ISEE-3: first halo orbit at a Lagrange point and first comet visited
ISEE-3: primera órbita halo en un punto de Lagrange y primer cometa visitado
- Date
- 1978 · confidence high
- Place
- Goddard Space Flight Center, Greenbelt, Maryland, United States
- Credited to
- NASA and ESA (Robert Farquhar, trajectory)
- Field
- Movement
What was discovered
Launched in 1978, ISEE-3 was the first craft in a halo orbit around the Sun-Earth L1 Lagrange point, where it monitored the solar wind. In 1985, repurposed as ICE, it flew through the tail of comet Giacobini-Zinner, the first comet visited.
The craft returned close to Earth in 2014; a citizen team made contact with it but could not reactivate its thrusters.
What it led to
- halo orbits for SOHO, Wind, Gaia and the James Webb Space Telescope
- space-weather monitoring from L1
- the first visit to a comet, ahead of the Halley probes (1986)