The Indian National Satellite System or INSAT, is a series of multipurpose geostationary satellites launched by the Indian Space Research Organisation (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. 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

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 Ku 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.

List of INSAT Satellite

This is a total list of INSAT satellites with their outcome.

Total List Of INSAT Satellites.
Satellite Longitude Date of launch Launch vehicle Lift-off mass Status Notes
INSAT series GSAT series Known as
INSAT-1A - 74° East 10 April 1982 United States Delta 3910 / PAM-D Decommissioned
(6 September 1982)
First Satellite in INSAT Series and First Satellite of INSAT-1 Series.

74° East (1983-92)
93° East (1992-93)

30 August 1983 United States Space Shuttle / PAM-D Decommissioned
(August 1993)
INSAT-1C - 93.5° East 21 July 1988 European Union Ariane 3 Decommissioned
INSAT-1D - 83° East 9 July 1992 United States Delta 4925 Decommissioned
(14 May 2002)
INSAT-2A - 74° East 22 July 1993 European Union Ariane 44L H10 Decommissioned
(30 May 2002)
First Satellite in INSAT-2 Series.
INSAT-2B - 93.5° East 12 June 1990 European Union Ariane 44L H10+ Decommissioned
(1 July 2004)
INSAT-2C - 93.5° East 6 December 1995 European Union Ariane 44L H10-3 In Service
INSAT-2D - 93.5° East 3 June 1997 European Union Ariane 44L H10-3 Decommissioned
(4 Oct, 1997)
INSAT-2DT - INSAT-2R 31° East

55° East
82.5° East

26 February 1992 European Union Ariane 44L H10 Decommissioned
(October 2004)
INSAT-2E - 83° East 2 April 1999 European Union Ariane 42P H10-3 In Service
INSAT-3A - 93.5° East 9 April 2003 European Union Ariane 5G In Service First Satellite in INSAT-3 Series.
INSAT-3B - 83° East 21 March 2000 European Union Ariane 5G In Service
INSAT-3C - 74° East 23 January 2002 European Union Ariane 42L H10-3 In Service
INSAT-3D - 82° East 25 July 2013 European Union Ariane 5 ECA In Service
INSAT-3DR - 74° East 8 September 2016 India GSLV Mk II In Service
INSAT-3DS - 74° East 17 February 2024 India GSLV Mk II In Service
INSAT-3E - 55° East (2003-2014) 21 December 2003 European Union Ariane 5G Decommissioned
(1 April 2014)
INSAT-4A - 83° East 27 September 2005 European Union Ariane 5GS Decommissioned
(21 October 2019)
First Satellite in INSAT-4 Series.
INSAT-4B - 85.5° East

83° East
111.2° East
93.48° East

11 March 2007 European Union Ariane 5 ECA Decommissioned
(24 January 2022)
INSAT-4C - - 10 July 2006 India GSLV Mk I Failed
INSAT-4CR - 48° East

74° East

2 September 2007 India GSLV Mk I Decommissioned
(24 November 2020)
Replacement Satellite for INSAT-4C.
INSAT-4D GSAT-5 - - India GSLV Mk I Cancelled
INSAT-4E GSAT-6 83° East 27 August 2015 India GSLV Mk II In Service
INSAT-4F GSAT-7 74° East 29 August 2013 European Union Ariane 5 ECA In Service
INSAT-4G GSAT-8 55° East 20 May 2011 European Union Ariane 5 ECA In Service

Satellites in service

Of the 24 satellites launched in the course of the INSAT program, 11 are still in operation.[1]


Main article: INSAT-2E

It is the last of the six five satellites in INSAT-2 series. It carries seventeen C-band and lower extended C-band transponders providing zonal and global coverage with an Effective Isotropic Radiated Power (EIRP) of 36 dBW. It also carries a Very High Resolution Radiometer (VHRR) with imaging capacity in the visible (0.55–0.75 μm), thermal infrared (10.5–12.5 μm) and water vapour (5.7–7.1 μm) channels and provides 2x2 km, 8x8 km ground resolution respectively. In addition to the above two payloads it has with it a Charge Coupled Device (CCD) camera providing 1x1 km ground resolution in the Visible (0.63–0.69 μm), Near Infrared (0.77–0.86 μm) and Shortwave Infrared (1.55–1.70 μm) bands.[2]


Main article: INSAT-3A

The multipurpose satellite, INSAT-3A, was launched by Ariane in April 2003. It is located at 93.5 degree East longitude. The payloads on INSAT-3A are as follows:


