IRS 1A, 1B

IRS 1A [ISRO]

IRS 1A and 1B (Indian Remote Sensing Satellite) were the first of the series of indigenous state-of-art remote sensing satellites.

IRS-1A, was successfully launched into a polar sun-synchronous orbit on 17 March 1988 from the Soviet Cosmodrome at Baikonur on a Vostok-2M booster. IRS-1A carried two cameras, LISS-I and LISS-II with resolutions of 73 meters and 36.25 meters respectively with a swath width of about 140 km during each pass over the country. Its mission was completed during July 1996 after serving for 8 years and 4 months.

IRS-1B was launched on 29 August 1991 also on a Vostok-2M booster. It had some improved features compared to its predecessor: gyro referencing for better orientation sensing, time tagged commanding facility for more flexilibility in camera operation and line count information for better data product generation. The missiion of IRS-1B ended on 20 December 2003 after serving for 12 years and 4 months.

An engineering model was later modified into the IRS 1E satellite.