NASA has awarded a multibillion-dollar contract to Lockheed Martin Corp. to design, develop and test a manned spaceship to replace aging U.S. space shuttles, two congressional sources familiar with the decision told Reuters on Thursday. NASA was scheduled to announce the winning contractor at 4 p.m. EDT (2000 GMT). Also competing was a team made up of Northrop Grumman Corp. and Boeing Co. "It's Lockmart," one congressional staff member said, using industry short-hand to refer to Bethesda, Maryland-based Lockheed Martin, and citing a briefing for congressional staff. A second congressional source confirmed Lockheed was the winner. Thomas Jurkowsky, a Lockheed spokesman, would only say: "We're awaiting the 4 p.m. announcement by NASA." Shares of Lockheed Martin briefly topped $83 a share in late afternoon trading on the New York Stock Exchange, then fell back to $82.50, up 24 cents for the trading session. The precise value of the contract was not immediately available. An industry official familiar with the project put the value of the initial deal at roughly $4 billion for the design, development, testing and engineering of the spacecraft. Other sources have said it could be more than double that. The new capsule-style spaceships, dubbed Orion, will replace the U.S. space agency's three remaining space shuttles, which will be retired in 2010 upon completion of the half-built International Space Station. The Orion project is expected to eventually return Americans to the moon, according to NASA's plan.