GSAT-7 or INSAT-4F is a multi-band military communications satellite developed by the

Indian Space Research Organisation The Indian Space Research Organisation (ISRO; ) is the national space agency of India, headquartered in Bengaluru. It operates under the Department of Space (DOS) which is directly overseen by the Prime Minister of India, while the Chairman o ...

. The

Indian Navy The Indian Navy is the maritime branch of the Indian Armed Forces. The President of India is the Supreme Commander of the Indian Navy. The Chief of Naval Staff, a four-star admiral, commands the navy. As a blue-water navy, it operates si ...

is the user of the multi-band communication spacecraft, which has been operational since September 2013. According to defense experts, the satellite will enable the navy to extend its blue water capabilities and stop relying on foreign satellites like Inmarsat, which provide communication services to its ships.

Satellite

GSAT-7, the multi-band communication satellite named ''Rukmini'' carries the payloads in

UHF Ultra high frequency (UHF) is the ITU designation for radio frequencies in the range between 300 megahertz (MHz) and 3 gigahertz (GHz), also known as the decimetre band as the wavelengths range from one meter to one tenth of a meter (on ...

, C band and . It is the first dedicated military communication satellite (unlike earlier dual use satellites) built by ISRO that will provide services to the Indian Armed Forces with the main user being the Indian Navy. Its procured launch cost has been put at ₹480

crore A crore (; abbreviated cr) denotes ten million (10,000,000 or 107 in scientific notation) and is equal to 100 lakh in the Indian numbering system. It is written as 1,00,00,000 with the local 2,2,3 style of digit group separators (one lakh is eq ...

, with the satellite costing ₹185 crore. Cost of whole project per Memorandum of Understanding with ISRO was ₹950 crores. The multiple-band spacecraft will be used exclusively by the Navy to shore up secure, real-time communications among its warships, submarines, aircraft and land systems. GSAT-7/ INSAT-4F is said to significantly improve the country's naval operations around the world. GSAT 7 satellite carrying payloads operating in UHF, S, C and Ku bands, had a lift-off mass of and is based on ISRO's class satellite bus I-2K with some new technological elements, including the antennae. After a flight of almost 34 minutes, the satellite was injected into a geosynchronous transfer orbit (GTO) of

perigee An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any el ...

apogee An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any el ...

and an inclination of 3.5 degree with respect to the

equator The equator is a circle of latitude, about in circumference, that divides Earth into the Northern and Southern hemispheres. It is an imaginary line located at 0 degrees latitude, halfway between the North and South poles. The term can also ...

. ISRO launched a second satellite, GSAT-7A for

Indian Air Force The Indian Air Force (IAF) is the air force, air arm of the Indian Armed Forces. Its complement of personnel and aircraft assets ranks third amongst the air forces of the world. Its primary mission is to secure Indian airspace and to conduct ...

on 19 December 2018 on its

Geosynchronous Satellite Launch Vehicle Geosynchronous Satellite Launch Vehicle (GSLV) is an expendable launch system operated by the Indian Space Research Organisation (ISRO). GSLV was used in fourteen launches from 2001 to 2021. Even though GSLV Mark III shares the name, it is ...

(GSLV-F11).

Launch

The satellite was launched early on 30 August 2013 atop an

Ariane 5 ECA Ariane 5 is a European heavy-lift space launch vehicle developed and operated by Arianespace for the European Space Agency (ESA). It is launched from the Centre Spatial Guyanais (CSG) in French Guiana. It has been used to deliver payloads into ...

rocket from Kourou,

French Guiana French Guiana ( or ; french: link=no, Guyane ; gcr, label= French Guianese Creole, Lagwiyann ) is an overseas department/region and single territorial collectivity of France on the northern Atlantic coast of South America in the Guianas ...

. India's first dedicated military satellite was put into a geosynchronous orbit, about above Earth, five days after it was launched after three orbit-raising manoeuvres from ISRO's Master Control Facility at Hassan in

Karnataka Karnataka (; ISO 15919, ISO: , , also known as Karunāḍu) is a States and union territories of India, state in the southwestern region of India. It was Unification of Karnataka, formed on 1 November 1956, with the passage of the States Reor ...

. The 2.5-tonne spacecraft's antennae, including the ultra high frequency Helix antenna were deployed before it was stabilised on its three-axis in the orbit. All of the on-board transponders were switched on successfully on September 18, 2013

Capability

Rukmini will provide networking capabilities to various Indian Naval assets. During Theater-level Readiness and Operational Exercise (Tropex) in the

Bay of Bengal The Bay of Bengal is the northeastern part of the Indian Ocean, bounded on the west and northwest by India, on the north by Bangladesh, and on the east by Myanmar and the Andaman and Nicobar Islands of India. Its southern limit is a line bet ...

in 2014, Rukmini was able to network about 60 ships and 75 aircraft seamlessly. Rukmini has a nearly 2,000 nautical mile 'footprint' over the Indian Ocean Region.

Replacement

The

placed an order for

GSAT-7R GSAT-7R is a planned Indian military communication satellite for the Indian Navy to replace GSAT-7. The satellite is projected to cost ₹1,589 crores (US$225.5 million). It is expected to be launched by 2023. See also * GSAT-7A * GSAT * I ...

on June 11, 2019. GSAT-7R is expected to eventually replace GSAT-7.

References

External links

ISRO GSAT-7
* {{Orbital launches in 2013 GSAT satellites INSAT satellites Satellites orbiting Earth Spacecraft launched in 2013 2013 in India