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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]

INSAT 4E

GSAT-6 seen with two halves of payload faring of GSLV-D6
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: 6 years, 11 months, 24 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 (2015-08-27UTC11:22Z) 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)[clarification needed]
GSAT ← GSAT-16 GSAT-15 →

Satellite

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.[2] GSAT-6 uses a 0.8 meter (fixed) and one 6 meter S-Band unfurlable antenna (transmit and receive).[3]

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.[4]

GSAT-6 is identical in configuration to GSAT-6A which was launched later.

Launch

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.[5]

Orbit raising

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.[6][7]

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.[8]

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.[9] 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.[10]

See also

• Indian military satellites
• GSAT-6A
• Indian National Satellite System
• GSAT
• List of Indian satellites
• Satellite television

References

External links

• GSAT-6 at ISRO.gov.in

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