NASA is eking out as much extra flight time as possible for space shuttle Discovery and its crew.
This is Discovery's final voyage and it will now last 13 days.
On Thursday, NASA added another day to the mission, which already had been extended a day. Mission managers want the six shuttle astronauts to help unload the new storage unit that was delivered to the International Space Station by Discovery. They will continue the work Friday.
Discovery will remain at the space station until Monday. Landing is now scheduled for Wednesday.
NASA's most traveled shuttle will end its career with a total of 365 days spent in space.
President Barack Obama gave thanks Thursday to all those who have worked on Discovery.