Nasa to send new rover to Mars in 2020

NASA plans to send a new rover to Mars in 2020 as it prepares for a manned mission to the Red Planet, the US space agency said on Tuesday.

The announcement came a day after NASA released the results of the first soil tested by the Curiosity rover, which found traces of some of the compounds like water and oxygen that are necessary for life.

President Barack Obama's administration "is committed to a robust Mars exploration program", NASA Administrator Charles Bolden said in a statement.

"With this next mission, we're ensuring America remains the world leader in the exploration of the Red Planet, while taking another significant step toward sending humans there in the 2030s."

The design of the new rover will be based on Curiosity in order to cut costs and reduce risks of engineering errors.

While the science goals are still fuzzy, NASA said the rover at the very least should kickstart a campaign to return Martian soil and rocks to Earth - a goal trumpeted by many scientists. The current rover lacks that capability.

The new rover brings the number of NASA missions currently operating or being planned for Mars to seven.

The Opportunity rover has been exploring the Martian surface since 2004. The much more sophisticated Curiosity rover landed in Gale Crater on August 6.

Two other spacecraft are currently orbiting Mars to study the planet from above and help relay signals from the rovers.

NASA also plans to send a craft dubbed InSight to dig the planet's depths in 2016 to determine whether the planet's core is solid or liquid like Earth's.

The first spacecraft reached Mars in 1965. Mariner 4 sent back 22 close-up photos of the planet's cratered surface and won the United States the honour of the first successful mission to Mars.

The Soviet Union was the first to successfully land on Mars in 1971, but the Mars 2 failed after relaying 20 seconds of video to an orbiter. Five years later, the United States managed to land the Viking 1 and 2 crafts, which sent back thousands of images and reams of data before they were deactivated.

Most missions to Mars have failed, although there have been a handful of successful projects, including the Pathfinder, which landed in 1997, and the Spirit, which landed in 2004 and roamed the surface for six years before contact was lost.

The $2.5bn nuclear-powered Curiosity is designed to hunt for soil-based signatures of life on the Earth's nearest neighbour and send back data to prepare for a future human mission.