Engineer studies net-shooting robots that corral space debris

BUFFALO, N.Y. — University at Buffalo researcher Eleonora Botta studies how to prevent space debris from crashing into each other or from falling uncontrollably down to Earth.

An assistant professor of aerospace engineering, she was recently awarded a $175,000 National Science Foundation grant to examine how to best utilize robot tether systems to corral some of the 27,000 pieces of debris that NASA tracks.

Many of these space-cleaning-systems call for using nets – imagine a satellite shooting a web, like Spiderman – to capture and control debris.

“The idea is that, after a piece of space debris is captured, it is tugged to a disposal orbit by the active spacecraft where the tether is deployed from,” says Botta. “For objects in low-Earth-orbit, the disposal orbit would be such that the capture piece of debris would re-enter and burn up in the Earth’s atmosphere,” Botta says.

The idea is not new. Both Japan and the European Space Agency have launched satellites with similar missions. However, none have proved especially effective. And given the 20-ton Chinese booster rocket that crashed down on Earth in May, it’s easy to see why Botta’s work is important.

“One of the advantages of actively capturing and de-orbiting large pieces of debris is that their re-entry trajectory is controlled and can be chosen such that, in case some piece of debris survived the re-entry, it would splash down in the ocean with extremely low probability of causing any casualties,” she says.

For the grant, Botta will use powerful computers to model all components of the robot tether system. That includes a chaser spacecraft with sensors and actuators, controlled reeling mechanisms, the cable and net, as well as targeting and contact dynamics.

She’ll also focus on what happens after the debris is captured. This involves controlling the system, as well as the debris it captures. The latter process – known as “de-tumbling” – essentially means gaining control of an out-of-control object in space.

Additionally, Botta will work on developing simpler, potentially less-expensive systems than what exist or have been proposed.