The Indian Space Research Organization (ISRO) has raised its 3.4-ton GSAT-10 communication satellite closer to its final geostationary orbit by firing the spacecraft’s liquid apogee motor on Oct. 1.
“In the second orbit-raising exercise, the satellite has been placed at 31,822 km perigee [lowest point] and 35,734 km apogee [highest point], which is closer to its designated geostationary orbit,” an ISRO official says. The first orbit-raising burn took place Sept. 30 A third firing is planned as well, to place the satellite in its final orbit by Oct. 3.
The GSAT-10 satellite, India’s 101st space mission, was successfully lofted on Sept. 29 aboard an Ariane 5 rocket from the European spaceport at Kourou in French Guiana.
“After a smooth countdown, the Ariane 5 launch vehicle lifted off right on schedule at the opening of the launch window at 2:48 a.m. India time on Sept. 29,” the official says. GSAT-10 was put into an elliptical Geosynchronous Transfer Orbit after a flight of 30 min. and 45 sec.
Preliminary health checks on various subsystems of the satellite such as power, thermal, command, sensors and controls were carried out prior to the launch.
“All the parameters were found satisfactory. Following this, the satellite was oriented toward the Earth and the Sun using the onboard propulsion system. The satellite is in good health,” the ISRO official says. “It is planned to experimentally turn on the communication payloads in the second week of October. The satellite’s two solar panels and two reflectors will also be deployed after it reaches the designated slot Wednesday.”
The space agency’s master control facility at Hassan in southern Karnataka took over the command of the satellite after its injection into its initial orbit to monitor the spacecraft’s health and the subsequent orbit-raising. GSAT-10 will be positioned at 83 deg. East, along with INSAT-4A and GSAT-12.
The three-axis stabilized geostationary satellite, which has an intended 15-year lifespan, was developed for India’s communications requirements and to augment current services. It carries 12 regular C-band, six extended C-band and 12 Ku-band transponders.
The cost of GSAT-10, including its launch and insurance, is 7.5 billion rupees (more than $135 million). GSAT-10, weighing 3,400 kg (7,500 lb.) at liftoff, is the heaviest spacecraft ISRO has built. The satellite will become operational by November.
The launch of GSAT-10, earlier scheduled for Sept. 22, was postponed a week due to a minor error in the Ariane 5 rocket. Last year, India successfully lofted two communications satellites, GSAT-8 and GSAT-12, which are intended to boost direct-to-home services in the country.
GSAT-10 photo: ISRO