CORINNE, Box Elder County — A train carrying NASA's last space shuttle solid rocket boosters left ATK last week and should arrive at Florida's Kennedy Space Center in a few days.

The space shuttle is slated to retire this year, with only two missions left. NASA and ATK senior managers plan to board the train in Jacksonville, Fla., for the final leg of the trip to Kennedy.

The solid rocket booster segments will be used for the shuttle Atlantis for what is currently planned as the "launch on need," or potential rescue flight, for the final shuttle mission — that of Endeavour's STS-134, which is targeted to launch no earlier than mid-November.

The eight train cars carrying the booster segments left ATK's railyard at Corinne and will be available for viewing by the media on Thursday, May 27, at NASA's "Jay Jay" railroad yard.

Even as the space shuttle program is winding down, ATK is building the five-segment first stage of the "next-generation" rocket, the Ares 1, and has all five segments in the test stand for a ground test planned in September.

Due to the phasing out of the space shuttle program, ATK announced a fourth round of layoffs involving 247 workers last week. Since last April, a total of 1,500 workers have been let go.

The company has been building solid rocket boosters since the inception of the space shuttle program 30 years ago.

— Amy Joi O'Donoghue