Shriharikota(BS):The 56-hour 30-minute countdown for the Mars Mission commenced on Sunday at the Sriharikota space station, about 100 km from Chennai.

The countdown started at 06:08 hrs (IST) on Sunday for the scheduled launch of the PSLVC25. The spacecraft is scheduled to take off at 2.38 pm on Tuesday.

On Saturday, all the Pre-Countdown activities for ISRO’s Rs 450 crore Mars Orbiter Mission have been completed satisfactorily, said ISRO.

The pre-countdown activities for ISRO’s Mars Orbiter Mission commenced on Saturday morning with the filling of Strontium Perchlorate injectant in the Secondary Injection Thrust Vector Control (SITVC) System of the First stage of PSLV C25.

The SITVC system enables Pitch and Yaw control during the thrust phase of the first stage solid motor of PSLV, which will carry the 1,337 kg Mars Orbiter Satellite into a 250 km X 23,500 km elliptical orbit.

The Satellite will be further navigated to a hyperbolic departure technology and thereafter it traverses an interplanetary cruise trajectory before reaching the intended orbit around the Mars, according to ISRO.

The vehicle is expected to reach its destination sometime in September 2014.

On October 31, ISRO conducted rehearsal, which started at 06:08 hrs at Sriharikota, about 100 kms from Chennai, on Thursday.

Except for pressing the ignite button, all other procedures were checked and see whether all preparations are in place during the rehersal, said an official.

The launch rehearsal simulated the entire procedure of the final eight hours of the countdown, right up to the ignition, after which the system was shut down.

The dry run will demonstrate mission-readiness and on November 1 the Launch Authorisation Board took the final call on initiating the 56-hour-30-minute-long countdown.