Hedgehog Robots Designed for Phobos Exploration

January 8th, 2013

Courtesy of Stanford Dept. of Aeronautics and Astronautics

Phobos, one of two moons of Mars. Credit: ESA/Mars Express

Phobos, one of the two moons of Mars, might be explored one day by a jumping robotic probe.

Marco Pavone, an assistant professor in Stanford’s Department of Aeronautics and Astronautics, is working on “hedgehogs” – spiked, roughly spherical rovers that hop, tumble and bound across the cratered, lopsided moon, relaying information about its origins, as well as its soil and other surface materials.

Work on the concept was initiated as part of the NASA Innovative Advanced Concepts Program (NIAC).

The mission proposed for Phobos involves a mother spacecraft — known as the Phobos Surveyor — that releases the hedgehogs. While the orbiting craft can take large scale measurements of the Martian moon, the landed hedgehogs might use microscopes to measure the fine crevices and fissures lining the terrain.

Moon mystery

An entire mission would last two to three years.

An initial reconnaissance phase would have the Surveyor orbiter map the terrain, over a few months. The mothership would release each of the five or six hedgehogs several days apart, allowing scientists enough time to decide where to release the next hedgehog.

An analysis of Phobos’ soil composition could uncover clues about the moon’s origin.

Scientists have yet to agree on whether Phobos is an asteroid captured by the gravity of Mars or a piece of Mars that an asteroid impact flung into orbit. This could have deep implications for our current understanding of the origin and evolution of the solar system, Stanford’s Pavone said.

Phobos may be useful in other ways.

If Phobos did indeed originate from the red planet, astronauts landed there could study the moon itself in preparation for a later assault onto Mars. Indeed, an astronaut-tended base station on Phobos would allow crews to operate robots on Mars as well as test technologies for potential use in a human mission to the planet.

By Leonard David