"RHESSI is a great example of how a relatively low-cost satellite can achieve world-class science," said W. David Thompson, Spectrum Astro President and CEO. "We are very proud to have been involved with this very successful team."

In August 2003, RHESSI received the NASA Senior Review Panel's highest rating of any of the 14 Sun-Earth Connection (SEC) missions. The panel rated the RHESSI program as "clearly superior" with "compelling science and relevance to the SEC mission."

RHESSI's primary mission is to explore the basic physics of particle acceleration and the explosive energy release in solar flares. RHESSI has obtained many "first time" observations of solar processes. Some of its important results include the first imaging of a flare in gamma-rays, the discovery of strong polarization in a cosmic gamma-ray burst; the first detection of continuous glow from the sun at 3-15 KeV energies; and the first hard X-ray imaging spectroscopy of flares from thermal to non-thermal energies.

RHESSI is the sixth Small Explorer (SMEX) mission and the first to be managed in the "principal investigator" mode. Professor Robert P. Lin of the University of California, Berkeley is the principal investigator for RHESSI, responsible for instrument and spacecraft development, mission operations, and data analysis. The Explorer Program Office at NASA's Goddard Space Flight Center in Greenbelt, MD provides program management and technical oversight for the mission for NASA's Office of Space Science in Washington.

Total mission cost for RHESSI is about $85 million, which includes the spacecraft, science payload, launch vehicle, mission operations, and data analysis.

The RHESSI scientific payload is a collaborative effort among the University of California, Berkeley; Goddard; the Paul Scherrer Institute in Switzerland; and the Lawrence Berkeley National Laboratory in Berkeley. The mission also involves additional scientific participation from France, Japan, The Netherlands, Scotland, and Switzerland.