Main article: INSAT-3C

Launched in January 2002, INSAT-3C is positioned at 74 degree East longitude. INSAT-3C payloads include 24 Normal C-band transponders providing an EIRP of 37 dBW, six Extended C-band transponders with EIRP of 37 dBW, two S-band transponders to provide BSS services with 42 dBW EIRP and an MSS payload similar to that on INSAT-3B. All the transponders provide coverage over India.[4]


Main article: INSAT-3D

Launched in July 2013, INSAT-3D is positioned at 82 Degree East longitude. INSAT-3D payloads include Imager, Sounder, Data Relay Transponder and Search & Rescue Transponder. All the transponders provide coverage over large part of the Indian Ocean region covering India, Bangladesh, Bhutan, Maldives, Nepal, Seychelles, Sri Lanka and Tanzania for rendering distress alert services.[5]


Main article: INSAT-3DR

INSAT-3DR is a weather satellite meant to provide meteorological services to India using a 6-channel imager and a 19-channel sounder, it was launched on 9 September 2016 by the GSLV Mk II F05,[6] and is a follow-up to INSAT-3D.


Main article: INSAT-3E

Launched in September 2003, INSAT-3E is positioned at 55 degree East longitude and carries 24 Normal C-band transponders provide an edge of coverage EIRP of 37 dBW over India and 12 Extended C-band transponders provide an edge of coverage EIRP of 38 dBW over India.[7] The satellite has been decommissioned and gone out of service from April 2014.[8] GSAT-16 will replace this satellite.


Main article: Kalpana-1

KALPANA-1 is an exclusive meteorological satellite launched by PSLV in September 2002. It carries Very High Resolution Radiometer and DRT payloads to provide meteorological services. It is located at 74 degree East longitude. Its first name was METSAT. It was later renamed as KALPANA-1 to commemorate Kalpana Chawla.

INSAT-4 Series


Main article: INSAT-4A

Launched in December 2005 by the European Ariane launch vehicle, INSAT-4A is positioned at 83 degree East longitude along with INSAT-2E and INSAT-3B. INSAT-A carries 12 Ku band 36 MHz bandwidth transponders employing 140 W TWTAs to provide an EIRP of 52 dBW at the edge of coverage polygon with footprint covering Indian main land and 12 C-band 36 MHz bandwidth transponders provide an EIRP of 39 dBW at the edge of coverage with expanded radiation patterns encompassing Indian geographical boundary, area beyond India in southeast and northwest regions.[9] Tata Sky, a joint venture between the TATA Group and STAR uses INSAT-4A for distributing their DTH service.


Main article: INSAT-4B

It was launched in March 2007 by the European Ariane launch vehicle. Configured with payloads identical to that of INSAT-4A, INSAT-4B carries 12 Ku band and 12 C-band transponders to provide EIRP of 52 dBW and 39 dBW respectively. Two Tx/Rx dual grid offset fed shaped beam reflectors of 2.2 m diameter for Ku band and 2 m diameter for C-band are used. INSAT-4B augments the high power transponder capacity over India in Ku band and over a wider region in C-band. It is co-located with INSAT-3A at 93.5 degree E longitude.[10]

The national space agency Indian Space Research Organisation (ISRO) has allotted nearly seven Ku band transponders to Sun Direct; a DTH service provider from South India, and the other five to Doordarshan's DD Direct Plus. 12 transponders in the C band are for TV, radio and telecommunication purposes.

The satellite was decommissioned on 24 January 2022. The satellite was moved to a disposal orbit, 340 km above geostationary orbit.[11]

China-Stuxnet Connection

American cyber warfare expert Jeffrey Carr, who specialises in investigations of cyber attacks against government, mentioned in his interview with The Times of India, that the reason for this power glitch may have been an infection by the sophisticated Stuxnet worm.[12] He attributed the development of Stuxnet worm most likely to Government of China which had the necessary sophistication to develop the bug and would gain the maximum by failure of Indian satellite. He also pointed out that Stuxnet was discovered just a month before the Indian satellite was hit by the power glitch, the reason for which still remains unknown. ISRO uses the same Siemens software that was targeted by Stuxnet.


