STENNIS SPACE CENTER, Miss. (Aug. 27) - A Space Shuttle Main Engine "recovered" after splash-down in inland waters here was successfully test-fired today by a Boeing-Rockwell-NASA test team.

The six-minute test firing completed a dramatic, highly successful design demonstration program that has shown that the Boeing approach of recovering and reusing costly rocket engine systems can save U.S. taxpayers billions of dollars in launch costs.

The summer-long test program has been carried out by Boeing for the U.S. Air Force Evolved Expendable Launch Vehicle (EELV) program, an Air Force-led effort to bring down the costs of launching U.S. payloads into space.

The NASA space shuttle engine involved in today's test had been installed in a prototype propulsion module, and dropped twice from a crane into the waterways here at the NASA John C. Stennis Space Center.

The engine was then inspected and installed in a test stand, and fired for 360 seconds - producing some 375,000 pounds of thrust. The test cycle replicates what would be experienced during actual operation of the proposed Boeing EELV system, which returns costly engine components to earth in a water-tight module so they can be used over and over again. (Current expendable launch vehicles allow engines to fall to the bottom of the sea after just a single use.)

"With today's successful engine firing, the Boeing team has met all the objectives of our test program," said Boeing EELV program manager Tim White in Seattle. "We've proven that the age of reusability in expendable launch vehicles - and with it tremendous cost savings - is indeed within our grasp."

Space Shuttle Main Engine (SSME) 2107 was throttled between 65 percent and 100 percent of its rated capacity, with more than 1,000 pounds of rocket fuel per second flowing through the engine at peak thrust. Engineers collected data from hundreds of instruments measuring performance during the test, and a preliminary analysis showed all engine systems functioned normally.

The SSME is the only reusable main engine produced in the U.S., and Boeing is the only EELV contractor to incorporate the SSME and the economies of reusability in its design. Shunning the current practice of throwing away costly main engines with every launch, the Boeing EELV would recover and reuse main engines 25 or more times per engine. Today's test was the 51st successful firing of engine 2107.

"Today's test brings to a very successful conclusion an outstanding demonstration program," said NASA EELV program manager Steve Nunez. "We have shown that partial reusability works, and we have proven the durability of the space shuttle main engine to fulfill the EELV main engine role."

NASA and shuttle engine manufacturer Rocketdyne are subcontractors to Boeing on the EELV program. Today's test was managed by Nunez and Boyce Mix of NASA, John Plowden and Dave Geiger of Rocketdyne, and Don Graves of Boeing.

Boeing is one of four companies under contract to the Air Force to develop a cost-saving space launch system for Department of Defense and other U.S. government payloads.