NASA orbiter embarks Wednesday on its last mission to International Space Station.
NASA resumed the countdown to shuttle Discovery's final voyage early Monday after repair crews fixed a leaky helium line over the weekend. Discovery is now set to lift off from Florida's Kennedy Space Center at 3:52 p.m. EDT on Wednesday to begin an 11-day mission to the International Space Station.
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Space Shuttle Discovery
Weather forecasters are calling for a 70% chance of favorable conditions at launch time.
The shuttle was originally scheduled to fly Monday, but space agency officials scrubbed the plan after the leak was detected. Discovery's current launch window, the period during which the craft is in position to dock with the ISS, runs through Sunday.
If it goes as planned, Wednesday's launch will mark Discovery's last flight.
The orbiter entered service in 1984, and is the oldest vehicle in NASA's existing shuttle fleet, which also includes Atlantis and Endeavour. The shuttle program is expected to end in February when Endeavour takes to the skies for the final time.
President Obama earlier this year ordered NASA to turn over low-orbit flights to private contractors and focus more on deep space missions and research.
Discovery will carry a six-member, all-U.S. crew on its final voyage, officially known as STS-133. The team is led by Commander Steve Lindsey, 50, of Temple City, Calif., and pilot Eric Boe, 45, of Atlanta. Also on board will be mission specialists Alvin Drew, 47, of Washington, D.C., Tim Kopra, 47, of Austin, Texas, Michael Barratt, 51, of Camas, Wash., and Nicole Stott, 47, of Clearwater, Fla.
Upon achieving orbit, Discovery will execute a series of positioning maneuvers prior to docking with the ISS, where the crew will drop off various parts and supplies. Mission specialists Drew and Kopra will also undertake a pair of six-hour spacewalks during the mission. Stott, meanwhile, plans to broadcast regular mission updates through her Twitter account, @Astro_Nicole.