Backdropped by a cloud-covered part of Earth, Space Shuttle Discovery (STS-128) is featured in this image photographed by an Expedition 20 crew member on the International Space Station soon after the shuttle and station began their post-undocking relative separation on Sept. 8, 2009.
This story was updated at 4:02 p.m. EDT.
NASA has ordered astronauts aboard space shuttle Discovery to switch to a backup runway in California for their planned landing Friday due to persistent storms in Florida that made a return to their home port impossible.
Discovery had two chances to set down today on its primary runway at the Kennedy Space Center (KSC) in Florida, but thunderstorms near the shuttle?s landing strip kept the spacecraft at bay. The astronauts now hope to land at 8:53 p.m. EDT (0053 Sept. 12 GMT) at the Edwards Air Force Base in California.
?We do appreciate everybody that worked the weather so hard in Florida and we appreciate the families making the trip down,? shuttle commander Rick Sturckow radioed Mission Control after hearing the news. ?But it doesn?t look like it?s going to work out for today so we?ll set up for Edwards.?
Discovery is returning to Earth to end a 14-day delivery mission to the International Space Station. The astronauts delivered a new crewmember to the station, as well as tons of supplies and science gear for the outpost?s six-person crew.
Shuttle entry flight director Richard Jones activated the backup runway at the Edwards Air Force Base in California for today?s landing attempts, giving Discovery a total of four tries (two in Florida and two in California) because weather conditions at both sites were expected to deteriorate on Saturday.
NASA prefers to land space shuttles in Florida when possible because it is the orbiter fleet?s home port. Florida landings also avoid the extra week of transport time and $1.8 million in turnaround costs required to ferry shuttles home from California for their next mission. Discovery is due to fly to the space station again early next year to deliver more supplies.
Discovery launched late Aug. 28 and left the station with enough supplies to last through February. Among the major delivery items were an air-scrubbing device, a new astronaut bedroom, a pair of powerful science experiment racks and a treadmill named after TV comedian Stephen Colbert.
The treadmill was named after the comedian host of Comedy Central?s ?The Colbert Report? as a consolation prize after he won the naming rights to a new space station room in an online poll earlier this year. NASA opted to name the new room Tranquility after the Apollo 11 moon base, but rechristened the treadmill the Combined Operational Load Bearing External Resistance Treadmill (COLBERT) for Stephen Colbert. The exercise gear is in more than 100 pieces and will be assembled by station astronauts later this month.
Returning to Earth on Discovery with Sturckow will be pilot Kevin Ford and mission specialists Danny Olivas, Jose Hernandez, Patrick Forrester, Tim Kopra and Christer Fuglesang - a Swedish astronaut representing the European Space Agency.
Kopra is returning home after nearly two months aboard the station and is bringing home Buzz Lightyear, a 12-inch Disney toy that has been in orbit for 15 months as part of an educational program. A tickertape parade at Walt Disney World in Florida awaits Lightyear upon his return to Earth.
- Image Gallery - Shuttle Discovery's Midnight Launch
- Video - Stephen Colbert to NASA: 'No Chubby Astronauts'
- SPACE.com Video Show - The ISS: Foothold on Forever
SPACE.com is providing complete coverage of Discovery's STS-128 mission to the International Space Station with Managing Editor Tariq Malik and Staff Writer Clara Moskowitz in New York. Click here for shuttle mission updates and a link to NASA TV.