{{Short description|Series of multipurpose geo-stationary satellites launched by ISRO}} {{distinguish|Indian Regional Navigational Satellite System}} {{Use Indian English|date=December 2019}} {{Use dmy dates|date=December 2021}}
{{Infobox spacecraft class | name = INSAT | image = Insat-1B.jpg | caption = INSAT-1B | manufacturer = ISRO | country = India | bus = | applications = Communications and Meteorology | orbits = Geostationary orbit | operator = INSAT | lifetime = | derivedfrom = | derivatives = <!--spacecraft classes derived from it (not using it)--> | Preceded = <!--spacecraft class preceding--> | Succeeded = <!--spacecraft class succeeding-->
<!--Production--> | status = In service | built = 24 | orders = 0 | launched = 24 | operational = 9 | retired = 12 | failed = 1 | lost = 2 | first = INSAT-1A, 10 April 1982 | last = INSAT-3DS, 17 February 2024 }}
The '''Indian National Satellite System''' or '''INSAT''', is a series of multipurpose geostationary satellites launched by ISRO to satisfy telecommunications, broadcasting, meteorology, and search and rescue operations. Commissioned in 1983, INSAT is the largest domestic communication system in the Indo-Pacific Region and laid the foundation for India's self-reliant space-based communication infrastructure. It is a joint venture of the Department of Space, Department of Telecommunications, India Meteorological Department, All India Radio and Doordarshan. The overall coordination and management of INSAT system rests with the Secretary-level INSAT Coordination Committee.
INSAT satellites provide transponders in various bands to serve the television and communication needs of India. Some of the satellites also have the Very High Resolution Radiometer (VHRR), CCD cameras for meteorological imaging. The satellites also incorporate transponder(s) for receiving distress alert signals for search and rescue missions in the South Asian and Indian Ocean Region, as ISRO is a member of the Cospas-Sarsat program.
==INSAT system== thumb|right|250px|INSAT-1B satellite: Broadcasting sector in India is highly dependent on INSAT system. The Indian National Satellite (INSAT) system was commissioned with the launch of INSAT-1B in August 1983 (INSAT-1A, the first satellite was launched in April 1982 but could not fulfil the mission). INSAT system ushered in a revolution in India's television and radio broadcasting, telecommunications and meteorological sectors. It enabled the rapid expansion of TV and modern telecommunication facilities to even the remote areas and off-shore islands. Together, the system provides transponders in C, Extended C and K<sub>u</sub> bands for a variety of communication services. Some of the INSATs also carry instruments for meteorological observation and data relay for providing meteorological services. KALPANA-1 is an exclusive meteorological satellite. The satellites are monitored and controlled by Master Control Facilities that exist in Hassan and Bhopal.
=== INSAT-1 series === The first generation of INSAT satellites, developed with NASA assistance, included INSAT-1A, 1B, 1C, and 1D, with all of them being launched in the 1980s. Their success established India's capability to operate a national communications and weather-monitoring satellite fleet. 1B, launched in 1983, became the first fully operational Indian GEO communications satellite.
=== INSAT-2 series === The INSAT-2 series during the 1990s, marked the shift to fully indigenous satellite design. Models included INSAT-2A, 2B, SC, 2D, and 2E, each offering expanded transponder capacity, improved meteorological imaging and enhanced reliability.
=== INSAT-3 series === Launched between 2000 and 2003, the INSAT-3 series introduced larger satellites with advanced payloads. 3B was for business communication, 3C for national telecommunication backbone, 3A and 3D for meteorology and disaster warning, and 3E for {{sic|?|broadacting}} and data relay.
=== INSAT-4 series === The INSAT-4 generation launched between 2005 and 2010 focused on high-power K<sub>u</sub>-band DTH broadcasting. 4A was India's first dedicated DTH satellite, 4B and 4CR was for communication and replacement missions, and 4E (also known as GSAT-6) had a large S-band antenna for mobile communications. INSAT-4 satellites were eventually supplemented by the newer GSAT series.
