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 July 1 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 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 was slated to launch its experiment payload, called the Alpha Magnetic Spectrometer, no earlier than Nov. 27.

The next available launch date for Endeavour is Feb. 26, 2011, NASA officials said.

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.

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 also is considering adding a shuttle flight, a June 2011 mission during which Atlantis would deliver cargo and supplies to the orbiting lab. NASA needs approval from the White House by August to begin planning the mission.