This term covers both natural dust particles and human-made space junk that intersect spacecraft orbits. Because these objects travel at orbital velocities of several kilometers per second, even millimeter-sized flecks can punch through unarmored hulls, sever coolant lines, or degrade solar panels. Spacecraft designers use Whipple shields and specialized multi-layer insulation to protect critical components from these hypervelocity impacts.
Heard on the job
The inspection cameras found three new MMOD strikes on the radiator panels after the last spacewalk.