=== Transition into GSAT === {{main|GSAT}} Many communication satellites which were originally conceived under the INSAT umbrella were reclassified as GSAT as ISRO shifted to newer satellite bus platforms of I-2K and I-3K. INSAT continues to focus mainly on meteorology and disaster management, while GSAT handles broadband, telecom, and strategic communication.
== List of INSAT satellites == The following is a list of launched INSAT satellites. {{sticky header}}{{Sort under}}{{Table alignment}} {| class="wikitable sortable sticky-header-multi sort-under col9center col10center" style="font-size: 85%; text-align:left;" |+ Launched INSAT satellites |- ! scope="col" rowspan=2 | INSAT series ! scope="col" rowspan=2 | GSAT Series ! scope="col" rowspan=2 | Other name(s) ! scope="col" rowspan=2 | COSPAR ID ! scope="col" rowspan=2 | Launch date and time,<br/>UTC ! scope="col" rowspan=2 | Launch vehicle ! scope="col" rowspan=2 | Lift-off mass ! scope="colgroup" colspan=2 | Orbital parameters ! scope="col" rowspan=2 | Outcome ! scope="col" rowspan=2 | Purpose |- ! scope="col" | Longitude ! scope="col" | Inclination |- ! rowspan=2 scope="row" | INSAT-1A ! rowspan=2 colspan=2 scope="row" {{n/a}} | 1982-031A | {{dts|10 April 1982}}, 06:47:00 | {{flagicon|USA}} Delta 3910 / PAM-D | {{convert|1152|kg|lb|abbr=on}} | 74° East | 14.59° | {{Partial|Partial success}} | Communication |- | colspan=9 | First Satellite in INSAT Series and First Satellite of INSAT-1 Series. Built by Ford Aerospace, operated for only five months out of seven years planned. Abandoned on 6 September 1982 after a series of failures. |- ! rowspan=2 scope="row" | INSAT-1B ! rowspan=2 colspan=2 scope="row" {{n/a}} | 1983-089B | {{dts|30 August 1983}}, 06:32:00 | {{flagicon|USA}} Space Shuttle ''Challenger'' STS-8 / PAM-D | {{convert|1152|kg|lb|abbr=on}} | 93° East (1992-93){{efn|74° East (1983-92)}} | 14.69° | {{Success|Successful}} | Communication |- | colspan=9 | First successful INSAT satellite. At the end of its seven-year design life it was replaced by the newly launched INSAT-1D, dropping to backup status. Decommissioned in August 1993. |- ! rowspan=2 scope="row" | INSAT-1C ! rowspan=2 colspan=2 scope="row" {{n/a}} | 1988-063A | {{dts|21 July 1988}}, 06:32:00 | {{flagicon|FRA}} Ariane 3 | {{convert|1190|kg|lb|abbr=on}} | 93.5° East | 11.6° | {{Success|Successful}} | Communication and meteorology |- | colspan=9 | Decommissioned in 2001 after thirteen years of service. |- ! rowspan=2 scope="row" | INSAT-1D ! rowspan=2 colspan=2 scope="row" {{n/a}} | 1988-063A | {{dts|9 July 1992}}, 05:52:00 | {{flagicon|USA}} Delta 4000 4925-8 | {{convert|1190|kg|lb|abbr=on}} | 83° East | 14.30° | {{Success|Successful}} | Telecom |- | colspan=9 | Last satellite of INSAT-1 series. Aided in setting up national computer networks. Decommissioned on 14 May 2002. |- ! rowspan=2 scope="row" | INSAT-2A ! rowspan=2 colspan=2 scope="row" {{n/a}} | 1992-041A | {{dts|9 July 1992}}, 22:42:00 | {{flagicon|FRA}} Ariane 4 44L V-51/423 | {{convert|1906|kg|lb|abbr=on}} | 74° East | 14.5° | {{Success|Successful}} | Meteorology