Preliminary results of scientific investigations aboard the first Indian satellite.

The first Indian satellite, Ariabata, was launched into a nearly circular 600-km orbit from a Soviet launch base on Apr. 19, 1975. The purpose of the satellite, which carries solar cells for power needs, bears omnidirectional antennas, and is single-axis-spin-stabilized by means of dry compressed air, is to prepare the way for the production of other more complex Indian satellites for earth-resources monitoring and communication. The satellite bears several detectors for the monitoring of radiation: (1) a scintillation counter for detecting X-rays from galactic sources in the range 10 to 100 keV; (2) a detector for solar neutrons and gamma rays; (3) a detector of low-energy electrons in the ionosphere, and (4) two UV detectors. Initial results of the X-ray and neutron-gamma experiments are presented.