File photo of space shuttle Discovery lifts off from the Kennedy Space Center in Cape Canaveral

 
File photo of space shuttle Discovery lifts off from the Kennedy Space Center in Cape Canaveral
Space shuttle Discovery lifts off from the Kennedy Space Center in Cape Canaveral, Florida, in this February 24, 2011 file photograph. Discovery, which completed its final mission last month, will go to the Smithsonian National Air and Space Museum's Udvar-Hazy Center in northern Virginia to retire, the NASA space agency said April 12, 2011. REUTERS/Pierre Ducharme/Files (UNITED STATES - Tags: SCI TECH)