Nasa unveils new launcher design
Washington - Nasa unveiled its design selection on Wednesday for a massive new launcher capable of powering manned space flights well beyond low-Earth orbit and ultimately to Mars.
Nasa chief Charles Bolden made the announcement of the design for the new Space Launch System, which the space agency touted as the most powerful rocket since the Saturn V rocket put US astronauts on the moon.
"President Obama challenged us to be bold and dream big, and that's exactly what we are doing at Nasa," said Bolden.
"While I was proud to fly on the space shuttle, tomorrow's explorers will now dream of one day walking on Mars."
The launcher, which will take until 2017 to build and cost an estimated $35bn, will fill a gap in US manned flight programme created by the retirement of the last US space shuttle in July.
But Nasa said it will be far more powerful, capable of carrying much larger payloads beyond low-Earth orbit deep into space, and eventually to Mars.
Still, the so-called "Space Launch System" borrows heavily from the space shuttle, said John Logsdon, the former director of the Space Policy Institute at George Washington University.
For instance, the first stage of the new launcher will use the shuttle's cryogenic engine fuelled with a mix of hydrogen and oxygen kept at very low temperatures, he said.
The system will be topped with a capsule initially capable of carrying into space payloads of 70 to 100 tons, and expanded over time to carry up to 130 tons.
"The booster will be America's most powerful since the Saturn V rocket that carried Apollo astronauts to the moon and will launch humans to places no one has gone before," Nasa said in a statement.
"The SLS will carry human crews beyond low-Earth orbit in a capsule named the Orion Multi-Purpose Crew Vehicle," Nasa said.
The first test launch is scheduled for 2017 followed by manned flights in 2021.
Nasa could use it for a mission to an asteroid in 2025. The agency has indicated that it expects to send astronauts around Mars before eventually landing on the red planet, but not before 2030.