GSat-8

GSAT-8

India

Spacecraft nº:

Indian spacecraft nº: 60

Also called: Insat-4G

Designation	37605 / 11022A
Launch date	20 May 2011 - 20:38 UT
Launch site	Ko, ELA-3
Launch vehicle	Ariane-5ECA (V-202)
Mission	Government: Communication/Navigation
Geostationary orbit:
Perigee / Apogee	35782 x 35796 km
Eccentricity	1.66E-04
Inclination	0.09 deg
Period	1436.23 min

Prime manufactor	ISRO
Platform	ISRO I3K
Operator	Indian Space Research Organization (ISRO)
Mass at launch	3093 kg
Dry Mass	1426 kg
Basic shape	cuboid
Dimension (m)	2.0 x 1.77 x 3.1m
Equipment	18 Ku-band transponders, 2 BSS transponders, GAGAN payload
Solar array	2 Solar array providing 6242 watts three 100 Ah Lithium Ion batteries
Stabilization	3-axis body stabilised in orbit using Earth Sensors, Sun Sensors, Momentum and Reaction Wheels, Magnetic Torquers and eight 10 Newton and eight 22 Newton bipropellant thrusters
Propulsion	440 Newton Liquid Apogee Motors (LAM) with mono Methyl Hydrazine (MMH) as fuel and Mixed oxides of Nitrogen (MON-3) as oxidizer for orbit raising.
Antennas	Two indigenously developed 2.2 m diameter transmit/receive polarisation sensitive dual grid shaped beam deployable reflectors with offset-fed feeds illumination for Ku-band; 0.6 m C-band and 0.8x0.8 sq m L-band helix antenna for GAGAN
DC power	6242 W
Design lifetime	12 yrs - still active

Date	Position	Remarks
Sept 2011	55° E

India's GSAT 8 satellite will be ready for communications duties by mid-June 2011 to start a 12-year mission beaming broadcast and navigation signals. It will be parked along the equator at 55 degrees east longitude after a series of rocket burns to guide GSAT 8 into the correct position in space. The spacecraft will augment India's INSAT communications satellite fleet. GSAT 8 will be used for direct-to-home broadcasting, data collection, news-gathering and other domestic needs. The satellite also carries a radio navigation instrument called GAGAN to augment GPS navigation signals. It is the first of multiple satellites with the GAGAN payload, which is designed to improve air navigation in India.

Direct-to-home broadcast and other domestic needs. Equipped with GAGAN (GPS Aided GEO Augmented Navigation).
GSAT-8 is an ISRO I3K satellite with a communications payload and also the GAGAN navigation transponder. On May 28, 2011 GSAT-8 was drifting over the Indian Ocean in a 35539 x 35764 km x 0.1 deg orbit.
The Indian Space Research Organization's GSAT program has now superseded the old INSAT system; GSAT-8 was formerly known as INSAT 4G. GSAT-1, 2 and 3 were launched in 2001 to 2004 on test flights of ISRO's GSLV rocket; GSAT-4 and GSAT-5P were lost in failures of the GSLV in 2010. GSAT-6 and GSAT-7 have not yet been launched.
GSAT-8 had a liftoff mass of 3,150 kg. and is designed for a mission life of 12 years. Operating with a payload power of 5,300 Watts, the satellite will be located at an orbital position of 55 deg. East longitude following its deployment by Ariane 5.
On May 25, 2011, ISRO announced that the satellite had reached Geosynchronous orbit with an orbital period of 23 hours 45 minutes. The satellite's orbit has a perigee of 35,543 km, apogee of 35,770 km and an orbital inclination of 0.04 deg with respect to the equatorial plane. The solar arrays on both sides of the satellite had been deployed and they were tracking the Sun and generating electrical power. The solar arrays are designed to generate 6,240 W of electrical power. Two large dual grid Ku-band antennae had been opened and were pointing towards the Earth.

Ref.: #7(JR642), #14, #120, #126, #226, #228 - update: 22.12.13