Key valve in satellite launched in 100th mission suffers glitch, Isro weighing options

BENGALURU: The satellite Isro launched in its much celebrated 1ooth launch mission on Jan 29 has suffered a failure of a valve designed to supply the oxidiser to the liquid apogee motor (LAM) onboard the spacecraft, multiple sources have confirmed to TOI.
What this means is that the space agency has been unable to operate the LAM, which is critical for the spacecraft to change orbits and reach its final intended orbit for operations. The satellite, as of Sunday, continues to remain in a geosynchronous transfer orbit (GTO), which is an elliptical orbit used to insert satellites before they are moved to their intended final orbits.
Navigation satellites need a near circular orbit to operate optimally, and without the firing of LAM, that will be difficult for Isro to achieve. “The issue with the valve was detected after the launch put the satellite in the GTO. Orbit correction manoeuvres have not been carried out since launch,” a source said.
Another source pointed out that the valve was “not opening” as it was intended to, “preventing LAM from getting the supply of the oxidiser, without which the motor cannot be fired”. The source added that multiple attempts to resolve the issue have not been able to get the “desired outcome”.

A third source said that a committee looking into the issue has met multiple times in the past four days and that a final decision on how to operate the satellite may be taken late Sunday. “All other systems on the spacecraft are fine. It is fully healthy, there’s full electrical generation and we are able to control the satellite,” the source said.
Sources added that the space agency may consider operating the satellite from an available orbit, but a final decision on the same was pending. “We are able to exploit the signal,” one of the sources said.
The NVS-02 satellite, part of India’s Indian Regional Navigation Satellite System (IRNSS) with an operational name NavIC or Navigation with Indian Constellation. It is part of the second generation of NavIC satellites and carries an indigenous atomic clock.
TOI had contacted Isro chairman V Narayanan for a comment early on Sunday. By evening, Isro issued an official statement:
"Subsequent to the launch, the solar panels on board were successfully deployed and power generation is nominal. Communication with the ground station has been established. But the orbit raising operations towards positioning the satellite to the designated orbital slot could not be carried out as the valves for admitting the oxidizer to fire the thrusters for orbit raising did not open," an Isro statement read.
"The satellite systems are healthy and the satellite is currently in elliptical orbit. Alternate mission strategies for utilising the satellite for navigation in an elliptical orbit is being worked out," it added
Soon after the launch, Isro chairman V Narayanan had said: “The NavIC system is evolving as the backbone of indigenous satellite navigation ecosystem of the Indian region. The first batch of IRNSS satellites launched in the previous decade has been successful in establishing the PNT (positioning, navigation, and timing) services.”
“...Today, many applications based on NavIC spanning from strategic users, tracking of shipping vessels, time synchronisation, time tracking and safety of life alert dissemination have been accomplished. I congratulate all the teams involved in making the launch successful. In the coming days we will forward to orbit raising operations of the satellite and deployment of the satellite in the assigned orbit,” he had added.