and Search and rescue |- | colspan=9 | INSAT-2A has an advanced power amplifiers for catering communication terminals and was the first series-2 satellite to replace the INSAT-1. |- ! rowspan=2 scope="row" | INSAT-2B ! rowspan=2 colspan=2 scope="row" {{n/a}} | 1993-048B | {{dts|22 July 1993}}, 22:58:00 | {{flagicon|FRA}} Ariane 4 44L V-58/429 | {{convert|1906|kg|lb|abbr=on}} | 93.5° East | 14.4° | {{Success|Successful}} | Multipurpose |- | colspan=9 | Primarily for telecommunication and meteorological observations, also carried a search and rescue transponder. Decommissioned on 1 July 2004. |- ! rowspan=2 scope="row" | INSAT-2C ! rowspan=2 colspan=2 scope="row" {{n/a}} | 1995-067B | {{dts|6 December 1995}}, 23:23:00 | {{flagicon|FRA}} Ariane 4 44L V-81/453 | {{convert|2106|kg|lb|abbr=on}} | 93.5° East | 14.2° | {{Success|Successful}} | Communication |- | colspan=9 | It had capabilities of business communication, mobile satellite service and could make television outreach beyond boundaries of India. In January 2013, its communication C-band transponder collapsed. It also improved communication facilities in Northeast India and Andaman and Nicobar Islands. |- ! rowspan=2 scope="row" | INSAT-2D ! rowspan=2 colspan=2 scope="row" {{n/a}} | 1997-027B | {{dts|4 June 1997}}, 23:23:00 | {{flagicon|FRA}} Ariane 4 44L V-97/468 | {{convert|2079|kg|lb|abbr=on}} | 93.5° East | 12.8° | {{Partial|Partial success}} | Communication |- | colspan=9 | Became inoperable just four months later on 4 October 1997, due to a power bus anomaly and associated problems, most likely a short circuit.<ref>{{Cite web |title=INSAT-2D |url=https://www.isro.gov.in/INSAT_2D.html?timeline=timeline#:~:text=INSAT-2D%20Home%20/%20Activities%20/,Orbit |access-date=2025-11-24 |website=www.isro.gov.in}}</ref> |- ! rowspan=2 scope="row" | INSAT-2DT ! rowspan=2 scope="row" {{n/a}} ! rowspan=2 scope="row" | {{flagicon|KSA}} Arabsat-1C (formerly) | 1992-010 | {{dts|26 February 1992}}, 23:58:10 | {{flagicon|FRA}} Ariane 4 44L V-49/421 | {{convert|1360|kg|lb|abbr=on}} | 82.5° East | 14.2° | {{Success|Successful}} | Communication |- | colspan=9 | In November 1997, Arabsat-1C was sold to India as INSAT-2DT.<ref name="TSE-1C">{{cite web |url=http://www.tbs-satellite.com/tse/online/sat_arabsat_1c.html |title=Arabsat 1C |publisher=TSE |access-date=2009-07-05}}</ref> Decommissioned in October 2004. |- ! rowspan=2 scope="row" | INSAT-2E ! rowspan=2 scope="row" {{n/a}} ! rowspan=2 scope="row" | APR-1 | 1999-016A | {{dts|2 April 1999}}, 22:03:00 | {{flagicon|FRA}} Ariane 4 42P V-117/486 | {{convert|2550|kg|lb|abbr=on}} | 83° East | 11° | {{Operational}} | Communication and weather |- | colspan=9 | INSAT-2E is using ultra-light Magnesium-lithium alloys developed by DMRL. It also carries two meteorological instruments; the Very High Resolution Radiometer (VHRR), and a CCD camera capable of returning images with a resolution of one kilometre. |- ! rowspan=2 scope="row" | INSAT-3A ! rowspan=2 colspan=2 scope="row" {{n/a}} | 2003-013A | {{dts|9 April 2003}}, 22:52:00 | {{flagicon|FRA}} Ariane 