BENGALURU: Alarms at the Isro Telemetry, Tracking and Command Network’s (Istrac) mission control centre for satellite-aided SAR (search and rescue) in Bengaluru began going off at 12.20pm on Tuesday. The distress signal was from a beacon on the Pawan Hans helicopter, forced to make an emergency landing in sea more than 100 km off the coast of Mumbai.
In six minutes — exactly at 12.26pm — an Indian satellite traced the chopper and sent back information with specific details of its location to the control, which was then transmitted to rescue teams, which acted swiftly to rescue all nine passengers. But four of them died later.
The six-minute operation by Isro on Tuesday is not a stray incident. Satellite-based search and rescue services provided by the space agency have helped save more than 2,350 lives involved in 164 incidents since 1991, while 231 lives have been lost despite the efforts.
These include incidents involving seven nearby countries — Nepal, Bhutan, Sri Lanka, Bangladesh, Maldives, Seychelles and Tanzania — that Isro helps.
India is a member of the international Cospas-Sarsat programme (a global satellite-aided search and rescue initiative) for providing distress alert and position location services through low earth orbit search and rescue (LEOSAR) and geostationary orbit SAR (GEOSAR) satellite systems.
“Isro joined the Cospas-Sarsat in the 1990s and began providing services to maritime and aviation users and persons in distress situations. Access is provided to all states on a non-discriminatory basis, and is free of charge for the end-users. Since inception, Isro’s Indian Mission Control Centre (INMCC) has contributed to saving more than 2,300 lives across the Indian mission control service area,” BN Ramakrishna, director of Istrac, told TOI.
A source said that personnel from Indian navy, air force and coast guard — whose teams eventually carry out the rescue operations — are given periodic orientation and training at Istrac in Bengaluru, which helps them execute SAR.
How it works
The INMCC consists of a mission control centre (MCC), local user terminals (LUTs) and beacon registration database service.
All Indian users of beacons are required to register their beacons, along with the personal information — to be used by the rescue coordination centres for rescue operations — on the INMCC website hosted by Istrac. As on date, 1,048 Indian users have registered 18,501 beacons.
According to Istrac, signals are picked up by the INMCC from these distress beacons classified into three categories: Emergency location transmitter (ELTs) for aviation use; emergency position indicating radio beacon (EPIRBs) for maritime use and personal locator beacon (PLBs) for personal use.
The beacons operate at 406MHz frequency and SAR payloads on satellites in low-altitude orbits, geostationary orbit and medium-altitude orbits detect the signals transmitted by them.
Ground receiving stations — local users terminals — spread across the world receive and process satellite downlink signals to generate distress alerts. A network of MCCs established worldwide are then used to disseminate distress alerts and location information to SAR authorities.
Ramakrishna added INMCC has a major role in providing distress alert information to SAR Point of Contacts (SPOCs) of the seven neighbouring countries. “INMCC receives distress alert data pertaining to these countries through LUTs and other MCCs. These alerts are disseminated to their respective rescue coordination centres.”