| Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI, originally High Energy Solar Spectroscopic Imager or HESSI or Explorer 81) was a NASA solar flare observatory. It was the sixth mission in the Small Explorer program (SMEX), selected in October 1997 and launched on 5 February 2002, at 20:58:12 UTC. Its primary mission was to explore the physics of particle acceleration and energy release in solar flares.
The spacecraft re-entered Earth's atmosphere at 00:21 UTC on 20 April 2023, 21 years after its launch. |
