Objects in space tend to spin - and spin in a way very different from the way they spin on earth. Understanding how objects are spinning, where their centers of mass are, and how their mass is distributed is crucial to any space mission - from cleaning up debris to landing a demolition crew on a comet. MIT researchers have now tested an algorithm for gauging the rotation of objects in zero gravity using only visual information, aboard the International Space Station (ISS). This video shows three tests where a tracked object is spinning on its major, minor, and intermediate axes. The researchers tested their algorithm using two small satellites deployed to the ISS through MIT’s SPHERES project, which envisions that groups of coordinated satellites the size of volleyballs will assist human crews on future space missions. Their algorithm was mostly accurate, even when it ran in real time on the microprocessor of a single experimental satellite.