Space Shuttle program
The Space Shuttle program or officially the Space Transportation System (STS) is the current US manned space program. The first manned flight was STS-1 which was launched on April 12, 1981 and landed on earth a little over 2 days later on April 14, 1981. There have been over 100 space shuttle flights since this first flight. The current fleet of space shuttles is comprised of Discovery, Atlantis, and Endeavour. The space shuttle program is planned to be retired in 2010. The Space Shuttle program will be followed by the manned Constellation program which is currently planned to launch its first manned mission in 2013.