A Falcon 9 SpaceX rocket stands ready for a sunset launch from complex 40 at the Cape Canaveral Air Force Station in Cape Canaveral, Fla., on Sunday. It will be carrying aloft the DSCOVR satellite. John Raoux/AP hide caption

itoggle caption John Raoux/AP

In an image provided by NASA, astronaut Randy Bresnik prepares to enter Boeing's CST-100 spacecraft for an evaluation at the company's Houston Product Support Center. NASA awarded Boeing with a $4.2 billion contract Tuesday. AP hide caption

itoggle caption AP