In the present day within the historical past of astronomy, a spacecraft does a comet flyby for the primary time.

Initially the ISEE-3 mission, the ICE probe (seen right here in an artist’s idea) was renamed when it was repurposed to intercept a comet. Credit score: NASA
- The Worldwide Solar-Earth Explorer-3 (ISEE-3) mission, a joint NASA-ESA endeavor launched in 1978, initially studied the photo voltaic wind and Earth’s magnetic area from the L1 Lagrange level.
- Following its main mission, ISEE-3 (renamed Worldwide Cometary Explorer or ICE) was repurposed to intercept Comet 21P/Giacobini-Zinner, attaining the first-ever cometary encounter by a spacecraft in September 1985.
- Knowledge collected throughout the ICE mission offered proof supporting the “soiled snowball” principle concerning cometary composition.
- Subsequent to the Giacobini-Zinner encounter, ICE was additional utilized to check Comet Halley in 1986; communication with the probe ceased in 1997, however was later re-established in 2014 by an impartial staff.
Launched because the Worldwide Solar-Earth Explorer-3 in 1978, a joint NASA-ESA mission, the ISEE-3 probe studied the photo voltaic wind and Earth’s magnetic area from the L1 Lagrange level. When its mission was full in 1981, NASA proposed repurposing the craft by utilizing it to intercept a comet; such reuse would save the time and cash of constructing a brand new spacecraft. Renamed the Worldwide Cometary Explorer, ICE was redirected by way of a sequence of lunar flybys, setting it as much as intercept Comet 21P/Giacobini-Zinner. On Sept. 11, 1985, the probe handed by way of the tail of the comet, roughly 4,885 miles (7860 kilometers) from its nucleus. The spacecraft returned knowledge on the make-up of the comet’s tail, supporting the speculation that they’re “soiled snowballs.” It was the first-ever encounter of a human-made spacecraft with a comet. NASA continued to reuse ICE afterwards, flying it by way of the tail of Comet Halley in 1986. Although the company ceased contact with the probe in 1997, an impartial staff of researchers referred to as the ISEE-3 Reboot Mission efficiently reestablished communication with the craft in 2014, firing its thrusters for the primary time in 27 years.