Insat-3D gave scientists anxious moments after launch

Minutes following the launch of INSAT-3D satellite last month to help forecast weather and predict natural disasters, scientists at the Indian Space and Research Organization (ISRO) went through some moments of extreme anxiety.

The satellite, weighing nearly 2000 kilos and costing Rs200 crore, exhibited "anomalous behaviour", spinning at a much higher rate followed by a total communication break down between the satellite and the Master Control Facility at Hasan in Karnataka which "was lost for a short duration," said ISRO chairman K Radhakrishnan.

A communication blackout with the satellite, which was launched using a French rocket in French Guiana, could have resulted in the satellite spinning out of control.

According to ISRO, it used "contingency measures" to move the satellite back onto its planned orbit.

Relieved scientists today told NDTV that the satellite was "healthy and has reached its final resting place above Earth" and would be most likely be functional in a week.

The bird in the sky would help in issuing early warnings about storms and cloud bursts. On board, the India- made satellite is special equipment that would measure atmospheric humidity and temperature to help forecast heavy rainfall events.

According to experts, it could have helped to forecast the catastrophic rainfall that ravaged Uttarakhand in July, that left thousands of people dead and thousands others missing.

Meanwhile, according to an ISRO statement issued yesterday, the satellite had now been successfully placed in a geosynchronous orbit. The satellite would eventually be placed in a geostationary orbit from where it could monitor weather conditions over the same region continuously.

According to the statement, Insat-3D was now moving towards its final geostationary orbital location of 82 degree East longitude and on August 6, 2013 it would reach this destination.

"Subsequently, the two meteorological payloads (Imaging System, Atmospheric Sounder), as well as the two Transponders (designed for the Meteorological Data Relay and Satellite-aided Search and Rescue system) will be activated by August 8, 2013," it said.

Before reaching the 36,000 km orbit, the satellite was now on a slightly elliptical path with an apogee (farthest point to earth) of 35,799 km and a perigee (nearest point to Earth) of 35,469 km.