<br/>The 51-hour countdown for the launch of ISRO's PSLV C-15 from the Satish Dhawan Space Centre at Sriharikota began at 6.52 this morning. ISRO spokesperson, Satish said all the pre-launch parameters are proceeding smoothly. <br/><br/>PSLV C-15 will blast off at 9.23 AM on Monday. The launch vehicle will put into orbit five satellites including remote sensing satellite CARTOSAT-2B from India, ALSAT from Algeria, two Nano satellites from Canada and Switzerland and a very small satellite, Studsat, built by seven engineering students of Andhra Pradesh and Karnataka.