JOIN USIsro has lost contact with the country's newest communication satellite GSAT-6A since Saturday.
The space agency had successfully completed the second orbit raising operation.
Though there were murmurs within Isro and the scientific community about the satellite going off the radar since Saturday noon, the Bengaluru-headquartered space agency confirmed the development only on Sunday.
Speculation that communication with the satellite could have been lost began after Isro went silent without putting out the customary update on its movement.
"The second orbit raising operation of GSAT-6A satellite has been successfully carried out by LAM Engine firing for about 53 minutes on March 31, 2018, in the morning. After the successful long-duration firings, when the satellite was on course to the normal operating configuration for the third and the final firing, scheduled for April 1, 2018, communication from the satellite was lost," Isro said in its update posted on its website a little before Sunday noon.
"Efforts are underway to establish the link with the satellite," the update said, without giving further details.
Though scientists and officials were tight-lipped about the satellite's status, sources said power failure could have been the reason behind the satellite losing contact with the base.
They also said the satellite may be irretrievable though Isro still maintains that efforts are on to establish the link.
The development comes as a major setback for Isro since the GSAT-6A satellite, that was built with a lifespan of 10 years, could have helped the armed forces in terms of communication.
If the Isro fails in retrieving the satellite, it will be its second failure in seven months after losing navigation satellite IRNSS-1H in August.
The development is also a personal setback for Isro chief Dr K Sivan as this was the first launch after he assumed office in January.
The 2,066-ton satellite was built at a cost of Rs 270 crore and it was considered crucial since the Isro, for the first time, inducted high thrust Vikas engine and electromechanical actuation system.
These systems are to be used in the future missions, including India's second moon mission, Chandrayaan-II.
The setback also comes at a time when the Isro is planning for 10 launches by the end of 2018, including Chandrayaan-II and other communication and navigation satellites.