SSLV-D2 places three small satellites in orbit

Union Home Minister Amit Shah congratulated the team after the launch. He tweeted, “Kudos to team @isro. India creates history with the successful launch of the SSLV-D2 / EOS-07 mission on the advent of its Amrit Kaal. This launch allows India to send up to 500kg objects in Low Earth Orbits paving the way for self-reliance in space programs.”

There was silent anticipation by the scientists for a few moments when the final liquid propellant-based, velocity-trimming module – developed for accurately positioning the satellites in orbit – reached the intended altitude but the satellites’ separation did not begin. The separation happened a few seconds later than what the mission brochure had mentioned – the first satellite, EOS-07, separated at 801 seconds instead of 785 seconds after flight, Janus -1 at 903 seconds instead of 880 and Azadisat 2 at 923 seconds instead of 900. There are usually slight deviations in every mission.

The first flight of the launch vehicle on August 7, 2022, could not put the satellites in the intended orbit, despite all three solid stages performing as needed. Within six months, a failure analysis was conducted and changes were made to the equipment bay, the separation mechanism, and the on-board system for recognising faulty sensors. Five new pieces of hardware were tested before the second flight of the new launch vehicle to ensure its success.

“SSLV had its maiden flight, SSLV-D1. We had a narrow miss because of a shortfall in velocity and we are happy to report that we analysed the problems in SSLV-D1, identified the corrective action implemented at a very fast pace, qualified all those new systems and went through a large amount of simulation and studies to ensure that the vehicle will become a success this time,” said Somanath.

He said the satellites precisely reaching the intended orbits meant the new, cost-effective guidance and navigation system used in the launch vehicle as well as the electronics performed well.

SSLV mission director S Vinod said a small team had worked hard since 2018 to design, realise, fabricate and test the new rocket, adding that “finally it had to also overcome Covid phase” to reach the launch pad last year. He said despite a setback in August last year, the team worked hard to make the changes suggested by review committees and came up with “five new hardware and new separation system” in five months.