COBRA, short for Co-optimized Booster for Reusable Applications, is a reusable, hydrogen-fueled liquid booster and second stage engine with a thrust level of 600,000 pounds of force. The engine is being developed by Pratt & Whitney-Aerojet Propulsion Associates - a joint venture of Aerojet of Sacramento, Calif., and Pratt & Whitney Space Propulsion of West Palm Beach, Fla.
The preliminary design review is a lengthy technical analysis that evaluates the engine design to ensure achievement of system requirements and Space Launch Initiative (SLI) goals of improved safety, reliability, cost and operability. The review is conducted when the engine design is approximately 50 percent complete and engine drawings are approximately 10 percent complete.
"The review is the first of several major system engineering control gates to evaluate where we are, and to make sure we are on the right path to produce a rocket engine prototype that will be simple to operate and inherently reliable and thus low cost," said Jim Snoddy, project manager for COBRA at NASA's Marshall Space Flight Center in Huntsville, Ala.
COBRA is a single fuel-rich preburner, staged combustion engine using liquid oxygen and liquid hydrogen as propellants. The engine aims to provide a 100-mission life span with a 50-mission maintenance check-up interval. Using an inherently reliable engine cycle and numerous state-of-the-art technologies derived from the Space Shuttle Main Engine, the COBRA engine fuses the knowledge and experience of the first generation Space Shuttle Program with advancing second generation research and technology development.
"COBRA utilizes several Space Shuttle Main Engine technologies, including the advanced turbopump design for both of the high-pressure turbopumps and key sensors for advanced health management," said Snoddy. "In addition, COBRA has taken on development of the channel wall nozzle to help meet second generation goals. Combining the lessons learned from the Shuttle program with advancing technologies will enable us to develop an advanced engine candidate for the second generation reusable launch vehicle."
The COBRA engine is one of two hydrogen-fueled engine designs being evaluated as a first or second stage option for the next generation reusable launch vehicle. Kerosene-fueled engines are also being considered for the first stage booster. Engineers at the Marshall Center will narrow engine options based on SLI requirements.
The Space Launch Initiative is the beginning of a new era of human space flight for NASA by furthering technologies needed to develop the next generation launch vehicle. The Marshall Center manages the Space Launch Initiative for NASA's Office of Aerospace Technology.