Chennai, Jun 28 : The 64-hour countdown for the launch of India's first dedicated navigational satellite IRNSS-1A from the spaceport of Sriharikota, about 100 km from here, would commence at 0700 hrs tomorrow.
ISRO sources told UNI today the 1,425 kg satellite would be launched by the XL version of India's homegrown rocket PSLV-C22 at 2341 hrs on July 1. The sources said all systematic checks were completed successfully and the launch rehearsal was in progress at the Satish Dhawan Space Centre. The 44 metre tall launch vehicle with a lift off mass of 320 tons would be launched from the first launch pad.
"The around 64 hrs countdown for the launch of IRNSS-1A by the ISRO's workhorse satellite launch vehicle PSLV-C22 will commence at 0700 hrs tomorrow morning", the sources said. During the countdown filling of solid and liquid propellants in the four stage launch vehicle will be taken up, they added.
About 20 minutes after the lift off, the IRNSS-1A would be placed in a sub Geosynchronous Transfer Orbit (sub GTO) with a 284 km perigee (nearest point to Earth) and 20,650 km apogee (farthest point from the earth) with an inclination of 17.86 deg with respect to the equatorial plane.PSLV-C22 is the 24th PSLV Mission of ISRO. The 'XL' version of PSLV, with six extended solid strap-on motors, would be used for the mission. This was for the fourth time ISRO would be using its XL version of PSLV, the earlier three being PSLV-C11 for the prestigious Chandrayaan-1, PSLV-C17 GSAT-12 and PSLV-C19 RISAT-1 missions.
IRNSS-1A, the first Indian Navigation Satellite, was earlier scheduled for launch on June 12 at 0101 hrs. But it was deferred by a fortnight after an anomaly was detected. "During the electrical checks of the launch vehicle, an anomaly was observed in one of the electro-hydraulic control actuators in the second stage. It has been decided to replace the actuator", the sources said. Since the replacement of the control actuator needs two weeks of activity at the Launch Pad and the Vehicle Assembly, the launch was deferred by two weeks and it is now slated to take off on July 1.