Volume 5, Number 5     September/October 1997

Aerospace Technology Development

Next-Generation Rocket Engine Advances

CRITICAL SERIES OF TESTS ON A ROCKET engine that could power the next generation of space launch vehicles has been successfully completed at the Marshall Space Flight Center in Huntsville, Alabama. The Fastrac engine—only the second American-made engine developed in the last 25 years—will be the primary propulsion system for the X-34 technology demonstration vehicle scheduled to begin flight tests in late 1998.

The X-34 is next in NASA's series of Reusable Launch Vehicle (RLV) technology demonstrators set for up to 25 flights beginning late next year. The X-34, an air-launched vehicle, is intended to demonstrate technologies ranging from composite structures and reusable propellant tanks and insulation to advanced thermal protection systems and low-cost avionics.

X-34 demonstrations will precede the more advanced X-33 technology demonstrator scheduled to begin flights up to Mach 15 in mid-1999. A major goal of NASA's RLV efforts is to reduce dramatically the cost of putting payloads into space.

Marshall Space Flight Center engineers conduct a series of tests evaluating the main propulsion system for the 1998 X-34 demo flight tests, which have been successfully completed in near-identical flight conditions.

Recently completed Fastrac engine component tests evaluated the engine's thrust chamber assembly at high pressure almost identical to flight conditions. "The thrust chamber assembly performed as designed, which is another indication that the Fastrac is an engineering breakthrough," said George Young, Fastrac engine chief engineer. "Marshall engineers developed this engine in a much shorter-than-usual design cycle at significantly lower costs than a typical rocket engine."

The Fastrac engine uses simple open-looped control to minimize the expense of control valves and electronics. The engine thrust chamber is made of silica-phenolic ablative material overwrapped with graphite fiber. This part can be manufactured using commercial techniques at a much lower cost than typical tube-type thrust chambers. The engine injector has been simplified to include only three parts, a two-piece injector body and a brazed-on copper faceplate.

Each Fastrac engine initially will cost approximately $1 million—about one-fourth the cost of similar engines. The Fastrac provides 60,000 pounds of thrust and, in addition to the X-34 vehicle, is targeted for launch systems designed to boost payloads weighing up to 500 pounds at a dramatically lower cost.

The Fastrac engine is being called "an engineering breakthrough" after its thrust chamber assembly performed successfully. Designers developed the engine in record time at lower costs.

For more information, contact Daniel Davis at Marshall Space Flight Center.
Call 205/544-0034 E-mail: Daniel.J.Davis@msfc.nasa.gov

Please mention you read about it in Innovation.