Someday, human explorers might momentously discover fossils on Mars, proving that the Red Planet once supported extraterrestrial life. An interplanetary expedition of this sort will have overcome major obstacles, such as spacecraft design and the rigors of a many-month voyage. Yet a more subtle challenge to this hypothetical mission's success must, too, be addressed: astronauts will have to perform effective field work while clad in airtight, probably unavoidably cumbersome spacesuits.

The limitations that spacesuits place on their wearers became evident during the Apollo missions. Astronauts found they tired easily and that ordinary tasks took far longer. Due to limited consumables—chiefly, oxygen—the astronauts had to work under severe time constraints, making careful, detailed scientific field study on the Moon that much harder.

"When you go and do something on another world in a spacesuit, it's not just more energy involved, it's time as well. Activities are harder and take longer," said David Willson, who studies spacesuit operations at NASA's Ames Research Center in Moffett Field, Calif.

That's what robotic field assistants are for. To read more, click here.