The PSLV-C39 has failed in its mission today, as its heat shield failed to separate, preventing the satellite IRNSS-1H to reach its designated orbit. It was planned to insert the new navigation satellite IRNSS-1H today in a sub-geosynchronous transfer orbit to replace the ailing IRNSS-1A in space. <br/><br/>The IRNSS series satellites are part of the indigenous navigation system called NavIC. As per the original plans, the rocket PSLV C39 lifted off from the second launch pad at the Satish Dhawan Space Centre, Sriharikota at 7 pm today, with the IRNSS-1H on board. <br/><br/>The payload fairing that keeps the satellite from outside heat should have opened up and shed itself off after the second stage of the vehicle s ignited. However, ISRO Chairman AS Kiran Kumar told the waiting journalists in Sriharikota that the heat shield failed to function. <br/><br/>He said all stages of the rocket performed normally, except the heat shield. He said the satellite is still inside the payload fairing in the rocket, as it is unable to eject out. He said the flight data would be analysed, and the cause of the failure would be known afterwards. More from our correspondent:<br/><br/>The PSLV rocket is normally known for its reliability. But the failure today has come as a blot on its impressive record so far. The PSLV has been serving as a trusted work-horse so far, except its first ever flight. It has been used for launching the record 104 satellites recently and also for the prestigious space science missions like Mangalyaan and Chandrayaan-I. However, ISRO Chairman AS Kiran Kumar expressed satisfaction over its performances during all other stages except the heat shield separation. It ought to have opened up during the ignition of the second stage. <br/><br/>As it failed to shed itself off, its weight served to drag down the launch vehicle during its journey into space, reducing the rocket's speed. The exact reasons for its failure would be ascertained later to take remedial measures and bring the reputation of the PSLV back to its original glory. Meanwhile, launching a new satellite under the Indian navigation system NavIC has to wait further.