Main article: INSAT-4CR

INSAT-4CR was launched on 2 September 2007 by GSLV-F04.[13] It is a replacement satellite of INSAT-4C which was lost when GSLV-F02 failed and had to be destroyed on its course. It carries 12 Ku band 36 MHz bandwidth transponders employing 140 W TWTAs to provide an Effective Isotropic Radiated Power of 51.5 dBW at Edge of Coverage with footprint covering Indian mainland. It also incorporates a Ku band Beacon as an aid to tracking the satellite.

On 8 September 2007 ISRO reported the satellite had reached a near geosynchronous orbit, and would be stabilized in its intended orbital position of 74 degrees E longitude by 15 September.[14] The satellite is designed for a mission life in of ten years. There were reports that the mission life of the satellite had decreased by five years as the thrusters had to burn this much fuel to restore the satellite to its correct orbit. However, the ISRO later refuted this claim dismissing it as false.[15]

GSAT Series

The GSAT satellites are India's indigenously developed communications satellites, used for digital audio, data and video broadcasting for both military and civilian users. As of November 2018, 19 GSAT satellites of ISRO have been launched out of which 15 satellites are currently in service.


Main article: GSAT-2

Launched by the second flight of GSLV in May 2003, GSAT-2 is located at 48 degree East longitude and carries four Normal C-band transponders to provide 36 dBW EIRP with India coverage, two Ku band transponders with 42 dBW EIRP over India and an MSS payload similar to those on INSAT-3B and INSAT-3C.


Main article: GSAT-3

Configured for audio-visual medium employing digital interactive classroom lessons and multimedia content, GSAT-3 (EDUSAT) was launched by a GSLV in September 2004. Its transponders and their ground coverage are specially configured to cater to the educational requirements. The satellite carries a Ku band transponder covering the Indian mainland region with 50 dBW EIRP, five Ku band spot beam transponders for south, west, central, north and north-east regional coverage with 55 dBW EIRP and six Extended C-band transponders with India coverage with 37 dBW EIRP. EDUSAT is positioned at 74 degree East longitude and is collocated with KALPANA-1 and INSAT-3.


Main article: INSAT-4E

GSAT-6 (also called INSAT-4E) is a multimedia communication satellite that 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.


Main article: GSAT-7

GSAT-7 (or INSAT-4F) is a multi-band military communications satellite developed by ISRO. The Indian Navy is the user of the multi-band communication spacecraft, which has been operational since September 2013.


Main article: GSAT-8

GSAT-8 (INSAT-4G), is a high power communication satellite in the INSAT system. Weighing about 3,100 kg at lift-off, GSAT-8 is configured to carry 24 high power transponders Ku band and a two-channel GPS Aided Geo Augmented Navigation (GAGAN) payload operating in L1 and L5 bands.


Main article: GSAT-9

The GSAT-9, also known as the "South Asia Satellite", is a geostationary communications satellite and meteorology satellite operated by the ISRO for the South Asian Association for Regional Cooperation (SAARC) region.[16][17] The satellite was launched on 5 May 2017.


Main article: GSAT-10

GSAT-10 was launched by Ariane-5ECA carrier rocket in 2012. It serves with C and Ku band transponders, and includes a navigation payload to augment GAGAN capacity.


Main article: GSAT-12

GSAT-12 configured to carry 12 Extended C-band transponders to meet the country's growing demand for transponders in a short turn-around-time. The 12 Extended C-band transponders of GSAT-12 will augment the capacity in the INSAT system for various communication services like Tele-education, Telemedicine and for Village Resource Centres (VRC). It weighs about 1,410 kg (3,110 lb) at lift-off.


Main article: GSAT-14

GSAT-14 was launched in January 2014 to replace the GSAT-3 satellite, which was launched in 2004.


Main article: GSAT-15

GSAT-15 is similar to GSAT-10 and is used to augment the capacity of transponders to provide more bandwidth for Direct-to-Home television and VSAT services. It was successfully launched on 10 November 2015 at 21:34:07 UTC aboard an Ariane 5 rocket, along with the ArabSat 6B satellite.[18]


Main article: GSAT-16

GSAT-16 is the 11th Indian communication satellite meant to increase the number of transponders that in turn enhance the satellite based telecommunication, television, VSAT services in India. GSAT-16 was launched on 7 December 2014 from the Guiana Space Centre, French Guiana, by an Ariane 5 rocket.


Main article: GSAT-17

it carries 24 C-band, 2 lower C-band, 12 upper C-band, 2 CxS (C-band up/S-band down), and 1 SxC (S-band up/C-band down) transponders. It additionally carries a dedicated transponder for data relay (DRT) and search-and-rescue (SAR) services.[19] At the time of launch, GSAT-17 was the heaviest satellite built by ISRO.[20] The satellite was launched on 28 June 2017 aboard an Ariane 5 ECA rocket from the Guiana Space Centre in Kourou, French Guiana.


