Launched in July 1992, Geotail was designed to study Earth’s magnetosphere as particles are affected by our planet’s magnetic field.
It is important for our well-being as it protects us from dangerous space radiation. Because this radiation comes mainly as solar winds from the sun, the magnetosphere is not a round bubble – instead, it has the shape of a long tail on the night side of the planet due to an influx of particles from the sun.
The geographic tail revolved around the Earth in a highly elliptical orbit, which allowed her to study this tail and learn about its structure and dynamics. Instruments were used to monitor magnetic and electric fields, as well as plasma and high-energy particles.
Originally designed to only last four years, the satellite has lasted 30 years of operation, providing data for more than a thousand scientific papers, Digitartlends reported.
The mission was also noteworthy because it was a partnership between NASA and the Japanese space agency JAXA.
“Geotail has been a very productive satellite, the first joint NASA-JAXA mission,” Don Fairfield, NASA’s first project scientist for Geotail, said in a statement. “The mission made important contributions to our understanding of how the solar wind interacts with Earth’s magnetic field to produce magnetic storms and aurora borealis.”
Geotail didn’t have an easy time during her entire mission. In 1993, a year after its launch, one of its computers failed, and it looked as if one of the mission’s main instruments, the Low Energy Particle Experiment, would be unusable.
The team tried resetting the computer with no luck, so they chose a nail-biting option to adjust the satellite’s orbit by sending it around the dark side of the moon, where it would be temporarily blocked from sunlight and without power.
After 10 minutes in the dark, the satellite returned to sunlight and the computer restarted successfully.
This allowed the mission to proceed as planned, but after decades of use, components began to fail.
In 2012, one of the data loggers went out of business. The second recorder worked until June 2022, when it suffered a problem and could not be revived.
Mission operations ended in November 2022, and NASA recently announced that the mission has officially ended.
The geographic tail leaves a legacy of discoveries about the magnetosphere, as well as traces of material in the Moon’s extremely thin atmosphere.
Its work continues with newer missions such as the Magnetospheric Multiscale mission launched in 2015.