ISRO’s Small Satellite Launch Vehicle (SSLV) lifted off from the spaceport in Sriharikota at 9.18 AM. But almost immediately, something went wrong. Minutes after launch ISRO chairman S Somanath said that the SSLV D1 mission suffered “data loss” at a terminal stage. And not long after that, ISRO announced that the two satellites deployed by the launch vehicle would not be usable. Here is what went wrong.
“All stages performed as expected. The first stage performed and separated, the second stage performed and separated, the third stage also performed and separated, and in the terminal phase of the mission, some data loss is occurring. We are analysing the data and we will come back on the status of the satellites as well as the vehicle performance soon,” said Somanath from Mission Control Centre, minutes after the launch, according to PTI.
“SSLV-D1/EOS-02 Mission update: SSLV-D1 placed the satellites into 356 km x 76 km elliptical orbit instead of 356 km circular orbit. Satellites are no longer usable. Issue is reasonably identified. Failure of a logic to identify a sensor failure and go for a salvage action,” said the space agency in a tweet. The mechanism put in place to identify a sensor failure did not work and thereby, the launch vehicle failed to initiate a salvage action that would have made deviations.
What was the rocket carrying
The rocket was carrying EOS-02 which is an Earth observation satellite. It was also carrying AzaadiSAT, a student satellite. It went on to complete all stages of the lift-off successfully until the terminal stage, which is where ISRO scientists observed the “data loss”. After that, SSLV placed the satellites in an elliptical orbit, instead of a circular orbit, rendering them, “no longer usable.”
(1/2) SSLV-D1/EOS-02 Mission update: SSLV-D1 placed the satellites into 356 km x 76 km elliptical orbit instead of 356 km circular orbit. Satellites are no longer usable. Issue is reasonably identified. Failure of a logic to identify a sensor failure and go for a salvage action
— ISRO (@isro) August 7, 2022
Due to this malfunction, the launch vehicle put the satellites into a 365km x 76 km elliptical orbit instead of the intended 365 km circular orbit, meaning that the science objectives of the mission could not be completed.
Now, a committee will analyse the launch and make recommendations for improvements. After implementing these recommendations, ISRO will come back for another attempt with the SSLV-D2 mission.