CAPE CANAVERAL, Fla. Stormy weather prevented space shuttle Atlantis from landing on its first try Sunday, and NASA directed the astronauts to take an extra swing around the world before coming down, quite possibly to California.
It was the third day in a row thunderstorms thwarted NASA's plans to bring the astronauts home and end their exalted Hubble Space Telescope repair mission.
"The weather is looking good," Mission Control radioed. "But not good enough for us to get comfortable."
NASA still hoped for a lucky break in the weather, but the chance for thunderstorms at Kennedy Space Center was expected to increase as the morning wore on. Out at Edwards Air Force Base in California, the backup landing site, conditions were considered ideal.
"We're going to keep both options open," Mission Control told commander Scott Altman.
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 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 effort, won praise from President Barack Obama and members of Congress. But with space shuttles retiring next year, no more astronauts will visit the telescope. 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.