INDIA: The first small satellite launch vehicle (SSLV) of the Indian Space Research Organization (ISRO), carrying the students’ satellite AzaadiSAT and the earth observation satellite EOS-02, didn’t go as planned on Sunday.
The SSLV-D1 failed the mission by putting the satellites in an elliptical orbit rather than a circular one, which made them “no longer usable,” as ISRO later stated in a statement.
ISRO stated: “Instead of putting the satellites into a 356 km circular orbit, SSLV-D1 placed them into a 356 km x 76 km elliptical orbit. We can no longer use satellites. The problem is correctly detected. The divergence was caused by a lack of logic in failing to recognise a sensor failure and take salvage action.“
What went wrong
On Sunday at 9.18 a.m., Sriharikota saw the launch of ISRO’s first small satellite launch vehicle (SSLV).
The space agency’s mission was designed to increase its share of the market for small launch vehicles because it could put the satellites into Low Earth Orbit.
According to sources, the issue seemed to be the velocity trimming module (VTM) at the SSLV’s terminal stage. At 653 seconds after launch, the VTM was scheduled to have burned for 20 seconds in accordance with the launch profile. It only burned for 0.1 seconds, though, depriving the rocket of the necessary height boost.
After the VTM fire, the rocket’s two satellites—the secondary AzaadiSAT student satellite and the principal EOS-2 Earth-observing satellite—separated from the rocket. As a result, they are probably no longer on their intended orbital routes and have instead entered an elliptical orbit.
When updating the public on the launch on Sunday at 11:43 a.m., the space agency tweeted, “All the stages performed normally. It was administered to both satellites. However, the orbit was less stable since it was achieved than was anticipated.”
At 2:48 p.m., ISRO announced that it had determined the mission’s failure and reason.
In a later video announcement, S Somanath, the chairman of ISRO, said: “The vehicle took off beautifully with the burning of the first stage, and the subsequent S2 and S3 behaved extremely well. The performance of the mission was excellent, and the satellites were ultimately separated when they reached the orbit at the height of 356 km. But afterward, we discovered a discrepancy in the satellites’ orbital positions.”
“The chairperson went on to say that when a satellite is deployed in such an orbit, it is unable to stay on course for very long and eventually falls off. The satellites have already left that orbit and are no longer functional,” according to Somanath.
The ISRO claims that the deviation was caused by “failure of logic to identify a sensor failure and move for salvage operations”. A committee would review and make suggestions. ISRO will return with SSLV-D2 soon after the recommendations are implemented.
Also Read: ISRO Successfully Launches Its New SSLV-D1 Rocket Carrying a Student Satellite