Mission type | Communication |
---|---|
Operator | INSAT |
COSPAR ID | 2015-041A |
SATCAT no. | 40880 |
Website | https://www.isro.gov.in/Spacecraft/gsat-6 |
Mission duration | Planned: 9 years Elapsed: 8 years, 6 months, 11 days |
Spacecraft properties | |
Bus | I-2K |
Manufacturer | ISRO Satellite Centre Space Applications Centre |
Launch mass | 2,117 kilograms (4,667 lb) |
Dry mass | 985 kg (2,172 lb) |
Power | 3.1 kilowatts |
Start of mission | |
Launch date | 27 August 2015, 11:22 UTC |
Rocket | GSLV Mk.II D6 |
Launch site | Satish Dhawan SLP |
Contractor | ISRO |
Orbital parameters | |
Reference system | Geocentric |
Regime | Geostationary |
Longitude | 83°E |
Epoch | Planned |
Transponders | |
Band | 5, C x S transponders (9 megahertz bandwidth) 5, S x C transponders (2.7 megahertz bandwidth) |
INSAT-4E, also known as GSAT-6, is a member of the INSAT family and is a multimedia communication satellite that will offer 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. The satellite can be used for other social and strategic applications. [1] [2]
INSAT-4E has five C x S transponders each of 9 MHz bandwidth and five S x C transponders each of 2.7 MHz bandwidth which will together cover the entire country. [3] GSAT-6 uses a 0.8 meter (fixed) and one 6 meter S-Band unfurlable antenna (transmit and receive). [4]
The unfurlable antenna weighing 18 kg has CFRP truss construction with aluminium alloy joints and its parabolic gold plated molybdenum mesh is supported and shaped by cable mesh structures. [5]
The cost of GSAT-6 satellite is ₹232 crore [6] and it is identical in configuration to GSAT-6A which was launched later.
ISRO successfully launched INSAT-4E on 27 August 2015, using a GSLV D6 Mk.II rocket flying from the Satish Dhawan Space Centre and inserted into a Geostationary Transfer Orbit (GTO) with injection parameters of 170 km x 35945 km, 19.96 degree inclination. [7] The cost of launch vehicle was around ₹276 crore. [6]
Maneuvers to move the satellite into its designated geosynchronous orbit at 83 degrees East longitude were initiated on 28 August 2015 by firing motors on board the GSAT-6 satellite.
The GSAT-6 satellite's Liquid Apogee Motor (LAM) was fired for 3385 seconds at 08:35 hours IST on August 28 during the first orbit raising operation and modified the satellite orbit to 8,408 km (perigee height) by 35,708 km (apogee height) with an inclination of 7.5 degree and an orbital period of 13 hours, 15 minutes and 24 seconds. [8] [9]
Second orbit raising operation of GSAT-6 was successfully completed by firing the Apogee Motor for 2663 seconds at 11:10:53 hours IST on Aug 29, 2015. Realized orbit was 26,998 km (perigee height) by 35,682 km (apogee height) with an inclination of 0.115 degree and an orbital period of 20 hours and 15 minutes. [10]
Third orbit raising operation of GSAT-6 was successfully completed by firing the Apogee Motor for 580.32 seconds at 07:46 hours IST on Aug 30, 2015. Deployment of the unfurlable antenna (UFA) also successfully completed with this. [11] The satellite was at 78 degrees east longitude and was drifting towards its final slot at 83 degrees east.
GSAT-6 was successfully positioned in its orbital slot of 83 degree east and collocated with INSAT-4A, GSAT-12, GSAT-10 and IRNSS-1C on September 6, 2015, morning, after carrying out four drift arresting maneuvers. [12]
According to Comptroller and Auditor General of India report submitted to parliament in 20 December 2022, the GSAT-6 satellite has remained largely underutilized since its launch in August 2015 which is almost half of the expected operational life of 12 years. The audit observed the lack of coordination between Department of Space and DRDO and the delay in establishing ground segment by DRDO as the reason behind this disuse. According to Department of Space the 20 per cent of the GSAT-6 capacity was used for its research projects and societal applications but was not aware of the status of utilization of the remaining capacity. [6]
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. 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.
Geosynchronous Satellite Launch Vehicle (GSLV) is a class of expendable launch systems operated by the Indian Space Research Organisation (ISRO). GSLV has been used in fifteen launches since 2001.
GSAT-3, also known as EDUSAT, was a communications satellite which was launched on 20 September 2004 by the Indian Space Research Organisation. EDUSAT is the first Indian satellite built exclusively to serve the educational sector. It is mainly intended to meet the demand for an interactive satellite-based distance education system for the country.
The GSAT satellites are India's indigenously developed communications satellites, used for digital audio, data and video broadcasting. As of 5 December 2018, 20 GSAT satellites of ISRO have been launched out of which 14 satellites are in service.
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INSAT-3A, a multipurpose satellite built by ISRO was launched by Ariane in April 2003. It is located at 93.5 degree East longitude. It is third satellite in INSAT-3 series after INSAT-3B & INSAT-3C. Built at a cost of $53 mn, it provides communication, weather, and search and rescue services.
INSAT-3C is a multipurpose satellite built by ISRO and launched by Arianespace in Jan 2002. INSAT-3C is the second satellite of the INSAT-3 series. All the transponders provide coverage over India. Insat-3C is controlled from the Master Control Facility at Hassan in Karnataka. It will provide voice, video and digital data services to India and neighboring countries.
INSAT-4CR was a communications satellite operated by ISRO as part of the Indian National Satellite System. Launched in September 2007, it replaced the INSAT-4C satellite which had been lost in a launch failure the previous year. The satellite was initially stationed in geostationary orbit at a longitude of 74 degrees east, with expected operational life of at least ten years, however this may have been reduced by the underperformance of the Geosynchronous Satellite Launch Vehicle which placed it into orbit. INSAT-4CR is planned to be replaced by GSAT-31, which was launched on February 6, 2019.
GSAT-7 or INSAT-4F is a multi-band military communications satellite developed by the Indian Space Research Organisation. The Indian Navy 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.
INSAT-4B was an Indian communications satellite which forms part of the Indian National Satellite System. Launched in 2007, it was placed in geostationary orbit at a longitude of 93.48° East.
IRNSS-1C is the third out of seven in the Indian Regional Navigation Satellite System (IRNSS) series of satellites after IRNSS-1A and IRNSS-1B. The IRNSS constellation of satellites is slated to be launched to provide navigational services to the region. It was launched on 15 October 2014 at 20:02 UTC by PSLV-C26 and will be placed in geostationary orbit.
GSAT-7A is an advanced military communications satellite meant primarily for the Indian Air Force with Indian Army using 30% of capacity.
GSAT-6A was a communication satellite launched by the Indian Space Research Organisation (ISRO) It featured a 6-metre (20 ft) unfurlable S-band antenna similar to the one used on GSAT-6. Around 17 minutes after lift-off, the three stage GSLV Mk.II rocket flying on GSLV F08 mission successfully injected the satellite into a geosynchronous transfer orbit. Due to power failure during its orbit raising burns the communication was lost with GSAT-6A before it could reach its final circular geostationary orbit (GSO).
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