ISRO eyes share in global small satellite market with SSLV launch on August 7

The Indian Space Research Organization on August 7 will launch its smallest commercial rocket — SSLV — to put in orbit two satellites, offering cheap rides to space and eyeing a share in the burgeoning small satellite launch market.

The 34-metre Small Satellite Launch Vehicle (SSLV) is 10 metres shorter than ISRO’s warhorse rocket Polar Satellite Launch Vehicle (PSLV) and can put payloads up to 500 kg into 500 km planar orbit.

Unlike the PSLV, the SSLV uses solid fuel hydroxyl-terminated polybutadiene to fire the three stages of the rocket which takes the payloads to the desired altitude.

The liquid-propelled Velocity Trimming Module (VTM) then inserts the satellite into orbit. In its maiden launch, the SSLV will place in orbit the 145 kg Earth Observation-2 satellite and AzaadiSat, a 8-kg cubesat designed by 750 girl students from government schools across the country to mark the 75th anniversary of Independence.

According to ISRO officials, the SSLV has a low turnaround time and can be assembled within a fortnight, allowing the space agency to provide launch on demand service in the fast growing low earth orbit launch sector.

The SSLV D-1 will soar into the skies at 9:18 am from the Satish Dhawan Space Centre at Sriharikota on Sunday and place in orbit the two payloads at the end of its 13.2 minute flight.

The SSLV is 34 metres in height with a vehicle diametre of two metres and a lift off mass of 120 tonnes. The PSLV, on the other hand, is 44 metres tall, 2.8 metres in diametre and a lift-off mass of 320 tonnes. It has the capacity to put up to 1,800 kg payloads into orbit.

"The SSLV is a ready to transfer vehicle with modular and unified systems and with standard interfaces for end-to-end industrial production," an ISRO official said. The key features of SSLV include a booster motor segment with open joint configuration to minimise segment assembly and launch integration time.

It also has a unified interstage joint configuration to enable quick integration and launch, and miniaturised low cost avionics system with industrial commercial off-the-shelf components.

The SSLV also has multi-satellite accommodation with a multi-satellite adaptor deck and a digital control system with fully indigenous electro-mechanical actuators.