Solid-rocket motor builder Alliant Techsystems (ATK) Aerospace of Magna, Utah, laid off 247 workers the week of May 17 as work winds down on NASAโ€™s space shuttle program and on a Minuteman ICBM-related contract.

ATK spokesman George Torres said the move, due mainly to the impending retirement of the space shuttle, was one of a series of planned layoffs that have reduced the Aerospace divisionโ€™s work force from 4,500 to 3,000 employees. He said that 450 employees were laid off earlier this year.

ATK Aerospace builds the giant solid-rocket motors for the space shuttle and also has worked on a number of other space, ICBM and missile defense programs.

The company is under contract to build the solid-rocket motors for NASAโ€™s planned Ares rockets, which are based on the shuttle hardware. But those vehicles, along with the rest of NASAโ€™s Moon-bound Constellation program, have been targeted for termination by the White House.