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.

[NOTE: Images supporting this release are available at]