The Hindu Business Line : IRS-1C completes 10 years in orbit

THEY built it to last just three years. But IRS-1C, the satellite that launched India into the rich niche of earth imagery sellers, has become arguably the longest serving remote sensing satellite, if not one of the world's very few long play ones. It has just completed 10 years in orbit and continues to surprise all by still going strong, according to its operator, ISRO.

1C, orbiting up there at 900 km, has generated revenues of over $10 million (around Rs 45 crore) from data sales within the country and internationally to a host of corporate and public sector users. It is till clicking away and ISRO says it will continue to use the data for as long as they come.

For some time after its launch, 1C, with its unique mix of three cameras, was a head-turner as it was the world's most advanced civilian remote sensing satellite. ISRO's first commercial success went on to give the agency a significant place in select segments of the imagery market over established leaders such as US and French satellites LANDSAT and SPOT.

"The success of IRS-1C paved the way for India to enter into the global remote sensing market and to capture a substantial share of the remote sensing data market. Its data provided a fillip to remote sensing applications in India like crop acreage and yield estimation, forest resources survey, urban mapping, flood mapping, wasteland mapping and drought monitoring and assessment," ISRO said.

The designated three-year lifespan itself is somewhat above the industry average for a remote sensing satellite. But 1C's decade-long performance has surprised even its sedate operator. If civilian satellites live barely for 2-3 years, defence satellites are said to be even more short-lived.

The extended life, according to the agency, is due to the meticulous handling of 1C in orbit in-orbit operations by the ISRO's Bangalore-based Telemetry, Tracking and Command Network (ISTRAC), coupled with efficient use of fuel on board, as well as the high reliability built into its subsystems.

Flown in December 28, 1995 by a Russian Molniya rocket from Baikonour, it has orbited the earth nearly 60,000 times and sent several lakh imageries. An identical satellite IRS-1D, which ISRO flew on its PSLV in September 1997, followed IRS-1C. Three thematic ones have come up since then: Oceansat-1, Resourcesat-1 and Cartosat-1, while Cartosat-2 is due to fly in a few months' time.