The HESSI (
High Energy Solar Spectroscopic Imager)
satellite, is due to be launched in March this year on a 2 year mission to "explore the
basic physics of
particle acceleration and
energy release in
solar flares".
The orbital vehicle itself is quite small, weighing in at 290kg (mainly as the unit is only carrying one instrument). HESSI will sit in a single spin-stabilized low-altitude orbit 600km above the equator, armed with an imaging spectrometer, obtaining high fidelity colour movies of solar flares and the associated X-rays and gamma rays
NASA hopes that HESSI will help them determine how much energy is released in a flare and how the vast numbers of electrons and protons contained in a flare are accelerated to such high speeds in the time the flare lasts.
Information taken from:
http://hesperia.gsfc.nasa.gov/hessi/
http://hessi.ssl.berkeley.edu/