Main article: GSAT-18

GSAT-18 carries 24 C-band, 12 extended C-band, and 12 Ku-band transponders. It was launched on 5 October 2016 aboard an Ariane 5 ECA rocket from the Guiana Space Centre in Kourou, French Guiana.


Main article: GSAT-19

Launched on 5 June 2017, GSAT-19 is a communication satellite testbed for the modular I-6K satellite bus, carrying experimental technologies such as ion thrusters for manoeuvring and stabilisation, active thermal control using thermal radiators, a miniaturised inertial reference unit, indigenously produced lithium-ion batteries, and C-band traveling-wave-tube amplifiers.[21][22][23]


Main article: GSAT-29

The GSAT-29 is a large high-throughput communication satellite that was launched on 14 November 2018 through the second developmental flight of GSLV Mark III,[24] that placed the 3,423 kg (7,546 lb) satellite into its planned geosynchronous transfer orbit (GTO) over the equator.[25] Apart from its main communication payload in Ka/Ku bands, GSAT-29 hosts few experimental payloads to mature their technology for use in future spacecraft.[26]


Commercial Communications satellite

Indian Communication Satellites Launch Log

Serial No. Satellite Date of Launch Launch Vehicle Status
1 INSAT-1A 10 April 1982 Delta Failed in orbit
2 INSAT-1B 30 August 1983 Shuttle PAM-D Mission Completed
3 INSAT-1C 22 July 1988 Ariane-3 Partial failure in orbit
4 INSAT-1D 12 June 1990 Delta Mission Completed
5 INSAT-2A 10 July 1992 Ariane-4 Mission Completed
6 INSAT-2B 23 July 1993 Ariane-4 Mission Completed
7 INSAT-2C 7 December 1995 Ariane-4 Mission Completed
8 INSAT-2D 4 June 1997 Ariane-4 Failed in Orbit
9 INSAT-2E 3 April 1999 Ariane-4 Mission Completed
10 INSAT-3B 22 March 2020 Ariane-5 Mission Completed
11 GSAT-1 18 April 2001 GSLV Mission Completed
12 INSAT-3C 24 January 2002 Ariane-5 Mission Completed
13 KALPANA-1 12 September 2002 PSLV Mission Completed
14 INSAT-3A 10 April 2003 Ariane-5 Mission Completed
15 GSAT-2 8 May 2003 GSLV
16 INSAT-3E 28 September 2003 Ariane-5
17 EDUSAT 20 September 2004 GSLV Mission Completed
18 HAMSAT 5 May 2005 PSLV
19 INSAT-4A 22 December 2005 Ariane-5
20 INSAT-4C 10 July 2006 GSLV Launch unsuccessful
21 INSAT-4B 12 March 2007 Ariane-5 Mission Completed
22 INSAT-4CR 2 September 2007 GSLV
23 GSAT-4 15 April 2010 GSLV Launch unsuccessful
24 GSAT-5P 25 December 2010 GSLV-F06 Launch unsuccessful
25 GSAT-8 21 May 2011 Ariane-5
26 GSAT-12 15 July 2011 PSLV-C17
27 GSAT-10 29 September 2012 Ariane-5
28 GSAT-7 30 August 2013 Ariane-5
29 GSAT-14 5 January 2014 GSLV-D5
30 GSAT-16 7 December 2014 Ariane-5
31 GSAT-6 27 August 2015 GSLV-D6
32 GSAT-15 11 November 2015 Ariane-5
33 GSAT-18 6 October 2016 Ariane-5
34 GSAT-9 5 May 2017 GSLV-F09
35 GSAT-19 5 June 2017 GSLV MkIII - D1
36 GSAT-17 29 June 2017 Ariane-5
37 GSAT-6A 29 March 2018 GSLV-F08 Failed in Orbit
38 GSAT-29 14 November 2018 GSLV MkIII-D2
39 GSAT-11 5 December 2018 Ariane-5
40 GSAT-7A 19 December 2018 GSLV-F11
41 GSAT-31 6 February 2019 Ariane-5 VA-247
42 GSAT-30 17 January 2020 Ariane-5 VA-251
43 CMS-01 (GSAT-12R) 17 December 2020 PSLV-C50
44 CMS-02 (GSAT-24) 23 June 2022 Ariane-5 VA-257
45 INSAT-3DS 17 February 2024 GSLV Mk II
46 GSAT-20 (CMS-03) Q2 2024 Falcon 9 Block 5 Planned
47 GSAT-22[29] 2025 LVM3 Planned
48 GSAT-23[29] 2025 LVM3 Planned

