Washington, Sep 1 (DPA) Lockheed Martin won the first major contract for a new era of US space exploration, kicking off an ambitious effort to return humans to the moon and one day launch them to Mars.

NASA, the US space agency, chose the US aerospace giant over a rival team of Boeing and Northrop Grumman Corp to build the crew capsule for the next generation of spaceships, which will replace the space shuttle fleet slated to be retired in 2010.

The contract is worth up to $8.1 billion over the next 13 years -- a small fraction of the $230 billion NASA is seeking for new initiatives.

"Today we begin a new journey of discovery," Scott Horowitz, a senior NASA space exploration official, told reporters here.

The design of the Orion capsule is the first step in a vision outlined in January 2004 by US President George Bush to send four astronauts to the moon by 2020 - five decades after the first moon walk on July 20, 1969.

Orion's first flight is due by 2014, but NASA chief Michael Griffin has said he would like to launch the new spacecraft several years earlier.

With Russia, China and Japan now competing in the space race, NASA wants to avoid a lengthy gap in launch capability between the shuttle's retirement and Orion's debut.

In Bush's effort to revive the Cold War era fascination with human space exploration, the moon would eventually be a launching pad for Mars missions.

But much of Bush's high-flying plan depends on whether the US Congress will approve the huge sums required to make it work, estimated at $230 billion dollars over 20 years.