Garbage scow

Star Trek: The Next Generation
Episode: TNG 183 - Final Mission

An unmanned, sublight freighter of unknown origin, this garbage scow pulled into the orbit of Gamelan V and its toxic cargo leaked. The ensuing radiation caused atmospheric radioactivity levels to increase by 3,000%.

Commander Riker and Enterprise came to Gamelan V's aid, towing the scow safely away from the planet.