NASA Eyes Alternative to Shuttle Main Engine

NASA is considering dropping the Space Shuttle Main Engine (SSME) from its heavy-lift launch vehicle plans and using the cheaper-to-manufacture RS-68 engine instead.

Daniel Dumbacher, deputy director of the Exploration Launch Office at NASA's Marshall Space Flight Center, Huntsville, Ala., told reporters following his presentation at the Goddard Memorial Symposium here March 14 that a formal trade study is under way to examine the cost, schedule and performance merits of the SSME and RS-68. At present those two engines are NASA's first choice for the main stage engines that would power the planned heavy-lift cargo launcher NASA intends to build to boost payloads on their way to the Moon.

Dumbacher said the trade study would be completed this spring. "It's got to be done in the next month or so because it plays a factor in how we do our budget planning," he said.

If NASA goes with the RS-68, then the SSME would have no obvious future beyond the space shuttle program, which is slated to end in 2010.

From here

Interesting. Looks like NASA has some tugging in different directions still going on. If only there was some way to get the Congress critters to give them enough money to do both VSE and all that wonderful science.