The GSAT 7B and India’s Other Military Satellites : Daily Current Affairs

Relevance: GS-3 : Achievements of Indians in science & technology; indigenization of technology and developing new technology.

Key Phrases: GSAT-7B, Aatmanirbhar Bharat’, geosynchronous transfer orbit, Indian Angry Bird, ultra-high frequency, ku-band, c-band,AoN, perigee, Apogee.

Why in News?

The Indian Army is set to get a long-awaited dedicated military communication satellite as the Defence Acquisition Council approved Acceptance of Necessity (AoN) for Capital Acquisition proposals of Armed Forces.
Defence Minister gave his nod to the Acceptance of Necessity for GSAT-7B Satellite that will enhance operational preparedness of the Armed Forces and boost its communication capabilities.

What are the GSAT 7 series satellites?

GSAT 7 satellites are advanced satellites developed by the Indian Space Research Organisation (ISRO) to meet the communication needs of the defence services.
The GSAT 7 satellite was launched in August 2013 from an Ariane 5 ECA rocket from Kourou in French Guiana.
It is a 2,650 kg satellite which has a footprint of nearly 2,000 nautical miles in the Indian Ocean region.
This satellite is mainly used by the Indian Navy for its communication needs.
The GSAT 7 provides a gamut of services for military communication needs, which includes low bit voice rate to high bit rate data facilities, including multi-band communications.
Named Rukmini, the satellite carries payloads in (Ultra High Frequency)UHF, C-band and Ku-band, and helps the Navy to have a secure, real time communication link between its land establishments, surface ships, submarines and aircraft.
The satellite was injected into a geosynchronous transfer orbit (GTO) of 249 km perigee (nearest point to earth), 35,929 km apogee (farthest point to earth) and an inclination of 3.5 degree with respect to the equator.

Note:-

Acceptance of Necessity(AoN) : AoN is the first step of the long-drawn defence procurement process which culminates in placing orders for the equipment needed.
C-band : C-band refers to the portion of the electromagnetic spectrum allotted for satellite transmissions in the 4GHz to 8GHz frequency range. C-band satellite antennas are used frequently in areas of the world where signals can become degraded due to heavy rain or other intense climate-related conditions.
Ku-band : The Ku-band frequency spectrum (12-18GHz) for satellite communication is commonly used for maritime VSAT services.
Geosynchronous Transfer Orbit : A geosynchronous transfer orbit or geostationary transfer orbit (GTO) is a type of geocentric orbit. Satellites that are destined for geosynchronous (GSO) or geostationary orbit (GEO) are (almost) always put into a GTO as an intermediate step for reaching their final orbit.

What will be the Role of the GSAT 7B Satellite?

Fulfils Communication Needs:
- The GSAT 7B will primarily fulfill the communication needs of the Army. Currently, the Army is using 30 per cent of the communication capabilities of the GSAT 7A satellite, which has been designed for the Indian Air Force (IAF).
Enhance Surveillance:
- The GSAT 7B will also help the Army enhance its surveillance in border areas.
Benefit the UAVs:
- GSAT-7B when launched, will benefit the Unmanned Aerial Vehicles(UAVs) in the force’s inventory by ensuring they have an enhanced flying range in line with their original specification, since this satellite can provide secure, encrypted communication to them .
Impetus to Aatmanirbhar Bharat:
- As an impetus to ‘Aatmanirbhar Bharat’, all of these proposals have been approved under the ‘buy (Indian IDDM)’ category with a focus on indigenous design & development and manufacturing in India.

Role of the GSAT- 7A satellite, which is already operational

The GSAT-7A was launched in 2018 from the Satish Dhawan Space Centre in Sriharikota, and has gone a long way in boosting the connectivity between the ground radar stations, airbases and the airborne early warning and control aircraft (AEW&C) of the IAF.
It also helps in satellite controlled operations of unmanned aerial vehicles (UAVs) which gives a great deal of reliability to the operations as compared to ground controlled operations.
This satellite has 10 channels in Ku band with switchable frequency for mobile users, one fixed Gregorian or parabolic antenna, and four steerable antennae.

Some other kinds of military satellites of India

An Electromagnetic Intelligence Gathering Satellite (EMISAT), developed by ISRO, was launched in April 2020 through a Polar Satellite Launch Vehicle (PSLV-C45).
It has an Electronic Intelligence (ELINT) package called Kautilya, which allows the interception of ground-based radar and also carries out electronic surveillance across India.
The ELINT package provides the capability in direction-finding of radar and fixing their locations.
It is placed in a 748-km orbit, and is said to be based on the Israeli satellite system.
This satellite circles the globe pole-to-pole, and is helpful in gathering information from radars of countries that have borders with India.
India also has a RISAT 2BR1 synthetic aperture radar imaging satellite, which was launched in December 2019 from Sriharikota. It has the capability to operate in different modes including very high resolution imaging modes of 1×0.5 metre resolution and 0.5×0.3 m resolution with a swath of 5-10 km.

Future Projects

A GSAT 7C satellite is on the cards for the IAF, and a proposal to this effect was cleared by the DAC in 2021.
This satellite would facilitate real time communication with IAF’s software defined radio communication sets. It will increase the capability of the IAF to communicate beyond the line of sight in a secure mode.

Conclusion

It is a positive move by government to accord the AoN to the Army for having its exclusive communication satellite GSAT-7B but India still has a long way to go in developing its military capabilities in the space domain, especially at a time when china is investing heavily towards augmenting its satellite programmes.

Sources: India-Today Indian-Express

Mains Question:

Q. What is GSAT-7B satellite that will boost Indian Army communication capabilities? Briefly discuss about India’s various military satellites. (Words 250).