HESSI
High Energy Solar Spectroscopic Imager, also called SMEX 6, later
renamed RHESSI (Reuven Ramaty High-Energy Solar Spectroscopic Imager)
HESSI will investigate the physics of particle acceleration and energy release
in solar flares through an unprecedented combination of high resolution imaging
and spectroscopy of X-rays and gamma rays from 2 keV to 20 MeV during the next
solar maximum.
Project cost: $85 million (including $13 million for launch)
In Mar 2000, the satellite was damaged when during a test it was shaken 10
times harder than intended. Once on orbit, the satellite proved to work
properly.
http://hesperia.gsfc.nasa.gov/hessi/
http://hessi.ssl.berkeley.edu/
sat-index articles
Prime
contractor
|
Spectrum
Astro Inc
|
Platform
|
derived
from SA-200S
|
Mass
at launch
|
304
kg
|
Mass
in orbit
|
|
Dimension
|
|
Solar
array
|
4
panels
|
Stabilization
|
spin
stabilized (15 rpm)
|
DC
power
|
120
W
|
Design
lifetime
|
2
years
|
It uses Fourier-transform imaging with 12 bi-grid modulation collimators and
cooled germanium and silicon detectors mounted on a Sun-pointed spin-stabilized
spacecraft in a low-altitude equatorial orbit. HESSI will carry out the first
imaging spectroscopy in hard X-rays with 2 arcseconds angular resolution, time
resolution to tens of ms, and \sim1 keV energy resolution; the first gamma-ray
line spectroscopy from a spacecraft with \sim1 keV energy resolution; and the
first gamma-ray line and continuum imaging with 20 arcseconds angular
resolution.