ISRO to start countdown for INSAT-3DR launch on Wednesday

The GSLV-F05 flight carrying the weather satellite is scheduled to be launched on September 8

A 29-hour countdown to launch the 2211 kilogram advanced weather satellite INSAT-3DR into the Geostationary Transfer Orbit (GTO) will start at 11.10 am on Wednesday. The satellite is scheduled to be launched India's tenth Geosynchronous Satellite Launch Vehicle (GSLV) flight GSLV-F05, at 4.10 pm, on Thursday.

The Mission Readiness Review (MRR) committee and Launch Authorization Board (LAB) have cleared the countdown and the launch on September 8, 2016, will be from the Second Launch Pad at Satish Dhawan Space Centre SHAR (SDSC SHAR), Sriharikota, stated ISRO.

After reaching GTO, INSAT-3DR will use its own propulsion system to reach its final geosynchronous orbital home and will provide a variety of meteorological services to the country. The imager in the satellite will generate images of the Earth disk from geostationary altititude of 36,000 km every 26 minutes and provide information on various parameters including outcoing long-wave radiation, quantitative precipitation estimation, sea surface temperature, snow cover, cloud motion winds, among others.

"GSLV-F05 is the flight in which the indigenously developed Cryogenic Upper Stage (CUS) is being carried on-board for the fourth time during a GSLV flight. GSLV-F05 flight is significant since it is the first operational flight of GSLV carrying CUS," said an ISRO statement.

A cryogenic rocket stage is more efficient and provides more thrust for every kilogram of propellant it burns compared to solid and earth-storable liquid propellant rocke stages. However, it is technically very complex comparitively, due to its use of propellants at extremely low temperatures and the related thermal and structural challenges.

The vehicle is configured with all its three stages including the CUS similar to the ones successfully flown during the previous GSLV-D5 and D6 missions in January 2014 and August 2015. GSLV-D5 and D6 successfully placed GSAT-14 and GSAT-6 satellites carried on-board in the intended GTOs accurately.

INSAT-3DR, which has a 1255 kg of propellant to raise the satellite from the GTO to the final orbit and maintain it in its orbital slot during its life, has a solar array generating 1,700 watts of power.