| Name of Satellite, Alternate Names | HESSI (RHESSI, Reuven Ramaty High Energy Solar Spectroscopic Imager) |
| Country of Operator/Owner | USA |
| Operator/Owner | Space Sciences Laboratory, UC Berkeley/NASA |
| Users | Government/Civil |
| Purpose | Astrophysics |
| Class of Orbit | LEO |
| Type of Orbit | Intermediate |
| Longitude of GEO (degrees) | 0 |
| Perigee (km) | 535 |
| Apogee (km) | 551 |
| Eccentricity | 0.0011572399826414 |
| Inclination (degrees) | 38 |
| Period (minutes) | 95.5 |
| Launch Mass (kg.) | 293 |
| Dry Mass (kg.) | |
| Power (watts) | 414 |
| Date of Launch | 05-02-2002 |
| Expected Lifetime | 3 yrs. |
| Contractor | Spectrum Astro, Inc. |
| Country of Contractor | USA |
| Launch Site | Cape Canaveral |
| Launch Vehicle | Pegasus |
| COSPAR Number | 2002-004A |
| NORAD Number | 27370 |
| Comments | Explore basic physics of particle acceleration and explosive energy release in solar flares. |