RHESSI is a NASA Small Explorer (SMEX) mission to image and make high resolution spectroscopic observations of solar flares in the energy range of 3 keV (X-rays) to 20 MeV (gamma rays). Energy resolution ranges from 0.5 to 5 keV with angular resolution from 7 to 30 arcseconds. RHESSI's primary mission objectives are to: 1) determine the frequency, location, and evolution of impulsive energy release in the corona; 2) study the acceleration of electrons, protons, and heavier ions in flares; 3) study the heating of plasma and determine its relationship to particle acceleration; 4) study the propagation and evolution of energetic particles in flares; and 5) determine the relative abundances of accelerated and ambient ions in flares.
RHESSI's non-Solar objectives are to: 1) obtain high resolution images and spectra of the Crab Nebula; 2) detect and obtain high resolution spectra of gamma-ray bursts and cosmic and terrestrial transient sources over a large fraction of the sky; 3) search for cyclotron line features in gamma-ray bursts and cosmic transient sources; and 4) obtain high resolution spectra and search for line features in steady X-ray and gamma-ray sources.
Orbit/Altitude & Inclination: 600 km, circular @ 30°
Launch Mass: 291 kg
Solar Arrays: 505 W EOL, four deployable wings
Stabilization: Spin stabilized @ 15 RPM, solar pointed
Design Life: 3 years
Operational, launched February 5, 2002
Customer: University of California,
Space Sciences Lab, Berkeley, CA
Mission: NASA Small Explorer (SMEX) Program
Quick Facts RHESSI successfully completed its two-year mission in March 2004 and continues to collect on-orbit data after more than ten years
The onboard instrument observes and collects X-ray and gamma ray emissions with an unprecedented combination of high-resolution imaging and spectroscopy
Simple, easily integrated design based on Orbital's flight-proven LEOStar-2 spacecraft architecture