Space exploration drones could roam the solar-system's celestial bodies

As a way to explore the surface of low gravity celestial objects like asteroids or concretely the small Martian moon Phobos, Stanford researchers in collaboration with NASA JPL and MIT have designed an autonomous robotic platform that involves a mother spacecraft deploying one or several spiked, roughly spherical rovers.

Measuring about half a meter wide, each rover would hop, tumble and bound across the cratered, lopsided moon, relaying information about its origins, as well as its soil and other surface materials by employing onboard microscopes and other instruments.

The project is being developed by Marco Pavone, an assistant professor in Stanford's Department of Aeronautics and Astronautics. The "mothership" is actually quite tiny with the size of a coffee-table, and called Phobos Surveyor. The vehicle, flanked by two umbrella-shaped solar panels, would orbit around Phobos throughout the mission. The researchers have already constructed a prototype.

The Surveyor would release only one hedgehog at a time. Together, the mothership and hedgehogs would work together to determine the hedgehog's position and orientation. Using this information, they would map a trajectory, which the mother craft would then command the hedgehog to travel.

The explorers would then relay scientific measurements back to the Phobos Surveyor as soon as they are ready. Based on their analysis of the data received from the mothership, scientists would set the next hedgehog deployment site.

A complete mission to Phobos, with 6 hedgehog drones, would last two to three years. Just flying to Phobos would take the Surveyor about two years, and the initial reconnaissance phase, during which the Surveyor would map the terrain, would last another few months.

For many decisions, Pavone's system renders human control unnecessary. "It's the next level of autonomy in space," he said. "It's a piece of technology that's needed before any more expensive type of exploration is considered," Pavone said of the spacecraft-rover hybrid. "Before sampling we need to know where to land. We need to deploy rovers to acquire info about the surface."

For now, the project is still in an early planning stage and far off actual deployment. But the trend is clear, towards ever increasing automatisation both on earth and in space, and it can be assumed that the space hedgehogs, or similar siblings, will eventually roam the solar-system, to explore and in search of rich asteroids worth mining.