ISRO’s ‘baby rocket’ and it’s umbilical cord with Thiruvananthapuram

Fully designed and developed by ISRO facilities in Kerala capital

When the Small Satellite Launch Vehicle (SSLV) lifts off from Sriharikota on its maiden developmental flight, Thiruvananthapuram, where India’s space programme took off in the 1960s, will have much to cheer about.

Slated for launch from the Satish Dhawan Space Centre on August 7, the ‘baby rocket’ has been fully designed and developed by the Indian Space Research Organisation (ISRO) facilities in Thiruvananthapuram with industry participation.

The Vikram Sarabhai Space Centre (VSSC) here in Thumba, which is ISRO’s lead unit on launch vehicles, was responsible for the design and development of the three-stage SSLV. The Liquid Propulsion Systems Centre (LPSC) at Valiyamala in the district developed the Velocity Trimming Module (VTM) for the SSLV, VSSC director S. Unnikrishnan Nair told The Hindu.

VTM will be used to insert satellites – the SSLV-D1 mission will have two on board – into the chosen orbit with precision in inclination and velocity. ‘‘The VTM will enable minor course corrections when placing a satellite in orbit,’‘ said Dr. Unnikrishnan Nair.

At 34-m tall with a lift-off mass of 120 tonnes, SSLV is 10 m shorter than the Polar Satellite Launch Vehicle (PSLV) and about 200 tonnes lighter. On its first developmental flight, the SSLV-D1 will carry the 135-kg EOS-02 satellite as the main payload and the much smaller AzaadiSAT satellite.

What makes the SSLV, which can handle satellites in the 10 kg-500 kg range, attractive is the fast turnaround time. ‘‘You can finish its integration in a week, whereas you need one-and-a-half to two months to assemble a PSLV or the Geosynchronous Satellite Launch Vehicle (GSLV). The SSLV is a launch-on-demand vehicle,’‘ he said.

This advantage comes from the fact that the SSLV is a solid propulsion rocket, with all its three stages powered by a Hydroxyl-terminated polybutadiene (HTPB)-based propellant. The small VTM, however, uses liquid propulsion.