There, the combined gravity of Earth and the moon would tug on a spacecraft with exactly the force needed for it to hover near the moon without spending fuel. Putting a spaceport at the Earth-moon Lagrange point 2 (EML-2) might assist human missions to an asteroid or to Mars – both on the list of NASA goals Obama announced in 2010.
Buzz about NASA’s vision for an EML-2 outpost has been swirling since September, when the Orlando Sentinel newspaper obtained documents detailing how such a craft could be built using parts left over from the International Space Station.
NASA has probably already cleared plans for the craft with the Obama administration, space policy expert John Logsdon of George Washington University in Washington DC told Space.com on 7 November, and has been waiting until after the election to announce them.
Asked about the spaceport, NASA officials would only say the agency is working towards sending a capsule to loop around the moon in 2017 and a manned mission to lunar orbit in 2021.
The president’s plan
“NASA is executing the President’s ambitious space exploration plan that includes missions around the moon, to an asteroid and eventually to Mars,” spokesperson Rachel Kraft said in an email to New Scientist. “There are a variety of routes and options being discussed to help build the knowledge and capabilities to get there, and other options may be considered as we look for ways to buy down risk.”
The hovering moon base plan sounds plausible, although NASA will probably wait until the new federal budget is announced in February to confirm anything, says Dan Lester of the University of Texas at Austin, who has served on NASA policy committees.
“With all these rumours, I haven’t heard anybody at NASA who’s denying it. I think that says a lot,” he says.
EML-2 is farther from Earth than astronauts have ever ventured, and is not shielded from radiation by Earth’s magnetic field. That makes it a good testing ground for deep space life-support systems, Lester says.
“If you want to get people out of low-Earth orbit, you want to test how well they can do in deep space, and you want to have some useful things for them to do when they’re out there, maybe the first thing to do is to send them to a Lagrange point rather than sending them to an asteroid,” he says.
Scuba on Titan
An EML-2 spaceport could also allow astronauts on the base to explore the moon using robots controlled in real time. The three-second delay for radio signals to travel round-trip between Earth and the moon makes directly controlling a lunar rover from our home planet impractical. “It’s as if you were driving drunk,” says Lester. But EML-2 is close enough to the moon to erase that obstacle.
Last week NASA completed a test of such technology when an astronaut on the International Space Station drove a toy rover on Earth via the agency’s interplanetary internet.
Similar strategies could be used on Mars, as either a prelude to or a substitute for landing humans on the surface. Having a telepresence in space could also take human minds to places where our bodies can’t go.
“We could send human beings into orbit around [Saturn’s moon] Titan and they could do virtual scuba diving in the methane lakes,” Lester says. “When you think about doing exploration that way, all of a sudden there are many more destinations for human spaceflight than there were before.”
Syndicated content: Lisa Grossman, New Scientist