OTD in Space - September 11: International Cometary Explorer Completes 1st Comet Flyby

On Sept. 11, 1985, the International Cometary Explorer, or "ICE" became the first spacecraft to fly by a comet.

Originally launched as the International Sun-Earth Explorer-3 in 1978, ICE was one of three spacecraft built for the International Sun-Earth Explorer (ISEE) program, a joint effort by NASA, the European Space Research Organization and the European Space Agency.
The program's purpose was to study space weather, or the interaction between the Earth's magnetic field and the solar wind.
After completing its original mission, the spacecraft did a maneuver to steer it toward comet Giacobini-Zinner. It flew straight through the comet's plasma tail, but it didn't stop there! Six months later, it flew by Halley's comet, too.