28 Sept 2012

Services disrupted as INSAT-3E loses crucial ‘Earth lock’



Indian Communication satellite Insat-3E successfully lifted off from Kaorou French Guyana in this September 28, 2003 picture.

Services on INSAT-3E, one of ISRO’s key communication satellites, were disrupted for most of Saturday, after the spacecraft lost its crucial Earth link.
“It is out of danger now, though services are yet to be restored,” a spokesman for the space agency told The Hindu in the evening.
Scientists at the Master Control Facility (MCF) in Hassan, 80 km from here, started working on restoring the “Earth lock” that was lost in the morning, he said. Until 8 p.m., there was some success. There were some glitches and the MCF scientists monitoring and commanding the satellite should correct them and restore the satellite fully by the end of the day, he said.
Some of BSNL’s services and many VSATs that support Internet communication use capacity on 3E. The disruption continued until 8 p.m. “Their operations weren’t shifted to a different satellite, as is usually done in such a situation,” he said.
Communications satellites, circling at around 36,000 km from the ground, face a particular point on Earth. INSAT-3E is turned Earthwards on top of the country and has a 24-hour orbit. It lost this link at 9.50 a.m. Weighing 2,750 kg, it is the country’s third-generation satellite. Built for a life of 15 years, it is now approaching its ninth year in orbit. It was launched on September 28, 2003, on a European vehicle, and placed at 55 degrees East longitude. It carries 24 transponders in the C-band, and 12 in the extended C-band, to support broadcasting and communication services of public and private sectors.
ISRO’s satellites often outlive their designed life.
GSAT-10, the country’s next communication satellite, will now fly on September 29 on a European vehicle.
Space agency ISRO has announced the new date on its website. The launch was deferred from September 21, after scientists at the Kourou Launch pad in South America noticed some dust in the rocket. That has apparently been corrected. The 3.4-tonne spacecraft carries 36 transponders — including 12 Ku, 12 C and 12 extended C-band. The capacity will support DTH (direct-to-home) and normal broadcasting and communication. It also has the second of the GPS Aided GEO Augmented Navigation (GAGAN) payload, which will fine-tune or ‘augment’ GPS readings used by pilots of civil airlines. (GAGAN is a project of the Airports Authority of India and ISRO.)

No comments: