific impulse than hydrocarbon fuels such as kerosene, and when used for exploration, methane and oxygen could be produced on Mars from planetary resources found there. NASA was interested in applying liquid methane/liquid oxygen propellants for Lunar and Mars landing and other transport vehicles. The USAF was interested in methane for future use in launch vehicles. ORBITEC believed this technology would enable the development of low-cost, reusable rocket engines for spaceplanes, suborbital and orbital launch vehicles, and orbital transfer stages for a variety of military and civil space missions.
The ORBITEC engine used ORBITEC's patented "vortex-cooled" combustion process to eliminate combustion chamber heating. ORBITEC conducted over 70 hot firings with the vortex-cooled methane engine to refine the design of the propellant injectors and combustion chamber. This program resulted in a design that provided very high performance - 98 percent of an ideal rocket with no significant chamber heating upstream of the exit nozzle. The chamber operated at a thrust of approximately 133 newtons and a chamber pressure of 1.03 megapascals. Similar testing with hydrogen in a larger chamber also demonstrated very low chamber heating at pressures of 3.45 megapascals and high performance.
ORBITEC has also conducted successful methane/oxygen ignition system developments and has applied them to its larger rocket engine testing. ORBITEC previously conducted successful engine firing tests of solid methane and solid methane-aluminum in cryogenic solid hybrid rocket engines with gaseous oxygen. This current research was being conducted with the support of a Phase 3 SBIR contract from the AFRL.