Fun with solar energy...

[Susan Gawarecki <loc@ICX.NET>]

Fun with solar energy...



NASA Press Release - HESSI SPACECRAFT TO STEAL EXPLOSIVE SOLAR SECRETS

WITH X-RAY VISION



     A new NASA spacecraft will soon be studying gigantic 

explosions in the atmosphere of the Sun with a unique kind of 

X-ray vision, producing the first high-fidelity color movies 

of solar flares in their highest energy emissions.

 

"The Sun has a trick that nobody totally understands," said 

Dr. Richard Fisher, Chief of the Laboratory for Astronomy and 

Solar Physics at NASA's Goddard Space Flight Center, 

Greenbelt, MD. "It can take magnetic energy and turn it into 

a stunningly powerful blast of heat, light and radiation. 

NASA's High Energy Solar Spectroscopic Imager (HESSI) will 

finally unlock the secrets of the initiation and onset of 

flares."

 

HESSI is scheduled to take off June 7 at 9 a.m. EDT from Cape 

Canaveral Air Force Station, FL aboard a Stargazer L-1011 

aircraft. The Stargazer cradles HESSI under its belly, stored 

inside A Pegasus rocket. At 10:05 a.m. EDT, the aircraft 

should release the Pegasus and deliver the spacecraft to its 

circular orbit 373 miles above the Earth, inclined at 38 

degrees to the equator.



Within the gigantic flare explosions, magnetic fields twist, 

snap and recombine, blasting particles to almost the speed of 

light, firing solar gas to tens of millions of degrees. This 

action causes the solar atmosphere to sizzle with high-energy 

X-rays and gamma rays  and accelerate proton and electron 

particles into the solar system. Radiation and particles from 

solar flares sometimes affect orbiting spacecraft, 

interfering with communications and astronaut activities.



In order to understand what triggers a solar flare and how it 

explosively releases energy, scientists must identify the 

different kinds of particles being accelerated, locate the 

regions where the acceleration occurs and determine when the 

particles get accelerated. The most direct tracer of these 

accelerated particles is the X-ray and gamma ray radiation 

that they produce as they travel through the solar 

atmosphere.  



To understand the physical processes and conditions inside 

flares, HESSI will create images in gamma rays and the 

highest energy X-rays emitted by the flare. These images will 

be the first to simultaneously measure the location and 

energy content of radiation from the flare material. This 

kind of data is expected to improve predictability of flare 

occurrence at the Sun and the subsequent consequences we 

experience here on Earth. Using the Sun as a laboratory, 

where such high-energy events take place, will provide 

scientists insight into interpreting similar high-energy 

activity that originate elsewhere in the universe.



Because HESSI has the finest angular and spectral resolution 

of any hard X-ray or gamma ray instrument ever flown in 

space, it will enable researchers for the first time to look 

at the development of high-energy reactions in flares. 

Powerful X-rays and gamma rays penetrate all materials, to 

some extent, and cannot be easily focused, so researchers are 

using another technique to form images. HESSI's sole 

instrument - an imaging spectrometer - will construct a flare 

image from patterns of light and shadows produced by high-

energy radiation that passes through the telescope's grids 

while the spacecraft rotates. Using this new method, HESSI is 

expected to gather data on thousands of flares during its 

two-to-three-year mission.  



Working together with other solar spacecraft - Yohkoh, the 

Solar and Heliospheric Observatory (SOHO), Geostationary 

Operational Environmental Satellites (GOES) and the 

Transitional Regional and Coronal Explorer (TRACE) for flare 

radiation, and Wind, the Advanced Composition Explorer (ACE), 

Ulysses, and Voyager for particle detection ­ HESSI will 

provide vital insight into the impulsive energy release and 

particle acceleration processes at the Sun.   



The HESSI mission costs about $85 million, which includes the 

spacecraft, launch vehicle, mission operations and data 

analysis. NASA's Office of Space Science, Headquarters, 

Washington, DC, provided funding for HESSI, and the Explorers 

Program Office at Goddard provides management and technical 

oversight for the mission.  



For more information on the Internet about the spacecraft and 

science mission, go to: 

           http://hesperia.gsfc.nasa.gov/hessi

              http://hessi.ssl.berkeley.edu/

-- 

.....................................................

Susan L. Gawarecki, Ph.D., Executive Director

Oak Ridge Reservation Local Oversight Committee

                       -----                       

A schedule of meetings on DOE issues is posted on our Web site

http://www.local-oversight.org/meetings.html - E-mail loc@icx.net

.....................................................





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