Astronauts are training underwater to test tools for exploring an asteroid as well as the type of spacesuit that might be worn on the mission, according to the US space agency.
Wearing modified versions of the orange space shuttle launch and entry suits, two astronauts went underwater last week, in the Neutral Buoyancy Laboratory at NASA's Johnson Space Center, a 40-feet-deep swimming pool that helps provide the lack of gravity needed for astronauts to practice for spacewalks.
There a mockup of the Orion spacecraft that will carry astronauts to the asteroid, docked to a mockup of the robotic spacecraft that will be used to capture an asteroid and bring it into a stable orbit near the moon, provided the backdrop for the simulated spacewalk.
"We're working on the techniques and tools we might use someday to explore a small asteroid that was captured from an orbit around the sun and brought back by a robotic spacecraft to orbit around the moon," said Stan Love, one of the astronauts participating in the tests.
"When it's there, we can send people there to take samples and take a look at it up close. That's our main task; we're looking at tools we'd use for that, how we'd take those samples," Love said.
One of the primary goals of visiting an asteroid will be to obtain a core sample that shows its layers, intact - such a sample could provide information on the age of the solar system and how it was formed.
But the tools geologist use to collect core samples or even chips of rocks aren't a good idea in space - swinging a hammer in front of your face isn't safe when the sheet of glass between you and it is necessary to keep you alive, NASA said in a statement.
Love and astronaut Steve Bowen tried out a pneumatic hammer to give them a feel for whether a battery-powered version might be useful.
They also evaluated a version of the spacesuit that could be worn on an asteroid. Orion astronauts already needed a launch and entry suit to protect them during the most dynamic phases of their flights.
So, rather than add to the weight Orion has to carry into orbit and take up additional space inside the crew module, engineers have been working to turn the shuttle-heritage Advanced Crew Escape Suit - or ACES - into something suitable for spacewalks.
NASA is already working to identify an asteroid that could be reached by a robotic mission to capture it and bring it into a stable orbit around the moon.
Once it's there, the Orion spacecraft and Space Launch System rocket will launch a crew of astronauts to explore it and gather samples.