Chennai, July 21 (IANS) The countdown for Monday's Chandrayaan-2 mission launch on will start at 6.43 p.m. today, ISRO chairman K. Sivan has said.

During the countdown, the rocket and spacecraft's systems will undergo checks and fuel will be filled to power the rocket engines.

The GSLV-Mk III rocket with Chandrayaan-2 spacecraft was originally scheduled for flight on July 15 at 2.51 a.m. However, the flight was postponed due to detection of a technical snag one hour prior to the rocket lift off.

--IANS vj/in/rtp