NASA on Thursday awarded Lockheed Martin Corp. a multibillion dollar contract to build a manned lunar spacecraft, agency officials announced.

The space agency chose Lockheed Martin, the biggest government aerospace contractor, to build the Orion crew exploration vehicle. The craft is intended to replace the space shuttles and take astronauts to the moon and perhaps Mars or an asteroid.

NASA’s chief has described the envisioned craft as ‘‘Apollo on steroids,’’ according to the Associated Press. But Lockheed Martin hasn’t built manned spacecraft before.

‘‘NASA decided to do something different and go with a company that has not been in manned space before, sort of spreading the wealth and making sure they’ve got two contractors that know the manned space business,’’ aerospace industry analyst Paul Nisbet, president of JSA Research, told the news agency.

Lockheed has built unmanned craft successfully, and also once disastrously, when a mixup between English and metric measurements made its 1999 Mars Climate Orbiter crash.

“The Orion crew capsule will carry astronauts back to the moon and later to Mars. The first flight with astronauts aboard is planned for no later than 2014. Orion’s first flight to the moon is planned for no later than 2020,” NASA said in a statement.

“Our intent is to keep the destination focusing the design but we are not excluding the possibility of using Orion for other things, such as de-orbiting the Hubble Space Telescope in the 2020s or making a trek to an asteroid,” said Jeff Hanley, who manages the Constellation Program from the Johnson Space Center in Houston.

The contract was open-ended, allowing NASA the ultimate decision on reusability of Orion and landing sites. It is valued at about $3.9 billion for design, development, testing and evaluation of the new spacecraft, NASA officials said. Additional contract options are worth more than $4 billion through 2019.

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