RHESSI is being funded by NASA's Explorers
Program (http://explorers.gsfc.nasa.gov/) under the category of
"Small Explorers." These are relatively low cost missions,
which have specific scientific objectives that are in line with a list of NASA
space science priorities.
Principal Investigator Robert Lin explains sun science and RHESSI mission
objectives. Featuring satellite data and images of the Sun.
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- Why is this mission happening, and why was it considered important enough for
NASA to fund it?
RHESSI may help to answer one of the most fundamental questions about how the sun
works: How do solar flares release such large quantities of energy in such
a short span of time? (A single flare can be as powerful as ten million
volcanic explosions!). For an excellent scientific overview and a complete
rationale for the mission, read the RHESSI Online
- Why must RHESSI make observations of the Sun from space? Can't the
same data be collected from Earth?
A very large part of the expense of the RHESSI mission is allocated to its
launch into space. This is necessary because
x-rays and gamma rays do not penetrate the Earth's atmosphere. RHESSI's observations
must be made from space. In fact, before the
advent of space-based observatories, there were only limited astronomical observations done
in the high energy portion of the electromagnetic spectrum. To understand why,
Transmission, or study this diagram
(scroll down to the bottom of the page).
- What is special about the RHESSI mission?
The centerpiece of the RHESSI mission is the imager, which uses a new
technology to capture images and spectra of high energy solar flares. The
imager uses a method which is quite unlike the cameras and telescopes that are
familiar to us; it has no lenses!
Learn more about the RHESSI