A View from David Zax
Robot Hedgehogs on a Martian Moon
Phobos’s low gravity could be a key to Mars exploration.
This is a Sega game that I would play. Researchers at Stanford, together with folks at MIT and NASA’s Jet Propulsion Laboratory, have designed a robotic platform that could someday explore the Martian moon of Phobos. The system consists of a mother spacecraft and several spiked, spherical “hedgehogs” that would work together to gather scientific data about Phobos. Melissa Pandika of the Stanford Report has the story.
Before we delve into the tech, why bother exploring a Martian moon to begin with? Shouldn’t the main event be exploring Mars itself? Perhaps, but exploring Mars–particularly with humans–presents challenges of its own. Mars is relatively massive, meaning it has relatively high gravity–making it difficult to escape the planet after landing there. But if Phobos should turn out to have originated from Mars, astronauts could land there instead, conduct most of the same studies, and still make their escape. (Phobos’s gravity is 1/1,000th that of Earth, says Gizmag.) The moon could in turn serve as a kind of staging ground for further missions to Mars proper.
That low gravity, though, can be a double-edged sword. It’s difficult for rovers to operate in very low gravity, for instance. The hedgehog design manages to get around this problem in a novel way. Instead of wheels, says Pandika, the rovers have “three rotating discs enclosed within each hedgehog, with each disc pointing in a different direction.” Those spinning discs create inertial forces that should be able to help the robots maneuver nimbly around Phobos.
Unfortunately, as with anything else cool and space-related, the usual disclaimer applies: don’t hold your breath. Pandika says the Phobos Surveyor mission “could” take place–sometime in the next two decades. Still, some researchers–especially a fellow named Marco Pavone–are taking this very seriously. Two generations of prototypes have already been made; there’s work on a third. The mission itself, if it ever does take place, would take three years–including two just to get to Phobos to begin with.
For more recent coverage on Mars, see “Destination: Mars,” which illuminates further the JPL-MIT relationship.