Insat-3A placed in intermediate orbit

Insat-3A placed in intermediate orbit

Insat-3A

MUMBAI: Insat-3A, which was launched by Ariane-5 of Arianespace yesterday from Kourou, French Guiana is now orbiting at 11,500 km above the earth's surface.
 
 
Isro's Master Control Facility (MCF) in Hassan, Karnataka, directed the satellite's first critical orbit raising manoeuvre at 7 am (IST) this morning. Insat 3-A's 440 Newton Liquid Apogee Motor (LAM) was fired for 73 minutes 42 seconds, raising the satellite's perigee (closest point to the earth) 860 km at the time of launch to 11,500 km at present. The apogee remains at 36,000 km and the inclination of the orbit with respect to the equatorial plane has been reduced from 2 deg. at the time of launch to the present 0.9 deg. The orbital period is 14 hours 30 minutes.
The Ariane5 lifts off from the Kourou spaceport in French Guiana early Thursday (IST), 10 April 2003.
Insat-3A, which was launched by Ariane-5 of Arianespace yesterday from Kourou, French Guiana, had gone out of visibility of MCF, Hassan, at 3.20 pm yesterday and came within its visibility at 2.16 am IST this morning.

According to Isro, all systems on board the satellite were functioning normally. The satellite was scheduled to go out of MCF visibility again at about 1.44 pm IST this afternoon and come within its visibility at 7 am tomorrow. The second orbit manoeuvre is planned around 1 pm tomorrow.

Insat-3A is being tracked, monitored and controlled from MCF. During the initial phase of Insat-3A operations, MCF also utilises Inmarsat's 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 Telemetry, Tracking and Command (TTC) ground stations.

MCF is responsible for initial and in-orbit operation of all Isro's geo-stationary satellites.

President, PM hail succesful Insat-3A launch
Indian President Dr A P J Abdul Kalam and Prime Minister Atal Behari Vajpayee and minister of state (space) SB Mookherjee, have congratulated Isro on the successful launch of Insat-3A.

They conveyed their messages to Isro chairman Dr K Kasturirangan at the launch site in Kourou French Guiana, over the phone.

Minister of state (space) SB Mookherjee made a statement regarding Insat-3A's successful launch in both the houses of Parliament yesterday. The Parliament joined him in wishing the Isro team the best in the complex mission that is to be carried out in the next few days from the MCF at Hassan.

As Ariane-5 carried out its mission, ISRO Chairman Dr K Kasturirangan and other top space scientists, including project director RK Rajangam, who were present at Kourou, expressed their joy over the successful launch. Describing the Ariane-5 launch as "a wonderful achievement" in his post-launch comment, a beaming Kasturirangan said it was a "very eventful flight, spectacular and more importantly, technologically precise".

Final geostationary orbit about 36,000 km above equator
In the coming days, orbit raising operations of Insat-3A will be carried out by firing its LAM in stages till the satellite attains its final geostationary orbit, which is about 36,000 km above the equator.

When the satellite reaches near-geostationary orbit, deployment of its solar panels and the two antennas as well as the solar sail 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. The payloads will be subsequently checked out before the commissioning of the satellite.

Insat-3A will be positioned at 93.5 deg East longitude in the geostationary orbit. Other Insat satellite locations are: Insat-2DT at 55 deg East longitude, Insat-2E and Insat-3B at 83 deg East longitude, Insat-3C and Kalpana-1 (formerly it was named Metsat-1) at 74 deg East longitude.

Insat-3A has the main body in the shape of a cuboid of 2.0 x 1.77 x 2.8 m. When its solar panel and solar sail are fully deployed in orbit, the satellite will measure 24.4 m in length. Inast-3A's Sun tracking solar panels generate 3.1 kW of power. Two 70 Ah nickel-hydrogen batteries support full payload operations even during eclipses. Insat-3A, like all its predecessors in the Insat series, is a 3-axis body-stabilised spacecraft using earth sensors, sun sensors, inertial reference unit, momentum/reaction wheels and magnetic torquers. It is equipped with bi-propellant thrusters. The satellite has two deployable antennas and one fixed antenna that carry out various transmit and receive functions.

Insat-3A will provide telecommunication, television broadcasting, meteorology and satellite-aided search and rescue services. The satellite is expected to contine operational services for 12 years.

Insat-3A communication payloads comprise:

*12 C-band transponders, nine of which have expanded coverage providing an Edge-of-Coverage (EoC) Effective Isotropic Radiated Power (EIRP) of 38 dBW and other three having India coverage beam providing an EoC-EIRP of 37 dBW.

*Six upper extended C-band transponders having India beam coverage providing an EoC-EIRP of 37 dBW.

*Six Ku-band transponders having India coverage beam providing an EoC-EIRP of 47.5 dBW and

*A Satellite Aided Search & Rescue (SAS&R) transponder.

The Meteorological Payloads include:
*Very High Resolution Radiometer (VHRR) with 2 km resolution in the visible spectral band and 8 km resolution in infrared and water vapour bands.

*Charge Coupled Device (CCD) camera operating in visible, near infrared and shortwave infrared bands with 1 km resolution.

*Data Relay Transponder (DRT)