ATLANTA (CNN) -- NASA has awarded Lockheed Martin the contract to build the Orion spacecraft, which is to be used in the effort to return astronauts to the moon.

Lockheed Martin Corp.'s (Charts) contract to design and develop a new manned spaceship was estimated at $3.9 billion through 2013, NASA said, according to Reuters.

3-D rendering of the Orion crew exploration vehicle in lunar orbit, with the Earth in the background.

Also competing was a team made up of Northrop Grumman Corp. (Charts) and Boeing Co. (Charts)

"Both proposals were sound, they were carefully prepared," Doug Cooke, a NASA official, told reporters at a news conference. "We think we're picking the right contractor - we know we are."

The multibillion-dollar program is also designed to replace the space shuttle. The Orion will be designed to carry a crew of up to six astronauts, along with cargo, to the International Space Station and return cargo to Earth, according to Skip Hatfield, the Orion project manager.

Hatfield said the spacecraft - which looks similar to Apollo spaceship that first carried astronauts to the moon - will be built in four main elements, reaching 66 feet long.

The top element, he said, is a launch-abort system that would pull the crew free of the rest of the rocket in the event of a major problem during launch. The second element is the crew module itself, which includes a replaceable heat shield on the back for return-to-Earth flights and the docking port on the nose.

The third section is the service module: "a big service station, if you will," Hatfield said. The final section is the "spacecraft adapter," which connects the craft to the rocket boosters.

In addition to its space station and moon missions, Orion is projected someday to carry astronauts to Mars.

From staff and wire reports

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