Space shuttle Discovery is set to launch Thursday from Cape Canaveral, Florida, for its final flight, ending nearly three decades of space travel.
The six-member crew will deliver a storage module, a science rig and spare parts to the international space station during its 11-day mission.
Originally scheduled for November, Discovery's launch was delayed because of repairs to the external tank's support beams.
NASA, which is winding down the shuttle program, announced the February 24 launch a few weeks ago. It will be Discovery's 39th voyage.
The launch is scheduled for 4:50 p.m. ET at Kennedy Space Center in Florida.
Astronaut Steve Bowen was assigned to take the place of Tim Kopra, who was injured in a bicycle accident, NASA said.
The last scheduled launch of space shuttle Endeavour is currently on for April 19 and shuttle Atlantis is tentatively scheduled to launch during the summer.
The shuttle has spent 352 days in orbit, circling the Earth 5,628 times. It has also carried 246 crew members, more than any space vehicle in history.