THE GSAT-6A MISHAP
The failure to nudge the military grade communications geosynchronous satellite GSAT-6A into the intended orbit on April 1 is a significant setback for the Indian Space Research Organisation (ISRO). While the Geosynchronous Satellite Launch Vehicle Mark II (GSLV Mk-II) launcher did ferry the 2,100 kg satellite—built at a cost of Rs 270 crore—into space, the planned transfer into the designated geosynchronous orbit did not happen. The onboard motors failed after it had nudged the spacecraft twice to stay on course, suggesting that a power failure snapped the communications link before the final nudge to place it in the specified perch of 35,800 km over the Equator.
Failure analysis teams will assess what triggered the ‘blackout’. Preliminary analysis suggested all was well with GSAT-6A’s systems and it went into safe mode due to an ‘external disturbance’. ISRO is examining why the power system malfunctioned, including the effect of a solar storm and the new lithium ion cells used in the satellite. ISRO ground controllers say they have a mechanism to re-establish communication links and will make more attempts before formally declaring the launch a ‘failure’. A team led by ISRO Satellite Centre ex-director P.S. Goel will look into the anomaly.
The loss of GSAT-6A, with a planned life of 10 years, is significant as it belonged to the high power S-band communications satellite genre. The high power, facilitated by a three times larger antenna, would have allowed signals to be received on the ground through even handheld devices. The Defence Research and Development Organisation (DRDO) has been working on supplying security forces in remote areas with such devices. GSAT-6A was to complement GSAT-6, which has been providing services since its launch in 2015. ISRO-commissioned heavy duty communications satellites are critical to improving mobile internet and broadband speed, where India lags.
GSAT-6A is ISRO’s second failure in recent months and, coincidentally, was the first launch after K. Sivan took charge as the organisation’s chairman. The mishap, however, will not be a deterrent to future missions, including the launch of the Indian Regional Navigational Satellite System (IRNSS-1I) and the Chandrayaan-2 mission.