A NASA-funded effort hopes to produce a prototype robot, weighing only about 2 pounds and powered by microbes within the next 10 years.

With the firstyear funding coming from the NASA Innovative Advanced Concepts program, scientists plan to harness microbes as a source of almost endless power for the next generation of robotic explorers, offering an alternative to space missions that rely upon solar or nuclear power.

According to researchers, such microbial fuel could power space robots indefinitely, for as long as the bacteria have the small amount of food needed to stay alive and create electricity through their chemical reactions.

"Whether you're looking at satellites or planetary explorers, to have a power system that's not reliant on the sun of the solar system, day or night cycles, and hazardous materials such as nuclear or other harsh chemicals, means you really open a lot of doors for expanding the duration of scientific missions," said Gregory Scott, a space robotics engineer at the U.S. Naval Research Laboratory.

While the microbial fuel cells cannot power huge robots, it can slowly charge a battery until enough energy exists to power a scientific instrument or move a tiny robot, and be able to keep a small space mission going for as long as necessary.

"The bacterial colony will live as long as you give it food - in our case, sugar - or one of the other biomass fuels we're looking into. The colony will be able to survive pretty much indefinitely," Scott said.

After the researchers are able to build a working prototype robot, they have to study the challenges of sending microbes on missions headed for deep space, asteroids or distant planets, including the question of protecting extraterrestrial surfaces from contamination.

"There are planetary protection concerns, as well as concerns about protecting the microbes themselves from radiation," Scott said. "Sometime down the road we also have to consider whether the microbes we're looking at are most effective for radiation environments or extreme temperatures."