The Indian Remote Sensing satellite, IRS-1B, which was launched on board the Russian Vostok launcher on August 29, 1991, has successfully completed 10 years of operation. The 990 kg satellite carries two cameras - Linear Imaging Self Scanner (LISS-1) with a spatial resolution of 72.5 m and a ground swath of 148 km and LISS-IIA and LISS-IIB with a spatial resolution of 36.25 m and a composite ground swath of 146 km. The satellite is placed in a polar sun-synchronous orbit at a height of 904 km with an orbital period of 103 minutes. The satellite can image the entire earth once in 22 days.

It is significant that IRS-1B has far outlived its design life of three years. The performance of the satellite has been quite excellent, in that there has been no degradation of image quality taken at the beginning of the satellite mission and the imagery obtained even now. The data from this satellite has not only been received and used in India, but also by the USA. In all, the cameras on board IRS-1B have been operated for more than 7000 times over India in the last 10 years and for more than 4100 times over the USA between April 1994 and February 1999.

IRS-1B gave a valuable experience for designing and launching its follow-on satellites IRS-1C and IRS-1D, considered as the world's best in terms of spatial and spectral resolution.

Even after 10 years of operation, IRS-1B, will continue to be used for conducting various experiments including studying the design margins of the various subsystems and to test different modes of operation using the available fuel.