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NASA officials have delayed the launch of the space shuttle Endeavor for at least a day because of cloud cover over the Kennedy Space Center in Florida. The mission comes at a time when President Barack Obama is preparing to abandon the U.S. space agency's effort to return astronauts to the moon by 2020. There are only five missions left for the Constellation program, which began in 1981, before it is scheduled to halt at the end of this year. The shuttle, when launched, will deliver a cupola to outer space which will provide panoramic views of Earth from the International Space Station.