A banner hanging above Columbia says it all. Photo: Spaceflight Now

Nestled in California's Antelope Valley north of Los Angeles is the birthplace of America's space shuttles, the world's only reusable human spaceships.

Today the veteran shuttle Columbia has returned home to Boeing's Palmdale garage for a year-long tune-up of sorts that will prepare the craft for a new century of space travel.

A $90 million refurbishment effort is underway to install a sophisticated "glass cockpit" and remove sensors not used since the early shuttle test flights nearly 20 years ago.

Columbia's future, however, won't be spent ferrying pieces of the International Space Station into orbit like its sisterships.

Although Boeing technicians have put the $2 billion craft on a diet, shedding about one ton of weight, the shuttle is still too heavy to participate in assembling the $60 billion orbiting laboratory over the next five years.

Instead NASA will use Columbia for other space missions like servicing the Hubble Space Telescope and possibly hauling U.S. military or commercial satellites to the final frontier.