Sriharikota:�ISRO's sixth navigation satellite IRNSS-1F was successfully launched today onboard PSLV C32 from the spaceport here. In a textbook mission, Indian Space Research Organisation's workhorse PSLV-C32 lifted off from the Satish Dhawan Space Centre here, about 100 km from Chennai, at 4.01 PM and later injected the IRNSS-IF in sub-Geosynchronous Transfer Orbit (sub GTO). IRNSS-1F is the sixth in the series of seven satellites proposed under the Indian Regional Navigational Satellite System (IRNSS) that will offer navigational services on par with the US-based Global Positioning System. The first in this series was launched in July 2013. "Polar Satellite Launch Vehicle C-32 has put the satellite in the right orbit. We have only one more in the constellation to complete the regional navigational system, which we hope to do next month," a jubilant ISRO Chairman A S Kiran Kumar said at the Mission Control Centre. For today's launch, the "XL" variant was used as in the previous launches of IRNSS satellites, given its capacity to carry load. Along with the navigation and ranging payload, which will transmit navigation service signals to users, IRNSS-1F also carries a highly accurate "Rubidium atomic clock" with it. IRNSS-1F has a 12-year mission life. Though the IRNSS system has already come into operation with the minimum complement of four satellites, the total of seven satellites would make it more "accurate and efficient", ISRO officials said.