For a terrestrial civilization, we sure have made a whole bunch of space trash, including approximately “22,000 objects larger than the size of a softball,” and a bunch smaller than that, most of which come from old satellites (can we start a cosmic recycling program for these?) If you’ve seen Gravity you know how dangerous space trash can be, it can also essentially multiply as it continues colliding. The problem is that it’s not clear whose responsibility it is to clean this mess up, given that waste collection and disposal services don’t exactly make it out that far. It’s also dangerous to collect this trash, as objects can move quick and crazy in space. Researchers at MIT have now developed an algorithm to help crews anticipate the movement of space junk so they can more easily snatch it up.
The technique was recently tested at the ISS where astronauts used SPHERES (Synchronized Position Hold Engage and Reorient Experimental Satellite) satellites, which are devices for testing various technologies in zero gravity. The SPHERES are pretty ingenious—they behave like satellites, so they’re the perfect proving ground, and they’re also small enough to actually be tested inside the ISS, which is what they did here. Astronauts equipped a SPHERE with a couple of linked cameras that filmed another satellite that was spinning around in the air.
In the video above, you can see the footage, as well as the algorithm MIT researchers developed. The procedure uses images from both cameras in much the same way we use images from both eyes, and as it harvests information and measurements it creates a 3D map of the rotating object, as well as noting the object’s direction, speed, and spin. The algorithm can also figure out center of mass, and could also be used for coordinating docking maneuvers or calculating the position of an asteroid so astronauts can land on it or move it.
Japanese space agency JAXA plans to make a go at cleaning up the cosmos with a huge magnetic net, and it will be interesting to see how that pans out. But that strategy could also be used in conjunction with this new tool, especially now that NASA has identified roughly 100 satellites that it wants to remove.