ISRO head: Recall of India satellite prevented a failure

K. Sivan, the chairman of ISRO, India’s space agency, revealed today that the decision to recall GSAT-11 in April just as it arrived in French Guiana for a May Ariane 5 launch prevented a major failure.

They had decided to recall it because two previous satellites had failed, using almost identical equipment. As he notes,

GSAT-11 had the same set of power system configuration that two older satellites had. RISAT-1 died prematurely and GSAT-6A lost communication contact soon after launch on March 29 because of suspected power system failure, harnesses etc… We had just sent GSAT-11 [to Guiana] and no one was sure if the same issue was there in GSAT-11,” he said.

Checks found that the provision or “margin” for the deployment of the solar panel was much smaller than was required. “Had it gone in that configuration, the panel [which generates power for the 15-year life] would not have deployed in space. The satellite would have been a failure.”

Because the recall cost money and delayed the launch significantly, it required the ability to look at the engineering honestly and not let politics interfere. Sivan and his managers did that, which speaks well for future space engineering from ISRO.

India recalls communications satellite, postponing launch indefinitely

India’s space agency ISRO yesterday recalled its largest ever communications satellite, GSAT-11, from French Guiana, where it was being prepared for a May Ariane 5 launch, citing a need to check the satellite’s systems.

Though no specific reason was given for the recall, which will postpone the satellite’s launch indefinitely, it likely is related to the March failure in orbit of India’s GSAT-6A satellite.

ISRO lost communication contact with its GSAT-6A communication satellite soon after it was put into orbit on March 29.

ISRO suspects the failure of the power systems in the satellite for the loss of communication link. “The satellites are powered by solar panels that charge the onboard batteries. The batteries are fully charged when the satellite is loaded on to the rocket. Even if there is a problem with the solar panel, then the battery power should have kicked in. Here the entire power system of the satellite seems to have failed,” one space expert told IANS earlier.

According to experts, the power system could have failed due to some short circuiting or arcing resulting in what is known in the space terminology ‘loss of lock’ or loss of contact with the ground station.

The head of ISRO is a well-trained engineer who has worked in the trenches. I suspect he decided the problems with GSAT-6A demanded a more detailed systems check on GSAT-11 prior to launch. And even if it wasn’t his specific decision, the willingness to make such a decision I think indicates a great deal of maturity in the present culture at ISRO. It might be embarrassing to make such a recall, but it is far better to do so beforehand than after an unrecoverable failure in space. That they are willing to face this embarrassment to avoid a future failure is something laudable.