Shuttle to try to land again after 2 days of rain

CAPE CANAVERAL -- Space shuttle Atlantis and its astronauts aimed for a landing Sunday, on one side of the country or the other, after two days of storms delayed the end of their exalted Hubble Space Telescope repair mission.

At sunrise, Mission Control informed the seven crewmembers that the weather at Kennedy Space Center seemed to be a little better. Indeed, the sky looked to be clearing over the landing strip, although flashes of lightning still appeared offshore as they closed the payload bay doors in preparation for descent.

Hoping for a break, flight controllers said they would try to bring Atlantis down at its home base. But if that did not work out, the shuttle was going to be diverted to Edwards Air Force Base in California.

"That's nice to know that Edwards is solid as a backup," commander Scott Altman said.

"Roger, the skies are clear out there in California," Mission Control replied.

After 13 days in orbit, many of them tending to Hubble, Altman and his crew wanted to get back on the ground. They were supposed to return to Earth on Friday, but NASA opted to keep the astronauts circling the world in case the bad weather from a massive low-pressure system eased up.

NASA saves at least a week of work and close to $2 million in ferry costs by landing in Florida.

Although Atlantis had enough supplies to remain in space until Monday, NASA did not want to cut it that close.

The astronauts have left behind a refurbished Hubble that scientists say is better than ever and should keep churning out pictures of the universe for another five to 10 years. They carried out five spacewalks to give the 19-year-old observatory new science instruments, pointing devices and batteries, and fix a pair of broken instruments, something never before attempted. Stuck bolts and other difficulties made much of the work harder than expected.

The $1 billion overhaul was the last for Hubble and, thanks to the crew's valiant effort, won praise from President Obama and members of Congress. But with space shuttles retiring next year, no more astronauts will visit the telescope, and NASA expects to steer it into the Pacific sometime in the early 2020s.

As a souvenir for the masses, the astronauts are bringing back the old wide-field camera they pulled out, so it can be put on display at the Smithsonian Institution. The replacement camera and other new instruments will enable Hubble to peer deeper into the universe, to within 500 million to 600 million years of creation.

It will take almost all summer for scientists to check out all the new telescope systems. NASA expects to release the first picture in early September.

This mission almost didn't happen. It was canceled in 2004, a year after the Columbia tragedy, because of the dangers of flying into a 350-mile-high orbit that did not offer any shelter in case Atlantis suffered damage from launch debris or space junk. The public protest was intense, and NASA reinstated the flight after developing a rescue plan and shuttle repair kits.

Shuttle Endeavour was on standby for a possible rescue mission until late last week, after inspections found Atlantis' thermal shielding to be solid for re-entry. Endeavour now will be prepped for a June flight to the international space station.