5 42P V-117/486 | {{convert|2950|kg|lb|abbr=on}} | 93.5° East | 8.3° | {{Operational}} | Multipurpose |- | colspan=9 | Third satellite launched in INSAT-3 series after INSAT-3B & INSAT-3C. |- ! rowspan=2 scope="row" | INSAT-3B ! rowspan=2 colspan=2 scope="row" {{n/a}} | 2000-016B | {{dts|21 March 2000}}, 23:28:00 | {{flagicon|FRA}} Ariane 5 G 505 | {{convert|5800|kg|lb|abbr=on}} | 83° East | 10.4° | {{success|Successful}} | Communication |- | colspan=9 | First Geostationary satellite of India. |- ! rowspan=2 scope="row" | INSAT-3C ! rowspan=2 colspan=2 scope="row" {{n/a}} | 2002-002A | {{dts|23 January 2002}}, 23:46:57 | {{flagicon|FRA}} Ariane 4 42L-3 4108 | {{convert|5800|kg|lb|abbr=on}} | 74° East | 7.9° | {{Operational}} | Multipurpose |- | colspan=9 | Provides voice, video and digital data services to India and neighboring countries. |- ! rowspan=2 scope="row" | INSAT-3D ! rowspan=2 colspan=2 scope="row" {{n/a}} | 2013-038B | {{dts|25 July 2013}}, 19:54:07 | {{flagicon|FRA}} Ariane 5 ECA 569 | {{convert|2061|kg|lb|abbr=on}} | 82° East | 1.4° | {{Operational}} | Meteorology |- | colspan=9 | The satellite had many new technology elements like star sensor, micro stepping Solar Array Drive Assembly (SADA) to reduce the spacecraft disturbances and Bus Management Unit (BMU) for control and telecom and telemetry function. |- ! rowspan=2 scope="row" | INSAT-3DR ! rowspan=2 colspan=2 scope="row" {{n/a}} | 2016-054A | {{dts|8 September 2016}}, 11:20:00 | {{flagicon|IND}} GSLV MkII F09 | {{convert|2061|kg|lb|abbr=on}} | 74° East | 0.1° | {{Operational}} | Meteorology |- | colspan=9 | Uses a 6-channel imager and a 19-channel sounder, as well as search and rescue information and message relay for terrestrial data collection platforms. |- ! rowspan=2 scope="row" | INSAT-3DS ! rowspan=2 colspan=2 scope="row" {{n/a}} | 2024-033A | {{dts|17 February 2024}}, 12:05:00 | {{flagicon|IND}} GSLV MkII F14 | {{convert|2275|kg|lb|abbr=on}} | 74° East | 0.0° | {{Operational}} | Meteorology |- | colspan=9 | Follow on of INSAT-3DR mission. |- ! rowspan=2 scope="row" | INSAT-3E ! rowspan=2 colspan=2 scope="row" {{n/a}} | 2003-047E | {{dts|27 September 2003}}, 23:14:46 | {{flagicon|FRA}} Ariane 5G V162 | {{convert|2775|kg|lb|abbr=on}} | 55° East | 9.2° | {{Success|Successful}} | Communication |- | colspan=9 | Ran out of oxidizer after seven years of operation, moved to Graveyard orbit in April 2014.<ref name="thehindu.com">{{Cite news|url=https://www.thehindu.com/sci-tech/technology/after-10-years-in-orbit-insat3e-expires/article5859974.ece|title=After 10 years in orbit, INSAT-3E expires|newspaper=The Hindu|date=2 April 2014|last1=S|first1=Madhumathi D.}}</ref> |- ! rowspan=2 scope="row" | INSAT-4A ! rowspan=2 colspan=2 scope="row" {{n/a}} | 2005-049A | {{dts|21 December 2005}}, 22:33:00 | {{flagicon|FRA}} Ariane 5GS 525 | {{convert|1386|kg|lb|abbr=on}} | 83° East | 5.9° | {{Success|Successful}} | Telecom |- | colspan=9 | At the time of launch, it was the heaviest satellite India had built. Decommissioned on 21 October 2019. |- ! rowspan=2 scope="row" | INSAT-4B ! rowspan=2 colspan=2 scope="row" {{n/a}} | 2007-007A | {{dts|11 March 2007}}, 22:03:00 | {{flagicon|FRA}} Ariane 5ECA 535 | {{convert|1335|kg|lb|abbr=on}} | 93.48° East | 5.6° | {{Success|Successful}} | Communication |- | colspan=9 | Suffered a disruption in power supply from one of the two solar panels, rendering half of its transponder capacity useless.