Michael Braukus
Headquarters, Washington, D.C.                                         
August 14, 1991
(Phone:  202/453-1549)

Jim Sahli 
Marshall Space Flight Center, Huntsville, Ala.
(Phone:  205/544-0034)


RELEASE:  91-130

NASA X-RAY TELESCOPE TO BE LAUNCHED ON JAPANESE SPACECRAFT

   NASA's Soft X-Ray Telescope, which will study solar flares, 
is scheduled to be launched aboard a Japanese spacecraft on 
Aug. 26, under a cooperative agreement with the Japanese.

   The telescope is one of four instruments on the Solar-A 
spacecraft to be launched into Earth orbit by the Institute of 
Space and Astronautical Science aboard a Japanese M-3S2 
three-stage, solid-fueled launch vehicle from the Kagoshima 
Space Center in Japan.

   "The purpose of the Solar-A mission is to study high energy 
phenomena in solar flares during the current solar maximum 
period.  The mission is expected to last 3 years," said John 
Owens, Project Manager for the NASA telescope.

   The Soft X-Ray Telescope is one of two major instruments to 
fly on the Solar-A satellite.  The Japanese Hard X-Ray 
Telescope is the other.  Other instruments are the Bragg 
Crystal Spectrometer from the United Kingdom and the Wide-Band 
Spectrometer from Japan.

   The Soft X-Ray Telescope has two principal investigators:  
Dr. Loren Acton of Lockheed Palo Alto Research Lab., Calif., 
and Dr. Tadashi Hirayama of the Tokyo Astronomical Observatory, 
Japan.

   The Marshall Space Flight Center, Huntsville, Ala.,  Payload 
Projects Office was responsible for managing the development of 
the instrument built by Lockheed Palo Alto Research Laboratory, 
Calif.  The instrument was integrated into the spacecraft in 
Japan by the Nippon Electric Co., the spacecraft's 
manufacturer.
                             -end-