The 51-hour countdown for India's landmark 100th space mission began on Friday with Indian Space Research Organisation's old warhorse Polar Satellite Launch Vehicle rocket all set to soar into space on September 9 with two foreign satellites from the spaceport of Sriharikota in Andhra Pradesh.
The Launch Authorisation Board for Polar Satellite Launch Vehicle (PSLV-C21)/SPOT-6/PROITERES mission, which met on September 5 at the Satish Dhawan Space Centre in Sriharikota, cleared the launch at 09:51 hrs, ISRO said.
The countdown commenced at 6:51 am, ISRO said in a statement, adding that propellant-filling operations of liquid propellant second stage and fourth stage of the launch vehicle would be carried out during the countdown.
Prime Minister Manmohan Singh will witness the mission, in which 720-kg SPOT-6 remote sensing satellite from France (built by ASTRIUM SAS) and a 15-kg Japanese spacecraft PROITERES would be placed in orbit by ISRO's PSLV C-21.
During the countdown, mandatory checks on the launch vehicle and spacecraft would be carried out and charging of batteries and pressurisation of propellant tanks on board the satellite would be performed, ISRO said.
"Readiness of various ground systems such as tracking radar systems and communication networks will also be ascertained. PSLV-C21 will inject SPOT-6 and PROITERES satellites into an orbit of 655 km altitude at an inclination of 98.23 degree," it added.