In the third and final stage of orbit-raising operation conducted today at 09:39
am IST (April 14, 2003) from Master Control Facility (MCF), Hassan, INSAT-3A
has been placed in its Geo Stationary Orbit (GSO). The manoeuvre was completed
by firing the 440 Newton Liquid Apogee Motor on board the satellite for a
duration of 3 minute and 41 seconds. The satellite has achieved an orbital
period of 23 hours and 48 minutes and is continuously visible to the MCF,
Hassan. INSAT-3A is now moving towards its geostationary orbital slot with the
planned drift rate of 2 degree per day. It is expected to reach its orbital
slot of 93.5 degree East Longitude in the next five days.
The 440 Newton Liquid Apogee Motor (LAM), which was used to conduct INSAT-3A
orbit raising manoeuvres, has performed well. It enabled taking the satellite
from its Geostationary Transfer Orbit (GTO) (860 km perigee and 36,000 km
apogee with an orbital inclination of 2 degree with respect to the
equatorialplane) to its present 36,000 km circular orbit with zero degree
inclination. The LAM was fired for a total duration of 130 minutes and 23
seconds in three phases on April 11, April 12 and April 14. A total velocity of
1.411 km per second was added by LAM at the Apogee point of the orbit to take
the satellite from GTO to GSO.
INSAT-3A had 1,603 kg propellant at the time of its injection into GTO by
Ariane-5 launch vehicle on April 10. After orbit raising operations, it has 505
kg of propellant remaining that is sufficient to arrest the drift and park it
at its orbital slot as well as maintain the satellite in its orbit and
controlling its orientation during its designed life of 12 years.
The deployment of the solar array and the antenna is planned for tomorrow. All
subsystems on the satellite are working normally.