After a 13-day mission, NASA's space shuttle Discovery landed in Cape Canaveral today for the final time. Discovery leaves behind a historic legacy, having made 39 space missions and travelling more than 148 million miles. It has carried nearly 250 crew members in the past 27 years. NASA has two remaining shuttle missions in the works. The Endeavour, which will be commanded by Rep. Gabrielle Giffords's husband Mark Kelly, will launch April 19, and the Atlantis will launch in June.