The Indian Space Research Organization (ISRO) has made significant strides in its space program, one notable achievement being the launch of its heaviest communication satellite to date, the GSAT-11. The GSAT-11 was launched by the European Space Agency’s Ariane-5 Rocket, taking off from Guiana Space Centre situated in French Guiana, South America.
ISRO’s rocket GSLV III carries loads up to four thousand kilograms, thus any payloads heavier than this are launched by the European Space Agency. The GSAT-11 is part of ISRO’s high-throughput communication satellite (HTS) fleet, joining already operative satellites – GSAT-29 and GSAT-19.
GSAT-11: An Innovative Communication Satellite
Classified as an advanced communication satellite, GSAT-11 boasts Ka x Ku-Band Forward Link Transponders and Ku x Ka-band Return Link Transponders. It weighs a massive 5,854 Kg and operates within a Geostationary Orbit. Designed with a mission life of 15 years, GSAT-11 is paving the way in creating robust internet connectivity.
Broadly, GSAT’s role involves providing broadband services across regions of India which are currently untouched by the country’s underground fiber Internet coverage. It enhances internet connectivity through the utilization of spot beam technology, which enables greater capacity and high data rates. In addition, GSAT-11 assists in providing substantial bandwidth coverage to the rural administrations (gram panchayats) supporting e-governance and other platforms.
Spot Beam Technology
A spot beam is a satellite signal with a high concentration, covering only a specific geographical area. The narrower the beam, the greater its power. The satellite reuses beams multiple times for countrywide coverage— an efficient way to provide national coverage.
Understanding Types of Orbits: Polar and Geosynchronous
Satellites travel in two general types of orbits – Polar and Geosynchronous. A polar orbit travels north-south over the poles and takes around 90 minutes for a full rotation, whereas Geosynchronous satellites are launched into orbit in the same direction the Earth is spinning.
Polar Orbit
A sun-synchronous orbit is a specific kind of polar orbit. Satellites travelling in these orbits can virtually see every part of the Earth as it rotates underneath. These satellites are typically at lower altitudes and play vital roles such as monitoring crops, global security, measuring ozone concentrations in the stratosphere.
| Satellite Use | Type of Orbit |
|---|---|
| Crop Monitoring | Polar Orbit |
| Global Security | Polar Orbit |
| Ozone Measurements | Polar Orbit |
Geosynchronous Orbit
Geosynchronous satellites are launched into orbit in the same direction in which the Earth is spinning, can have any inclination and when placed at a specific altitude approximately 36,000km above the Earth’s surface, they match the rotation of the Earth. Geostationary orbits fall in the same category as geosynchronous orbits but with one special quality of being parked over the equator.
For a spacecraft to attain geostationary or geosynchronous earth orbit, it is first launched into a Geosynchronous Transfer Orbit (GTO). From the GTO, the spacecraft uses its engines to alter course towards a geostationary or geosynchronous orbit. This is precisely the process implemented by ISRO with the launch of their GSAT-11 satellite.
