 RHESSI spacecraft observing the Sun | |
| Names | Explorer 81 HESSI High Energy Solar Spectroscopic Imager RHESSI SMEX-6 |
|---|---|
| Mission type | Solar observatory |
| Operator | NASA / Space Sciences Laboratory |
| COSPAR ID | 2002-004A |
| SATCAT no. | 27370 |
| Website | RHESSI |
| Mission duration | 2 years (planned) [1] 16 years, 6 months, 10 days (achieved) |
| Spacecraft properties | |
| Spacecraft | Explorer LXXXI |
| Spacecraft type | Reuven Ramaty High Energy Solar Spectroscopic Imager |
| Bus | RHESSI |
| Manufacturer | Spectrum Astro Inc.[1] |
| Launch mass | 293 kg (646 lb) [2] |
| Dimensions | 2.16 × 5.76 m (7 ft 1 in × 18 ft 11 in) |
| Power | 414 watts |
| Start of mission | |
| Launch date | 5 February 2002, 20:58:12 UTC[3] |
| Rocket | Pegasus XL (F31) |
| Launch site | Cape Canaveral, Stargazer |
| Contractor | Orbital Sciences Corporation |
| Entered service | 2002 |
| End of mission | |
| Deactivated | 16 August 2018 [4] |
| Last contact | 11 April 2018 |
| Decay date | 20 April 2023 (UTC)[5] |
| Orbital parameters | |
| Reference system | Geocentric orbit[6] |
| Regime | Low Earth orbit |
| Perigee altitude | 579 km (360 mi) |
| Apogee altitude | 607 km (377 mi) |
| Inclination | 38.04° |
| Period | 96.50 minutes |
| Main telescope | |
| Type | Coded aperture mask |
| Focal length | 1.55 m (5 ft 1 in) |
| Collecting area | 150 cm2 (23 sq in) |
| Wavelengths | X-ray / gamma ray (γ-ray) |
| Resolution | 2 arcseconds up to 100 keV 7 arcseconds up to 400 keV 36 arcseconds above 1 MeV [2] |
| Instruments | |
| Reuven Ramaty High-Energy Solar Spectroscopic Imager (RHESSI) | |
 HESSI mission patch Explorer program | |
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 [1][7] 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.[5]
- ^ a b c "RHESSI (Reuven Ramaty High Energy Solar Spectroscopic Imager)". eoPortal Directory. European Space Agency (ESA). Retrieved 16 March 2021.
- ^ a b "RHESSI Mission Facts". NASA. Retrieved 3 September 2015.
This article incorporates text from this source, which is in the public domain.
- ^ "Launch Log". Jonathan's Space Report. 28 November 2021. Retrieved 3 December 2021.
- ^ Cite error: The named reference
nasa20181120was invoked but never defined (see the help page). - ^ a b "NASA Retired Solar Energy Imager Spacecraft Reenters Atmosphere". 24 April 2023. Archived from the original on 24 April 2023.
- ^ "Trajectory: RHESSI (Explorer 81) 2002-004A". 28 October 2021. Retrieved 3 December 2021. This article incorporates text from this source, which is in the public domain.
- ^ Dennis, Brian (30 April 2009). "RHESSI - Concept to Fruition". Space Sciences Laboratory. Retrieved 15 January 2015.
