ISRO's latest satellite, INSAT-4B, was successfully launched early this morning
(March 12, 2007) by the European Ariane-5 ECA launch vehicle of Arianespace.
The 3,025 kg INSAT-4B is the second satellite in the INSAT-4 series. An
identical satellite, INSAT-4A, was launched by Ariane-5 on December 22, 2005.
With 12 high power Ku-band transponders and 12 C-band transponders, INSAT-4B
will further augment the INSAT capacity for Direct-To-Home (DTH) television
services and other communication and TV services.
The 31st flight in Ariane-5 series, carrying ISRO's INSAT-4B and its
co-passenger, Skynet-5A of EADS Astrium, lifted off at 03:33 am Indian Standard
Time (IST) from Kourou, French Guyana. About 30 minutes after lift-off,
INSAT-4B was placed in the Geosynchronous Transfer Orbit (GTO) in 3-axis
stabilised mode. INSAT-4B is now orbiting the earth with a perigee (nearest
point to earth) of 243 km and an apogee (farthest point to earth) of 35,876 km
and an inclination of 4.52 deg with respect to the equator. The orbital period
is about 10 hours 34 minutes.
The Master Control Facility (MCF) at Hassan in Karnataka acquired the first
signals from INSAT-4B at 4:02 am IST. The initial checks on the satellite have
indicated normal health of the satellite. MCF subsequently issued commands to
the satellite to make the earth viewing face to orient towards earth. The
calibration of the gyros on board the satellite was also carried out.
INSAT-4B is being tracked, monitored and controlled from MCF. During the initial
phase operations, MCF also utilises INMARSAT Organisation's Telemetry, Tracking
and Command (TTC) ground stations at Beijing (China), Fucino (Italy) and Lake
Cowichan (Canada) besides the ISRO Telemetry, Tracking and Command (ISTRAC)
Network station at Biak in Indonesia. The satellite's orbit is being precisely
determined by continuous ranging from the participating ground stations.
In the coming days, INSAT-4B will be manoeuvred to its final geostationary
orbit, which is about 36,000 km above the equator, by firing its 440 Newton
Liquid Apogee Motor (LAM). When the satellite reaches near geosynchronous
orbit, deployment of its solar panels and the two antennas will be carried out
and the satellite put in its final 3-axis stabilised mode. This will be
followed by trim manoeuvres to take the satellite to its designated orbital
slot at 93.5 degree East longitude where it will be co-located with INSAT-3A.
The payloads will be checked out before the commissioning of the satellite.
INSAT-4B carries the following payloads: