The countdown for the launch of India's navigation satellite IRNSS 1F is progressing smoothly at Satish Dhawan Space Centre in Sriharikota. It will be launched by polar synchronous launch vehicle PSLV C32 at 4 pm tomorrow. In 20 minutes 12 seconds from the time of lift off, the rocket is expected to put the payload in the planned orbit. <br/><br/>It is the sixth in a series of seven satellites to establish India's own space-based positional information service system. As part of the countdown process, the ISRO scientists are now engaged in filling operations of the two liquid fuel stages of the four stage rocket PSLV C-32. It will undertake its journey with the navigation satellite IRNSS-1F in its extended version. <br/><br/>Given the lift off mass of the payload of 1425 kilogram and the sub-geosynchrnous transfer orbit where the satellite needs to be placed, the launch vehicle has strap-on motors integrated with it to give the extra thrust for its journey. <br/><br/>It is the 34th flight for the PSLV and the second launch for the ISRO this year. The PSLV has proved its reliability by successfully undertaking its mission for 33 flights continuously.