GSAT-12 positioned into final geo-synchronous orbit
20 Jul 2011
Hassan, Bangalore: India's communication satellite GSAT-12, placed in a sub-geo-synchronous transfer orbit (sub-GTO) on 15 July by ISRO's PSLV-C17 mission, has finally reached its designated home in a circular geo-synchronous orbit at an altitude of 36,000 km on Tuesday.
The Polar Satellite Launch Vehicle (PSLV-C17), a booster XL version of the workhorse PSLV, had hoisted the 1,410 kg GSAT-12 into the sub-GTO position with an apogee of 21,020 km and a perigee of 284 km.
Once in the sub-GTO position the satellite's onboard liquid apogee motor (LAM) was fired once each day in the period 16-19 July to raise the satellite into its designated geo-synchronous slot at an altitude of 36,000 km.
The Master Control Facility (MCF) at Hassan in Karnataka fired the motors on 16 and 17 July to take the satellite's apogee from 21,020 km to 36,000 km when the satellite was at its perigee. Similarly, commands were issued on 18 and 19 July to the onboard LAM to fire which raised its perigee from 284 km to 36,000 km.
ISRO officials said it was a challenging operation. They confirmed all sub-systems on board the satellite were functioning normally.
The satellite has now made it to its final, circular geo-synchronous orbit of 36,000 km.
