The stage is all set for the launch of the GSLV D3 from the Satish Dhawan Space Centre at Sriharikota at 4.27 pm today. <br/><br/>The 29-hour countdown for the lift-off began at 11.27 a.m. yesterday is progressing smoothly. <br/><br/>ISRO Spokesman Mr Satish has said that mandatory checks of the vehicle and charging of the batteries in both the rocket and the satellite are being undertaken during the countdown. <br/><br/>AIR correspondent reports that for the first time, the launch vehicle is powered by a totally indigenous cryogenic engine and will put an advanced communication satellite, GSAT-4, in orbit. <br/><br/>The GSAT-4 which weighs 2,220 kg will carry communication and navigation payloads. The communication payload Ka-band transponder will be used for wide-band multimedia services, e-commerce and high bandwidth Internet. <br/><br/>The navigation payload the GPS-aided Geo-Augmented Navigation (GAGAN) system will help commercial aircraft to land accurately in runways in poor visibility conditions. <br/><br/>GSAT 4 will have a life span of 7 years. <br/><br/>A successful launch will catapult India into the 5 elite group of nations including US, Russia. France. <br/><br/>Japan and China which have mastered the highest level of propulsion technology. <br/>