The INSAT Master Control Facility (MCF) at Hassan in Karnataka acquired telemetry signal from INSAT - 2E about 8 minutes after its injection into orbit. Immediately thereafter, satellite health checks were carried out and a series of commands issued from MCF so as to orient earth - viewing face of the satellite towards earth. The outermost panel of the stowed solar array on the south side of the satellite was also oriented towards the sun to start generating the electrical power required by the satellite during its transfer orbit phase. The calibration of the gyros on board the satellite has also been carried out.

    INSAT - 2E is being tracked, apart from MCF, Hassan, by INTELSAT Organisation's ground stations at Perth (Australia), Fucino (Italy) and Lake Cowichan (Canada). The satellite will go out of the visibility of MCF, Hassan at about 2:08 pm IST today. It will again come within the radio visibility of MCF at about 1 am tomorrow. The satellite's orbit is being precisely determined by continuous ranging from the participating TTC stations.

    The orbit raising operations on INSAT - 2E will be carried out by firing the 440 Newton liquid apogee motor on board and the satellite in stages till the satellite attains its final Geostationary orbit, about 36,000 km above the equator. The first Apogee Motor Firing (AMF - 1) is planned during the third transfer orbit tomorrow (April 4, 1999) at about 5:50 am IST. The second and third firings (AMF - 2 and AMF - 3) are planned on April 5, 1999 and April 7, 1999 after precise determination of the orbit. Deployment of the solar array and the two antennas are planned to be carried out on April 8, 1999 after the satellite attains near - geosynchronous orbit. The solar sail is planned for deployment on the following day. Subsequently the communication and meteorological payloads will be tested.

    INSAT - 2E will be colocated with INSAT - 1D at 83 deg E Longitude. It may be noted that, at present, INSAT - 2A is located at 74 deg E and INSAT - 2B and INSAT - 2C are colocated at 93.5 deg E longitude while INSAT - 2DT, acquired from ARABSAT, is located at 55 deg E longitudes.

    Indian National Satellite (INSAT) system is a joint venture of Department of Space (DOS), Department of Telecommunications (DOT), India Meteorological Department (IMD), All India Radio (AIR) and Doordarshan (DD). The overall coordination and management of INSAT system rests with Secretary - level INSAT Coordination Committee (ICC). INSAT is one of the largest domestic communications satellite systems in the world today. It provides long distance telecommunications, meteorological earth observation and data relay, direct satellite TV broadcasting to augmented TV receivers, nationwide radio networking, TV programme distribution and rebroadcasting to terrestrial transmitters.

    INSAT - 2E weighing about 2,550 kg at lift-off, is the last of second generation satellites built by ISRO. It is the most advanced satellite built so far in terms of technologies used in the mechanical and electronic hardware and state-of-art payloads. The communication payload is designed with 17 C-band transponders, out of which five channels operate in lower extended C-band and 12 channels operate in normal C-band. Ten of the channels, including five lower extended C-band channels operate through a shaped zonal beam, whose coverage includes India, China, Middle East and major parts of South East Asia. The remaining channels operate through a shaped wide beam, whose coverage extends from Central Europe to Australia and includes China and southern parts of erstwhile USSR.

    Under an agreement between the Department of Space and INTELSAT, eleven 36 MHz equivalent C-band capacity on board INSAT - 2E will be leased to INTELSAT for a period of 10 years.

    The meteorological payload on board INSAT - 2E includes an improved version of Very High Resolution Radiometer (VHRR) and a high resolution Charge Coupled Device (CCD) camera. The VHRR payload operates in three spectral bands, namely, visible, thermal infrared and water-vapour bands. This payload will be used for imaging cloud cover including cyclone formation and its movement, estimation of water vapour content in the clouds and rain forecast. The CCD camera also operates in three spectral bands, namely, visible, near infrared and short-wave infrared bands. The data from this payload supplements VHRR data to assist in cyclone analysis, local severe storm monitoring, hcavy-rainfall forecast and estimation, snow detection and long term climatic studies.

    INSAT - 2E is configured with single-sided solar array consisting of four panels. This configuration is chosen to avoid any heat load on the IR detector cooler of VHRR, mounted on the spacecraft north side. To counteract the torque generated due to solar pressure on the array, a solar sail mounted on a boom is introduced on the northern side of the satellite. Inclusion of the solar flap at the tip of solar array helps to overcome seasonal variation in the solar radiation pressure torque. The Attitude and Orbit Control System (AOCS) provides three axis body stabilisation with a momentum biased system by making use of momentum wheels, earth and sun sensors, magnetic torquer and reaction control thrusters.

    The power system of INSAT - 2E provides regulated dual power bus. Critical subsystems can be connected to any of the bus by ground command. The solar panels use Ga-As/Ge (Gallium-Arsenic/Germanium) cells and generate a net power of about 2,240 Watts. Two 60 Ah Nickel Hydrogen batteries provide eclipse period power support for full payload operations.

    INSAT - 2E uses many state-of -the art technology elements such as embedded heat pipe panels for efficient thermal control, high efficiency Ga-As/Ge solar cells in the solar array for obtaining a high power to area ratio, high capacity nickel-hydrogen batteries for full payload support during eclipses, ASICs (Application Specific Integrated Cricuits) and HMCs (Hybrid Micro Circuits) to reduce volume and mass of electronics packages. The communication payloads use shaped beam dual-grid antenna for the first time, which provides land mass coverage. Again, for the first time, apart from Charge Coupled Device Camera (CCD), a water vapourchannel has been introduced in the VHRR instrument of this satellite. CCD camera provides a resolution of 1 km from the geostationary altitude. The mechanism used for the operation of the solar flaps employs shape memory alloy, a new technique. INSAT - 2E weighs about 2,550 kg at lift-off including 1404 kg of propellants required for orbit raising and in-orbit control for the planned mission life of 12 Years.

    ISRO Satellite Centre, Bangalore, as the lead centre for INSAT -2 project, was responsible for the design, development and integration and testing of INSAT -2E. The communication and meteorological payloads were developed by Space Applications Centre, Ahmedabad. The Liquid Propulsion Systems Centre of ISRO developed the Liquid Apogee Motor and reaction control systems. The Vikram Sarabhai Space Centre supplied the various composite element subsystems such as CFRP antenna and the pyro system. ISRO Inertial Systems Unit, Thiruvananthapuram, was responsible for the design and development of the gyros, momentum/reaction wheels and the solar array drive and power transfer mechanisms. MCF, Hassan is responsible for the on - orbit operations of the satellite.

    Several industries and institutions both in public and private sector, have contributed for the realisation of the satellite and several major test facilities.