The Collisions Into Dust Experiment (COLLIDE) was an experiment designed specifically for microgravity environments to investigate dust production in planetary rings by simulating planetary ring particle collisions at low-velocities. It was originally designed as a Get Away Special (GAS) payload to fly on space shuttle Columbia and successfully flew in April 1998 on STS-90.
COLLIDE’s experiments studied collisions between particles in microgravity to better understand how planets and rings formed. During each COLLIDE experiment, a marble sized sphere was launched into a very fine powder and very low speeds. The impacts were video recorded for post-experiment evaluation.
When collisions are slower than 20 cm/s, the impacting particle sticks to the powder surface. Particles moving at these speeds can easily lead to planetary growth.