HXRS

The Hard X-Ray Spectrometer was developed by Space Devices for a joint space experiment of scientists at the NOAA Space Enviroment Centre (SEC) in Boulder, CO in collaboration with the Astronomical Institute of Czech Academy of Sciences. The experiment was conceived in 1990-1991 to use a Czech hard x-ray spectrometer, similar to that developed for the Russian CORONAS mission, is placed aboard an American satelite with the primary objective of predicating proton storms in the vicinity of Earth that are potentially harmful to satelites and humans in space. The head of czech team of scientists intended in HXRX project is Dr. Farnik from Solar Physics dpt. of Astronomical Institute.

SEC provides a wide variety of tasks under it's mandate to perform space weather forecasts, particularly with respect to the issuance of alerts and warnings. Two of it's most outstanding responsibilities concern the forecast of geomagnetic storms, resulting primarily from large ejecta from the Sun, and the forecast of proton storms, resulting primarily from combination of flare activity and interplanetary shocks. The ability to forecast this phenomana with great accuracy would represent a major advancement in the Center's primary mission.

The HXRS experiment was manifested for space flight in May 1997 by the Department of Defense Space Test Program and selected for the space flight by the DoD Space Experiment Review Board from among a field of 30 candidate experiments, where the critaria was accuracy, reliability and military relevance. The HXRS will fly piggyback on the host satelite, Multispectral Thermal Imager (MTI) built and subsequently to be operated by the Sandia National Laboratories in Albuquerque, NM for the Department of Energy.The mission will be launched from Vandenburg AFB in October, 1999. The expected lifetime is three years which encomapss the peak of solar cycle 23, now in progress.
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HXRS ready for integration aboard MTI


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Scintillation detector
with shielding
and calibration mechanics

The HXRS was designed primarily as an experiment, not as an operational device. This approach was adopted in part because of the need to investigate the influence of electron background on this type of measurement. To investigat this influence the HXRS has been equipped with two identical side-by-side detectors, one shielded and one unshielded. The shildeing consists of organic plastic absorbers for moderating bremsstrahling on the sides of the detector and a strong permanent magnet to deflect boresighted particles away from the entrance apperture. This construction will thus permit a quantitative assessment of the shileding efficency in a hot particle enviroment.

The MTI satelite will be launched into 555km circular orbit inclined at 97 degrees to earth's equator. The spacecraft sollar arrays (and HXRS, of course) are in normal operation Sun directed with ~1 degree pointing accuracy. Data downlinks will be made to the Sandria receiving station in central New Mexico on twice daily basis.

The flight hardware was delivered to the Ball Aerospace Systems Division on January 6. The instrument is currently being integrated to the MTI spacecraft and will undergo envirimental tests in anticipation of the launch to orbit in October 1999. Enlarge MCH

Analogue measurement
channel's board