INSAT 2D is abandoned

BANGALORE, Oct 5: INSAT 2D, the fourth and penultimate satellite in the indigenously-built second generation INSAT series has been abandone...

BANGALORE, Oct 5: INSAT 2D, the fourth and penultimate satellite in the indigenously-built second generation INSAT series has been abandoned. The satellite, which was restored after it lost earth lock on October 1 due to a short circuit in one of the two power supply lines, again lost earth lock on October 4.

Scientists have determined that further recovery is not possible.Earth lock refers to the need to keep the earth-viewing face of the satellite steadily pointed towards the earth, without any wobbling in the antennae.

The 2,070-kg Rs 120-crore satellite had been re-acquired on October 2, but was generating only about 25 to 30 per cent of the rated power output. The 23 transponders had been switched off, and later, three C band transponders had been turned back on.

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However, according to the Indian Space Research Organisation (ISRO), the spacecraft had lost all redundancy, and its thermal management had become difficult. Then problems arose in the propulsion system that is used to maintain the altitude of the satellite, in its geo-stationary position at 74 degree East longitude, 36,000 kilometres above the earth. The compounding of the problems has made recovery impossible, and it has now been abandoned, ISRO sources said. Only seven of the 23 transponders had been put to use, and some of the services had been transferred to other INSAT satellites.

Three were being used by the National Stock Exchange (NSE), while the other four were being used by the Department of Telecommunications (DoT).

Telecom links were cut off from about 83 stations, in several district headquarters in the North, especially in the remote areas of the North-East, Jammu and Kashmir, the hilly regions of Uttar Pradesh, and tribal regions in Madhya Pradesh.