Retirement

NASA's current plans call for the Space Shuttle to be retired from service in 2010, after nearly 30 years of service. Atlantis will be the first of NASA's three remaining operational Space Shuttles to be retired as the program winds down.^[43] To fill the void left by the Shuttle's retirement, a new spacecraft is being developed to ferry not only passengers and cargo to the ISS but also to travel beyond Earth orbit to the Moon and Mars.^[44] Originally called the Crew Exploration Vehicle, the concept has evolved into the Orion spacecraft and the project has been dubbed Project Constellation. This next-generation vehicle is targeted for first manned launch in 2014 at the earliest. Therefore, all crews traveling to and from the International Space Station during the intervening period will have to do so on board Russian spacecraft or possibly an American commercial spacecraft (see below).

Congress is discussing the possibility of delaying the retirement of the Space Shuttles. One proposal, which would cost about $10 billion, would have the shuttles make six or seven additional flights between 2010 and 2013 and would accelerate development of the Orion ships to be ready by then. A second proposal would keep the shuttles flying until 2015 and leave Orion's schedule intact.^[45]

Commercial replacement vehicles and services

NASA announced the awarding of contracts for the cargo resupply of the International Space Station (ISS) to SpaceX and Orbital Sciences Corporation on December 23, 2008.^[46] SpaceX will use its Falcon 9 launch vehicle and Dragon spacecraft.^[47] Orbital Sciences will use its Taurus II launch vehicle and Cygnus spacecraft.