Indian Space Research Organization is all set for Mars Mission`s launch rehearsal today. The final countdown for India`s ambitious Rs.430-crore Mars Orbiter Mission (MOM) will begin on Sunday morning, while the full launch rehearsal will be on Thursday. The countdown for the Mars Orbiter Mission will begin Sunday at 6.08 a.m. The Polar Satellite Launch Vehicle (PSLV-C25) rocket carrying the MOM will blast off at 2.38 p.m Nov 5 from here around 80 km from Chennai.The launch rehearsal of the rocket Polar Satellite Launch Vehicle (PSLV-C25) will begin Thursday and last over eight hours. During the launch rehearsal, except for pressing the ignition button, every other activity related to the rocket launch will be carried out.