Biggest-Ever Rocket Will Take Man To Mars

Nasa has unveiled the biggest rocket in history which is capable of taking six astronauts to Mars.

The new Space Launch System (SLS) will have a maximum payload that could top 165 tons - dwarfing the space shuttles' 27 tons.

Artists' impressions revealed to members of Congress in Washington show the design is a return to the shape of the Saturn V rockets that carried Apollo astronauts to the moon.

And like the Saturn rockets, it will be fuelled by safer liquid oxygen and hydrogen. The shuttle used solid boosters, which cannot be turned off once they have been ignited.

"It's back to the future with a reliable liquid technology," said Professor Scott Hubbard, a former Nasa official who investigated the 2003 space shuttle Columbia disaster.

The launcher will have a module design so the rockets of different sizes can be constructed to meet the demands of individual missions.

Unmanned test flights could start in 2017, with the first crew flying in 2021. A mission to a nearby asteroid could follow in 2025, and Mars in the 2030s.

Nasa administrator, and former astronaut, Charles Bolden said: "President Obama challenged us to be bold and dream big, and that's exactly what we are doing at Nasa.

"While I was proud to fly on the space shuttle, tomorrow's explorers will now dream of one day walking on Mars."

The new rocket programme is expected to cost US taxpayers \$35bn (£22bn).

Since retiring the shuttle earlier this year, Nasa has commissioned commercial companies to design and operate cargo rockets to service the International Space Station.

It will concentrate its own resources on deep space exploration.