Two NASA space shuttles on way to Florida

Columbia had been scheduled to land at another Oklahoma base, but bad weather forced the diversion to Texas. Weather permitting, both were scheduled to continue on to Florida on Friday.

Shuttle Columbia left California first, taking off at 11 a.m. from Palmdale, where it underwent a 17-month major overhaul and upgrade.

Atlantis followed 37 minutes later, taking off from nearby Edwards Air Force Base.

The back-to-back flights were unprecedented.

Atlantis landed at Edwards on Feb. 20 after a 13-day mission to the international space station, Alpha, where the crew delivered and installed Destiny, a $1.4 billion laboratory considered the most sophisticated research module ever to fly in space.

Bad weather over Cape Canaveral, Fla., forced Atlantis to detour to California after the mission rather than returning directly to Florida.

Each cross-country flight atop the modified Boeing 747s costs the National Aeronautics and Space Administration nearly $1 million.

Atlantis is scheduled to return to space on May 17, when it delivers a new airlock to Alpha. NASA plans to launch Columbia in late fall, either on a research mission or on a maintenance flight to the aging Hubble Space Telescope, a NASA spokesman said.

NASA has four space-going shuttles, Atlantis, Columbia, Discovery and Endeavour.<