J-2X engine test

Technicians lower a complete J-2X engine into position for a test-firing at NASA's Stennis Space Center in 2013. NASA announced in October that it will idle the J-2X development program after testing finishes in 2014. (NASA photo)

HUNTSVILLE, Alabama - NASA has spent $1.2 billion to design, build and test a powerful new upper-stage rocket engine for the future called the J-2X. But after final testing next year, the new engine will wait to see if there's a mission for it. And the decision to park the J-2X has the space agency trying its first week back from shutdown to get out in front of criticism that it wasted money by the boxcar-load on an engine it may never use.

The J-2X wasn't a waste to develop, a NASA spokeswoman said in Huntsville Monday, and it was never intended for the new rocket launcher NASA is developing now at Marshall Space Flight Center. When America decides to go to Mars or somewhere else beyond the moon, NASA said, it will need a larger rocket, and the J-2X could still be the upper-stage engine that powers it.

But for the two missions actually on the books for the Space Launch System (SLS), as the new launch system is called, NASA says it can do the job of lifting the upper stage into space cheaper with other engines. That will increase the odds it actually will get the first phase flying on budget and thus a chance to build the larger second version.

Aviation Week reporter Frank Morring Jr. first reported Oct. 4 during the government shutdown that NASA would put the J-2X "on the shelf" after development testing ends next year at Stennis Space Center in south Mississippi. Morring's story was headlined, "NASA's J-2X engine to be mothballed after testing."

Writing on the policy website PolicyMic Monday, writer Christopher Blakely called the J-2X an example of aspirations without realistic plans. In other words, NASA was dreaming when it went ahead with the J-2X, which had originally been part of a rocket system called Constellation that President Obama canceled in 2009. Blakely's piece had a headline calling the J-2X "NASA's $1.2 billion mistake."

Kim Henry, a spokeswoman for the Space Launch System being developed at Marshall Space Flight Center in Huntsville, said Monday that the J-2X was never planned for the 70-metric-ton launch system NASA is building now. That's the size payload the first SLS must lift in the two test missions now planned for 2017 and 2021.

"The J-2X engine is among the engine options anticipated to power the upper stage of the evolved 130-metric ton Space Launch System," NASA said in a statement. "As future missions are defined for the 130-metric ton SLS, the largest configuration planned, NASA will consider various engine options that are the best value and design."

NASA always planned to extend J-2X only through testing, NASA said. Having the engine in the test stand, the statement said, has been "critical to maintaining SLS and aerospace workforce skill levels and the liquid propulsion industry base."

There have been hardware benefits, too, the statement said, calling the engine "a test bed for manufacturing improvements like 3-D printing of complex rocket engine components and new materials like the liner for the main combustion chamber." Those lessons will help as NASA modifies the leftover space shuttle main engines it plans to use to help lift the SLS core stage.

"J-2X design, manufacturing and test improvements are being implemented for a more affordable ... core stage engine," the statement said.