SEOUL, South Korea — India’s Small Satellite Launch Vehicle (SSLV) put three satellites into low Earth orbit Feb. 9, in the nation’s first orbital launch this year.
It was the rocket’s second flight and first successful one. The inaugural launch in August suffered an anomaly in the rocket’s kick stage, resulting in a velocity shortfall. Indian scientists traced an unexpectedly strong shock that took place during the separation of the second stage as the key cause of the malfunction and replaced the rocket’s stage separation system with one that produces less shock.
SSLV-D2’s payloads
The three-stage SSLV, capable of sending up to 500 kilograms of payload to low Earth orbit, lifted off at 10:48 p.m. Eastern, from the Satish Dhawan Space Centre, carrying a trio of satellites. The primary payload, EOS-07, was a 156-kilogram Earth observation satellite for the Indian Space Research Organisation (ISRO), and the two smaller spacecraft that hitched a ride were the Janus-1 6U cubesat for U.S. company Antaris and the 8U cubesat AzaadiSAT-2 developed by Indian students, according to an ISRO mission description.
Live footage showed the 34-meter rocket, decorated with India’s national flag, soaring into the air. The flight proceeded as planned — the first stage separation took place 128 seconds after liftoff, the second stage separation at 386 seconds and the third stage separation at 675 seconds. The rocket’s kick stage, called the Velocity Trimming Module (VTM), deployed the satellites one by one between 808 and 923 seconds after liftoff.
“Congratulations to the space community of India. So, we have a new launch vehicle, small satellite launch vehicle SSLV,” said ISRO chairman S. Somanath in a livestreamed post-launch speech. He noted that the three satellites had been put into 450 kilometers circular orbit “very accurately.”
ISRO developed SSLV with the aim of providing cheaper and more flexible access to space, compared to its two operational vehicles, the Polar Satellite Launch Vehicle (PSLV) and the Geosynchronous Satellite Launch Vehicle (GSLV). To that end, SSLV was designed to be configured with a simple modular interface, and the vehicle’s assembly can be done horizontally and vertically.
What’s Ahead
The Feb. 9 flight was India’s first space launch of 2023, with ISRO planning at least three launches in the first quarter. Coming up next is the launch of 36 communications satellites for British company OneWeb in March on a GSLV Mark 3 rocket. It would be the second and last launch of OneWeb satellites on an Indian rocket under a contract signed in April between OneWeb and New Space India Limited, ISRO’s commercial arm. ISRO said the third planned mission will use Polar Satellite Launch Vehicle (PSLV).
