Insat 3E placed in intermediate orbit

Insat 3E placed in intermediate orbit

MUMBAI: It took over a month to happen, courtesy technical snags, but Isro satellite Insat 3E was finally launched on board Ariane 5's Flight 162. The launch took place on 28 September at 4:44 am IST.


In the first critical orbit-raising manoeuvre, conducted at 6:57 am (IST) this morning, the 440 Newton Liquid Apogee Motor (LAM) on board Insat-3E was fired for 82 minutes by commanding the satellite from Master Control Facility (MCF), Hassan. With this LAM firing, Insat-3E perigee (closest point to the earth) has been raised from 649 km at the time of launch to 14,970 km at present. The apogee (farthest point to earth) remains at 35,900 km and the inclination of the orbit with respect to the equatorial plane has been reduced from 7 deg. at the time of launch to the present 1.9 deg. The orbital period is 15 hours 30 minutes.
The launch of Insat-3E is a major boost to telecom and television services in the country. The fourth satellite in the Insat series, the spacecraft is equipped with 24 normal C-band and 12 extended C-band transponders, swelling the present capacity of nearly 95 transponders in the five already operational Insat satellites.
The Insat system is the mainstay for communication and broadcasting in the country. With an operational lifetime of 15 years, Insat-3E is expected to augment the present capacity of Insat for communication and TV services, reports Press Trust of India.
The 2750 kg satellite with a life span of 15 years will provide telecommunications and television transmission services for the Indian subcontinent. It carries 24 C-band transponders, which provide an Edge Of Coverage-Effective Isotropic Radiated Power (EOC-EIRP) of 38.5 dBW. It also has 12 upper extended C-band transponders, India beam coverage, providing an EOC-EIRP of 38 dBW.
It will be positioned at 55 degrees East. INSAT-3E is being tracked, monitored and controlled by the Master Control Facility (MCF) at Hassan in Karnataka.
In the coming days, INSAT-3E will be raised 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 three-axis stabilised mode. This will be followed by trim manoeuvres to take the satellite to its designated orbital slot. The payloads will be subsequently checked out before the commissioning of the satellite.
Yesterday, MCF acquired the first signals from Insat-3E at 5:14 am IST. The initial health checks on the satellite indicated that the satellite's performance was normal. MCF subsequently issued tele-commands to the satellite to make the satellite's earth viewing face orient towards earth. The calibration of the gyros on board the satellite was also carried out.


During the initial phase of INSAT-3E's operations, MCF will also utilise Inmarsat's Telemetry, Tracking and Command (TTC) ground stations at Beijing (China), Fucino (Italy) and Lake Cowichan (Canada). The satellite's orbit is being precisely determined by continuous ranging from the participating ground stations.
INSAT-3E was the 11th Indian satellite to be orbited by Europe's launcher. Arianespace and Isro have worked together for over 22 years, starting with the 1981 launch of India's first satellite, Apple. INSAT-3E was the fourth satellite to be launched in the INSAT-3 series.
In addition Flight 162 also launched Eutelsat's e-Bird. The mission's third payload, ESA's Smart-1 lunar probe, was successfully injected into an orbit that will take it to the Moon.
Flight 162 was the standard Ariane 5G vehicle's 13th successful launch, and it marked Arianespace's fourth lift off in 2003. Two other Ariane 5 flights were performed on 9 April and 11 June which were preceded by the final launch of an Ariane 4 on 15 February.