CAPE CANAVERAL, Florida, May 23, 2009 (AFP) - NASA further delayed Saturday the return to Earth of the space shuttle Atlantis and its seven-man crew because of poor weather.
|Canadian astronaut Robert Thirsk (L) waves during a training session at the Russian-leased Baikonur cosmodrome, in Kazakhstan, on May 23, 2009 (AFP photo)|
Attempts to land the shuttle, following a successful mission to repair the Hubble telescope, had to be completely abandoned on Friday because of inclement conditions at the Kennedy Space Center in Florida.
NASA said it had decided not to use the first window of opportunity on Saturday, scheduled for 9:16 am (1316 GMT), for the same reason.
The US space agency has prepared Edwards Air Force Base in California as a back-up landing point in case conditions do not clear up in Florida.
Saturday still holds two more chances to land at the Kennedy Space Center and one opportunity to bring Atlantis to Edwards, NASA officials said.
NASA would prefer to land the shuttle in Florida as it would cost the agency some two million dollars (1.4 million euros) extra to get the craft back home from California.
Atlantis is returning to Earth after conducting crucial repairs on the Hubble Space Telescope.
On Friday, astronauts flying 500 kilometers (311 miles) above Florida saw what awaited them on Earth: cloudy skies, strong winds and possible thunderstorms.
Atlantis, which blasted off on May 11, saw two landings cancelled on Friday. The final decision to cancel Friday's return was made about two hours before the shuttle was due to land.
"They have enough supplies to stay on board until Monday. But we don't like to wait until the last moment," said NASA spokesman Allard Beutel.
NASA has set several conditions for a landing: the cloud cover in the skies must not be more than 50 percent, visibility must be at least eight kilometers (five miles) and lateral winds must not be blowing at more than 28 kilometers an hour (17 miles an hour).
Atlantis and its seven-strong crew have completed a successful 11-day mission to repair and restore the Hubble space telescope to allow it to continue its ground-breaking exploration of the universe for at least another five years.
As early as Thursday, the astronauts were told by NASA to shut down some of the computers on board the shuttle to conserve electricity in the event that their landing was delayed.
The Hubble observatory was released on Tuesday after five obstacle-filled spacewalks.
The enhancements have equipped Hubble to search for the earliest galaxies, probe the mysteries of dark matter and dark energy as well as study planet-making processes.
But the trouble was well worthwhile.
John Grunsfeld, an astronomer turned astronaut who led three of the mission's five spacewalks, told US lawmakers Thursday that Hubble "is probably the most significant science instrument of all times" that "has struck a chord in human hearts around the world."