<ref>{{Cite book|title=My Odyssey: Memoirs of the Man behind the Mangalyaan Mission|last=Radhakrishnan|first=Koppillil|publisher=Penguin UK|year=2016|isbn=978-9385990380|pages=190}}</ref> Decommissioned on 24 January 2022. |- ! rowspan=2 scope="row" | INSAT-4C ! rowspan=2 colspan=2 scope="row" {{n/a}} | {{n/a}} | {{dts|10 July 2006}}, 12:08:00 | {{flagicon|IND}} GSLV MKI F02 | {{convert|2168|kg|lb|abbr=on}} | colspan=2 {{n/a}} | {{Failure|Launch failure}} | Communication |- | colspan=9 | Both rocket and satellite had to be destroyed over the Bay of Bengal after the rocket's trajectory veered outside permitted limits. |- ! rowspan=2 scope="row" | INSAT-4CR ! rowspan=2 colspan=2 scope="row" {{n/a}} | 2007-037A | {{dts|2 September 2007}}, 12:51:00 | {{flagicon|IND}} GSLV MKI F04 | {{convert|2168|kg|lb|abbr=on}} | 74° East | 6.3° | {{Success|Successful}} | Communication |- | colspan=9 | Due to an error in the guidance subsystem , rocket achieved orbit had lower apogee and inclination higher than expected. Orbit corrected through satellite, eventually the INSAT-4CR was placed in its slot. Decommissioned on 24 November 2020. |- ! rowspan=2 scope="row" | INSAT-4E ! rowspan=2 scope="row" | GSAT-6 ! rowspan=2 scope="row" {{n/a}} | 2015-041A | {{dts|27 August 2015}}, 11:22:00 | {{flagicon|IND}} GSLV MKII D6 | {{convert|2117|kg|lb|abbr=on}} | 83° East | 6.3° | {{Operational}} | Multimedia |- | colspan=9 | Offers a Satellite Digital Multimedia Broadcasting (S-DMB) service across several digital multimedia terminals or consoles which can be used to provide information services to vehicles on the fly and to the mobile phones. |- ! rowspan=2 scope="row" | INSAT-4F ! rowspan=2 scope="row" | GSAT-7 ! rowspan=2 scope="row" {{n/a}} | 2013-044B | {{dts|29 August 2013}}, 20:30:00 | {{flagicon|FRA}} Ariane 5 ECA 570 | {{convert|2117|kg|lb|abbr=on}} | 74° East | 0.1° | {{Operational}} | Military |- | colspan=9 | 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. |- ! rowspan=2 scope="row" | INSAT-4G ! rowspan=2 scope="row" | GSAT-8 ! rowspan=2 scope="row" {{n/a}} | 2011-022A | {{dts|20 May 2011}}, 20:38:00 | {{flagicon|FRA}} Ariane 5 ECA VA202 | {{convert|2117|kg|lb|abbr=on}} | 55° East | 1.6° | {{Operational}} | Communication |- | colspan=9 | First satellite to carry GAGAN payload. |}
== See also == * List of Indian satellites * Indian Remote Sensing Programme (IRSP) * Indian Regional Navigation Satellite System (IRNSS) * GSAT
== Notes == {{notelist}}
== References == {{commons category}} {{Reflist}}
{{INSAT Satellites}} {{Indian spacecraft}} {{Indian space programme}}
Category:ISRO programmes * Category:Communications satellite constellations Category:1983 establishments in India