This story was updated at 1:04 p.m. ET.
NASA's space shuttle fleet will continue flying through at least early next year due to delays with the agency's final two missions.
Space shuttle program managers officially decided Thursday to delay the launch of NASA's next space shuttle mission to Nov. 1 and push back the last scheduled flight to late February 2011.
The move was not unexpected ? the space agency said in late June it was hoping to postpone the final shuttle flights because of cargo delivery and schedule conflicts. Both missions are bound for the International Space Station.
The new plan delays the launch of Discovery ? NASA's oldest space shuttle ? from an earlier Sept. 16 target to Nov. 1.
Discovery's STS-133 mission is the orbiter's last scheduled flight and will deliver a shuttle cargo pod refitted to serve as a permanent storage closet for the space station. The shuttle will also deliver Robonaut 2, a prototype robot designed to assist astronauts working in space.
Delays preparing Discovery's cargo for launch forced mission managers to push the launch date back. That shift forced another delay with NASA's final space shuttle mission on the schedule ? the launch of Endeavour to deliver a $1.5 billion astrophysics experiment to the space station.
Endeavour is NASA's youngest space shuttle and was slated to launch its experiment payload, called the Alpha Magnetic Spectrometer, no earlier than Nov. 27. But because Discovery's flight is delayed, so too is Endeavour's STS-134 mission.
The next available launch date for Endeavour is Feb. 26, 2011, NASA officials said in a statement.
Launch slips for NASA's last space shuttle missions were anticipated by more than just mission managers.
In February, President Barack Obama included $600 million for NASA's space shuttle program as part of the agency's fiscal year 2011 budget proposal. The funds were set aside in case NASA needed to delay its final shuttle flights beyond their planned September 2010 retirement date.
A report issued in March by NASA's Office of the Inspector General also predicted that the space agency would have to fly some if its final shuttle missions in 2011.
NASA typically spends about $200 million a month to keep its space shuttle fleet flying, though agency officials have said they have enough funding in place to support operations through February 2011.
NASA is still waiting to hear from the White House if the space shuttle Atlantis ? the current middle child of the U.S. orbiter fleet ? will get a chance fly one more mission.
Atlantis flew its 32nd and final scheduled mission in May to deliver a new Russian room to the International Space Station. NASA is hoping to get a chance to launch the shuttle one more time in June 2011 to deliver cargo and supplies to the orbiting lab. [Photos: Last Launch of Shuttle Atlantis]
But to give Atlantis one extra shuttle flight, NASA needs approval from the White House, which it does not yet have, by August to begin planning the mission.
NASA is retiring its space shuttle fleet after 30 years of service to make way for future programs aimed at sending astronauts to visit an asteroid by 2025, then target missions to Mars.
The plan is part of President Obama's new space exploration proposal, which also includes the cancellation of NASA's Constellation program developing new rockets and spaceships slated to send astronauts back to the moon.
Once the space shuttles retire for good, NASA will rely on Russia's Soyuz spacecraft to ferry astronauts to and from the space station until American commercial spaceships become available.
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