CLEAN STEAM ROCKET ENGINE PASSING TESTS.

Byline: Charles F. Bostwick Staff Writer

EDWARDS AIR FORCE BASE - Boeing Rocketdyne is wrapping up Edwards Air Force Base tests of an engine, fueled with liquid hydrogen, designed for the new Delta IV rocket.

Strapped into the steel-and-concrete test stand that once held Apollo F-1 engines, the RS-68 engine has been fired for as long as 160 seconds as the company determines if it is ready for space flight.

``It's been highly successful for us,'' Boeing Rocketdyne spokesman Dan Beck said last week.

The Delta IV is being created for the Air Force's evolved expendable launch vehicle or EELV program. This is one of the efforts by the National Aeronautics and Space Administration and the Air Force to reduce the cost of launching satellites and other space cargo. The Delta IV incorporates features from the earlier Delta versions with new technologies and processes to reduce costs, Beck said.

At some point Boeing would like to market the Delta IV for commercial satellite launches, Beck said.

The first Delta IV launching is tentatively scheduled for 2002. Boeing has been awarded contracts for 19 of the EELV launches. Competitor Lockheed Martin will handle nine.

Testing at Edwards is expected to conclude in May. Then the focus will shift to NASA's Stennis Space Center in Mississippi, where there are test stands with larger fuel and liquid oxygen tanks that will accommodate longer firings - up to 265 seconds.

The engine has undergone 117 test firings at Edwards and Stennis so far.

Boeing officials say the hydrogen-fueled RS-68 is 30 percent more efficient than a rocket engine running on liquid oxygen and kerosene, such as the F-1 engines that powered the Apollo rockets.

A hydrogen engine is also environmentally more benign, producing steam as its exhaust byproduct, officials say.

``It's much cleaner,'' said Ranney Adams, spokesman for the Air Force Research Laboratory Propulsion Directorate, whose test stands at Edwards are being used for Boeing's tests.

With 650,000 pounds of thrust at sea level, the RS-68 is the most powerful liquid-hydrogen fuel engine. The space shuttle main engine, another liquid-hydrogen design, produces 418,660 pounds of thrust.

In comparison, the F-1 - America's most powerful engine - produced 1.5 million pounds of thrust.

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2 photos

Photo:

(1) Boeing is wrapping up tests at Edwards Air Force Base of an engine fueled by liquid hydrogen for the new Delta IV rocket. The first Delta IV launching is tentatively scheduled for 2002.

(2) A Boeing RS-68 rocket engine, fueled with liquid hydrogen, releases steam as exhaust - much cleaner than other rocket engines, says Air Force researcher Ranney Adams.