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 India's national List of government space agencies, space agency, headquartered in Bengaluru, Karnataka. It serves as the principal research and development arm of the Department of Space (DoS), ...

. The

Indian Navy The Indian Navy (IN) (ISO 15919, ISO: ) is the Navy, maritime and Amphibious warfare, amphibious branch of the Indian Armed Forces. The President of India is the Supreme Commander of the Indian Navy. The Chief of the Naval Staff (India), Chief ...

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 Inmarsat is a British communications satellite, satellite telecommunications company, offering global mobile services. It provides telephone and data services to users worldwide, via portable or mobile terminals which communicate with groun ...

, 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 ...

, 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 The Indian Armed Forces are the armed forces, military forces of the India, Republic of India. It consists of three professional uniformed services: the Indian Army, the Indian Navy, and the Indian Air Force.—— Additionally, the Indian Ar ...

with the main user being the Indian Navy. Its procured launch cost has been put at ₹480

crore Crore (; abbreviated cr) denotes the quantity ten million (107) and is equal to 100 lakh in the Indian numbering system. In many international contexts, the decimal quantity is formatted as 10,000,000, but when used in the context of the India ...

, 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. The line of apsides (also called apse line, or major axis of the orbit) is the line connecting the two extreme values. Apsides perta ...

apogee An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. The line of apsides (also called apse line, or major axis of the orbit) is the line connecting the two extreme values. Apsides perta ...

and an inclination of 3.5 degree with respect to the

equator The equator is the circle of latitude that divides Earth into the Northern Hemisphere, Northern and Southern Hemisphere, Southern Hemispheres of Earth, hemispheres. It is an imaginary line located at 0 degrees latitude, about in circumferen ...

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

Indian Air Force The Indian Air Force (IAF) (ISO 15919, ISO: ) is the air force, air arm of the Indian Armed Forces. Its primary mission is to secure Indian airspace and to conduct aerial warfare during armed conflicts. It was officially established on 8 Octob ...

on 19 December 2018 on its Geosynchronous Satellite Launch Vehicle (GSLV-F11).

Launch

The satellite was launched early on 30 August 2013 atop an

Ariane 5 ECA Ariane 5 is a retired European Heavy-lift launch vehicle, heavy-lift space launch vehicle operated by Arianespace for the European Space Agency (ESA). It was launched from the Guiana Space Centre (CSG) in French Guiana. It was used to deliver p ...

rocket from Kourou,

French Guiana French Guiana, or Guyane in French, is an Overseas departments and regions of France, overseas department and region of France located on the northern coast of South America in the Guianas and the West Indies. Bordered by Suriname to the west ...

. 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 The Master Control Facility (MCF) is a facility set up by the Indian Space Research Organisation (ISRO) in the city of Hassan in the Indian state of Karnataka. Established in 1982, this facility is responsible for monitoring and controlling ...

at Hassan in

Karnataka Karnataka ( ) is a States and union territories of India, state in the southwestern region of India. It was Unification of Karnataka, formed as Mysore State on 1 November 1956, with the passage of the States Reorganisation Act, 1956, States Re ...

. 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. Geographically it is positioned between the Indian subcontinent and the Mainland Southeast Asia, Indochinese peninsula, located below the Bengal region. Many South Asian and Southe ...

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

References

External links