Reuven Ramaty High Energy Solar Spectroscopic Imager significant event rocket launch
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.
Spacecraft re-entered Earth's atmosphere at 8:21 p.m. EDT on April 19, 21 years after its launch.