New Delhi: INSAT-1A was an Indian communications satellite launched on April 10, 1982 as part of the Indian National Satellite System or INSAT-1 program. This year, April 10 marks the 40th anniversary of the satellite’s launch.
The INSAT-1 program comprised two three-axis stabilized spacecraft in geostationary orbit, namely INSAT-1A and INSAT-1B, with a host of ground stations across India, according to NASA.
Here are ten facts you need to know about INSAT-1A.
- The INSAT-1A satellite was built by the Ford Aerospace and Communications Corporation and was designed to provide combined telecommunications, direct-to-home television and meteorological services to the Indian civilian community.
- INSAT-1A was launched on April 10, 1982, using a Delta 3910 rocket with a PAM-D upper stage, from Launch Complex 17A at Cape Canaveral Air Force Station, United States. PAM or Payload Assist Module is a portable launch platform to help launch small satellites with Space Shuttle, Delta and Titan launch vehicles, and transport satellites from low Earth orbit to geostationary transfer orbit.
- The satellite had a mass of 1152.1 kilograms.
- INSAT-1A’s telecommunications package provided two-way long distance telephone circuits and direct radio and television broadcast to the remotest parts of India. It had 12 transponders operating at certain frequencies for communication in remote areas and distribution of television programs. It had two transponders for direct broadcast to augmented low-cost community television sets in rural areas, radio program distribution, national television network, and disaster warning.
- The INSAT-1A data collection and transmission package consisted of a data channel allowing the relay of meteorological, hydrological and oceanographic data from unattended land and ocean data collection and transmission platforms.
- The meteorological ensemble consisted of a two-channel, very high resolution scanning radiometer (VHRR) to provide full coverage of the Earth every 30 minutes. The visible channel had a resolution of 2.75 kilometers and the infrared channel had a resolution of 11 kilometers.
- These observations were used to monitor land and sea weather systems. For example, cyclones could be observed, and sea surface and cloud top temperatures could be measured.
- Early warnings of impending disasters such as floods and storms could directly reach the civilian population, even in remote areas, through the INSAT television capability.
- INSAT-1A had some initial difficulties deploying its antennas and solar array after launch. For 12 days, the C-band antenna could not be deployed, and the solar panel could not fully extend. This prevented INSAT-1A from generating enough power to perform weather observations.
- Subsequently, the satellite’s transponders overheated and failed. The satellite’s primary Earth-tracking sensor was disabled on September 4, 1982 to protect the system while the Sun passed through its field of view. According to the Indian Space Research Organization (ISRO), INSAT-1A was abandoned in September 1983 when its altitude control thruster was exhausted.