See also


  1. ^ GSAT-F06
  2. ^ ISRO page of INSAT-2E
  3. ^ "ISRO page of INSAT-3A". Archived from the original on 1 February 2009. Retrieved 9 February 2016.
  4. ^ "ISRO page of INSAT-3C". Archived from the original on 1 May 2009. Retrieved 9 February 2016.
  5. ^ "INSAT-3D India's Advanced Weather Satellite" (PDF). Archived from the original (PDF) on 5 August 2013. Retrieved 17 March 2013.
  6. ^ "INSAT-3DR". World Meteorological Organization. 5 June 2012. Retrieved 29 June 2016.
  7. ^ "ISRO page of INSAT-3E". Archived from the original on 17 June 2009. Retrieved 9 February 2016.
  8. ^ S, Madhumathi D. (April 2014). "After 10 years in orbit, INSAT-3E expires". The Hindu.
  9. ^ "ISRO page of INSAT-4A". Archived from the original on 28 June 2009. Retrieved 9 February 2016.
  10. ^ "ISRO page of INSAT-4B". Archived from the original on 31 October 2014. Retrieved 9 February 2016.
  11. ^ "Successful post mission disposal of INSAT-4B Satellite - ISRO". Archived from the original on 7 February 2022. Retrieved 8 February 2022.
  12. ^ Parashar, Sachin (11 October 2010). "China hitting India via Net worm?". The Times of India. Archived from the original on 3 November 2012.
  13. ^ "INSAT-4CR successfully placed in orbit". Times of India. 2 September 2007. Archived from the original on 21 February 2009.
  14. ^ "INSAT-4CR now in near geo-synchronous orbit". Telecom Asia. 17 September 2007. Retrieved 16 January 2023.
  15. ^ "ISRO refutes INSAT-4CR 'disappearance' story". Hindustan Times. Archived from the original on 5 June 2011.
  16. ^ "Isro-Saarc satellite to be a communication vehicle". Deccan Herald. Deccan Herald News Service. 12 January 2015. Retrieved 22 April 2015.
  17. ^ "GSAT-9". Indian Space Research Organisation. Archived from the original on 15 April 2021. Retrieved 29 May 2017.
  18. ^ "ISRO's Diwali Gift: GSAT-15 Communications Satellite Successfully Launched". NDTV. 11 November 2015.
  19. ^ "Salient features of GSAT-17". ISRO Satellite Centre. Archived from the original on 22 July 2017. Retrieved 29 June 2017.
  20. ^ "Heaviest satellite of ISRO launched". The Hindu. 30 June 2017. Retrieved 14 March 2018.
  21. ^ "Annual Report: 2014-2015" (PDF). Indian Space Research Organisation. 2015. p. 26. Archived from the original (PDF) on 4 March 2016. Retrieved 14 November 2018.
  22. ^ "First Prototype of ISRO's Semi-Cryogenic Engine To Be Ready By 2016". AA Me, IN. 19 August 2015. Retrieved 26 October 2016.
  23. ^ "GSat 19". Gunter's Space Page. Retrieved 27 May 2016.
  24. ^ "Isro gets nod for semi-cryogenic engine, will boost GSLV's lift capability by 1 tonne". The Times of India. 8 June 2018.
  25. ^ "GSLV MkIII-D2 successfully launches GSAT-29". Archived from the original on 14 November 2018. Retrieved 14 November 2018.
  26. ^ "GSAT-29 - ISRO". Archived from the original on 12 November 2018. Retrieved 12 November 2018.
  27. ^ Laxman, Srinivas; Singh, Surendra (5 December 2018). "Exseed Sat 1: Mumbai startup first Indian private firm to have satellite in space". The Times of India. Retrieved 13 January 2021.
  28. ^ "India in Space through 2019: From RISAT, ASAT and Chandrayaan 2 to big wins for private space". Tech2. 25 December 2019. Retrieved 13 January 2021.
  29. ^ a b Chethan Kumar (5 October 2021). "Space PSU NSIL to launch 4 more demand-driven communications satellites". Times of India. Retrieved 25 May 2023.