ISRO’s retrieve-reuse formula to bring down rocket costs

As part of its plan to bring down the cost of satellite launch vehicles (rocket), the Indian Space Research Organisation (ISRO) has embarked on a research focussing on the retrieval of the ‘first stage’ of the satellite launch vehicle after it gets separated from the other stages. 

The Geosynchronous Satellite Launch Vehicle (GSLV) has three stages whereas Polar Satellite Launch Vehicle (PSLV) comes with four stages. The first stage of the rocket, which has hydroxyl-terminated polybutadiene based (HTPB) fuel loaded in it, provides the launcher the high thrust needed for lift off of the launch vehicle. 

Speaking to DT Next on the sidelines of the PSLV C-31 mission, Dr K Sivan, director of ISRO’s Vikram Sarabhai Space Centre (VSSC) at Trivandrum, said that by retrieving and reusing the first stage of the launch vehicle more than 25 per cent of the cost of launch vehicle could be saved. 

“We want to bring the first stage of the rocket to earth and save one-fourth of the vehicle’s cost, for which we (ISRO) are doing research of how to retrieve the first stage and reuse it again for the next missions. We are hopeful of completing the project within three years,” he said. 

Pointing out that as the cost of other stages do not cost a lot to ISRO, Dr Sivan said that they would not attempt to recover stages other than the first one. Terming PSLV C-34 and C-35 mission as milestone for ISRO, the VSSC director said that ISRO would demonstrate its capability to place two satellites in different orbits by reigniting the engine in the last stage after the first satellite is placed in a particular orbit and the second one in a different orbit. 

“We did an experiment in PSLV C-29 mission last month by reigniting the engine in the last stage for four seconds after all the six satellites were placed in their orbit. The experiment turned out to be a success. So we want to demonstrate the capability in the C-34 mission in April and in the C-35 mission we will actual place two satellites in different orbits,” he said.