ISRO plans biggest ever spacecraft by 2014

ISRO plans to launch its biggest ever spacecraft, the 5,000-kg GSAT-11, by 2014.

The advanced communication satellite, GSAT-11, will be double the capacity and size of the present buses, and will be built over the next two years.

GSAT-11 will have 32 transponders in the Ka and Ku bands, ISRO's just-released annual report for 2011-12, has revealed.

ISRO is banking on this large, one-shot boost to its flagging capacity. Only half of its present capacity — or 80 transponders — comes from its fleet of INSAT /GSAT communications satellites. The rest are leased on foreign satellites.

The present capacity of 175 transponders is around half of its requirement. It has been looking around to fill it. To date, GSAT-8 is the biggest national craft to be built. The 3,600-kg piece was launched by a European Ariane rocket last May.

Mr S. Satish, ISRO's spokesman, said the spacecraft proposal was due for formal approval. He said the 5k advanced craft would go up on a ‘procured' or outside launch. ISRO has traditionally used European Ariane launchers to put its larger satellites into orbit.

A normal 2-3k satellite costs around Rs 200 crore to assemble; and around the same for launch. For GSAT-11 and its launch, it could be an estimated Rs 700-800 crore.

“Subsystem level preliminary design review has been completed. The qualification programme for all new elements onboard GSAT-11 has been initiated,” the report says.

ISRO's medium-lift rocket under development, the GSLV, can launch up to 2,000-kg satellites into the middle-earth orbits that are suited for communication satellites — 36,000 km up above the earth.

The rocket is being perfected and has yet to be put fully in service. The GSLV MkIII, meant to lift heavier satellites of 4-6 tonne, looks far from GSAT-11's schedule.

Upcoming satellites would be a mix of 1k, 2k and 3k satellites, so that smaller ones like the 1,400-kg GSAT-12 can be launched quickly on the PSLV, he said.