|Mission duration||Planned: 12 years |
Duration: 13 years, 10 months, 5 days
|Launch mass||3,028 kilograms (6,676 lb)|
|Dry mass||1,335 kilograms (2,943 lb)|
|Start of mission|
|Launch date||11 March 2007, 22:03UTC|
|Launch site||Kourou ELA-3|
|Longitude||85.5° E (relocated on 20 Feb 2020)|
83° E (relocated on 12 Oct 2019)
|Semi-major axis||42,163.57 kilometres (26,199.23 mi)|
|Perigee altitude||35,776 kilometres (22,230 mi)|
|Apogee altitude||35,809 kilometres (22,251 mi)|
|Epoch||11 November 2013, 22:16:22 UTC|
Built by the Indian Space Research Organisation, INSAT-4B is based upon the I-3K satellite bus. It had a mass at launch of 3,028 kilograms (6,676 lb), with a dry mass of 1,335 kilograms (2,943 lb) and was expected to operate for twelve years. Two solar arrays power the satellite, while its communications payload consists of twelve C and twelve Ku band transponders.
Arianespace was contracted to launch INSAT-4B using an Ariane 5 ECA carrier rocket. The launch occurred on 11 March 2007 at 22:03 UTC, from ELA-3 at Kourou. The Skynet 5A military communications satellite for the British Ministry of Defence was launched aboard the same rocket.
INSAT-4B was successfully inserted into geosynchronous transfer orbit, from which it raised itself into geostationary orbit using a liquid-fuelled apogee motor. It received the International Designator 2007-007A and Satellite Catalog Number 30793. As of 11 November 2013, it is in an orbit with a perigee of 35,776 kilometres (22,230 mi), an apogee of 35,809 kilometres (22,251 mi), inclination of 0.07 degrees and an orbital period of 23.93 hours.
On 10 July 2010 INSAT-4B suffered a disruption in power supply from one of the two solar panels, rendering half of its transponder capacity useless. After review the cause of malfunction was found out to be electric arcing in slip ring of one of the solar panels. Similar partial power supply failure also affected Eutelsat W2M now known as Afghansat 1 and caused delay in launch of GSAT-8 due to required design changes in relevant power systems of satellite bus.
On 11 November 2017, INSAT-4B maneuvered to lower its altitude and drifted eastward to reach new slot at 111.2°E on 18 December 2017.