Geotail
Geotail — a Japanese–American satellite (ISAS/JAXA and NASA) that studied the magnetotail, the long tail of Earth's magnetic field drawn out by the solar wind, from 1992 to 2022. For its first two years lunar swingbys kept its orbit reaching up to about 200 Earth radii down the tail; from early 1995 it flew a nearer orbit, between about 9 and 30 Earth radii. (Its orbit is drawn to its published size; its orientation and position on it are representative.)
Key facts
Mission & specifications
Mission
- Operator
- ISAS/JAXA (Japan) / NASA
- Launched
- July 24, 1992
- Status
- Completed
Trajectory
- Distance from the Sun
- 0.996 AU
- Computed from the cached position
- Distance from Earth
- 1,461,182 km
- Computed from cached positions
- Distance from Venus
- 0.276 AU
- Computed from cached positions
Mission
Geotail was a joint mission of Japan's Institute of Space and Astronautical Science (now part of JAXA) and NASA, launched on a Delta II from Cape Canaveral on 24 July 1992. It belonged to the International Solar-Terrestrial Physics programme with Wind, Polar, SOHO and Cluster, and its target was the magnetotail — the long tail into which the solar wind draws Earth's magnetic field on the night side, where energy is stored and suddenly released to drive auroras. For its first two years a series of double lunar swingbys kept the far point of its orbit on Earth's night side, deep in the distant tail, up to about 200 Earth radii away. From November 1994 manoeuvres brought it closer, and from early 1995 it flew an orbit between about 9 and 30 Earth radii to study the near tail. Built for about four years, it worked for thirty. One of its two data recorders failed in 2012 and the other had an anomaly on 28 June 2022; with too little data coming back, operations ended on 28 November 2022.
- 1992Geotail launches on a Delta II rocketLaunch
A joint mission of Japan's ISAS and NASA.
- 2022Data recorder anomalyMilestone
Its second recorder falters; the first had failed in 2012.
- 2022Operations endMission end
After thirty years on a mission built for four.
Images
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