Thisstory was updated at 10:40 a.m. EDT.
CAPECANAVERAL, Fla. - Astronauts aboard the space shuttle Atlantis are headed hometo land on a backup runway in California after bad weather thwarted earlierattempts to land in Florida.
Theastronauts are now set land at 11:39 a.m. EDT (1539 GMT) at the Edwards AirForce Base in California to end a 13-day mission that gave the iconic HubbleSpace Telescope one lastservice call. Rain showers within 30 miles of the shuttle?s landing striphere at NASA?s Kennedy Space Center prevented landing attempts earlier today,as well as on Friday and Saturday.
Afterclinging to hope the weather would improve in Florida, entry flight directorultimately opted to send Atlantis in California, where conditions are clear fora shuttle landing.
?TheEdwards weather is great,? Mission Control radioed the Atlantis astronauts,adding that they should have clear skies and good communications all the home.
?Copy that,?Atlantis commander Scott Altman replied. ?A beautiful day in the desert.?
Atlantisfired its twin rocket engines at about 10:24 a.m. EDT (1424 GMT) to begin thedescent back to Earth.
Altmanand his crewafter overhauling the Hubble Space Telescope for the last time. The shuttle launchedtoward the 19-year-old space telescope on May 11.
Set toreturn to Earth with Altman are shuttle pilot Greg C. Johnson and missionspecialists Michael Good, Megan McArthur, John Grunsfeld, Michael Massimino andAndrew Feustel.
During fiveback-to-back spacewalks, Atlantis astronauts installed two powerful newinstruments, replaced aging gyroscopes and batteries, and repaired a pair oflong-broken instruments that were never designed to be fixed in space.
The orbitalwork is expected to extend Hubble?scosmic vision and life for at least five or 10 years. The astronauts alsoinstalled a docking ring on Hubble that will allow a robotic spacecraft tolatch on sometime after 2020 and sent it plunging into the Pacific Ocean to endits mission.
The missionis NASA?s fifth and final flightto Hubble and cost about $1.1 billion. In all, about $10 billion has beeninvested in Hubble since its inception.
SPACE.comis providing continuous coverage of NASA's last mission to the Hubble SpaceTelescope with senior editor Tariq Malik in Cape Canaveral, Fla., and reporterClara Moskowitz in New York. Click here for landingcoverage, mission updates and SPACE.com's live NASA TV video feed.Live coverage begins at 6:30 a.m. EDT.
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