The 20-hour countdown for launch of Chandrayaan-2, India’s first unmanned mission expected to land on the lunar surface, began at 6.51 am on Sunday. India's heavy rocket nicknamed the 'Bahubali' carrying the Chandrayaan-2 spacecraft will lift-off on Monday i.e. July 15 at 2:51 am from India's only space port at Sriharikota in Andhra Pradesh.
"The countdown started at 6.51 am," K Sivan, Chairman, Indian Space Research Organisation (ISRO), said.
Here are 10 important things you need to know:
1. It is the Indian Space Research Organisation's first mission to land on any celestial body and a follow-up to Chandrayaan-1 launched in 2008.
2. Chandrayaan-1 mission had 11 payloads -- five from India, three from Europe, two from the US and one from Bulgaria.
3. The objective of the mission is to take up a detailed study on the understanding of the origin and evolution of the Moon.
4. The 640-tonne rocket Geosynchronous Satellite Launch Vehicle-Mark III (GSLV-Mk III) standing at about 44 metre tall, nicknamed the 'Bahubali', will carry the 3.8-tonne Chandrayaan-2 spacecraft.
5. President Ram Nath Kovind will be at Sriharikota to witness the midnight launch. He will be the third sitting president to witness a live launch from the spaceport.
6. On successful completion of the mission, India will become the fourth country to soft-land spacecraft on the lunar surface after the US, Russia, and China.
7. About 16-minutes into its flight, the Rs. 375 crore GSLV-Mk III rocket is expected to sling the Rs 603 crore Chandrayaan-2 into an Earth parking 170x40400 km orbit.
8. From there, it will be a long journey for the Chandrayaan-2 spacecraft carrying lander-Vikram and rover-Pragyaan will travel further to the moon.
9. The Lander Vikram is expected to make a soft landing on the moon on September 6 and then Pragyaan will roll out to carry out in-situ experiments.
10. To date, ISRO has sent up three GSLV-Mk III rockets. The first one was on 18.12.2014 carrying Crew Module Atmospheric Reentry Experiment. The second and third GSLV-Mk III went up on 5.2.2017 and 14.11.2018 carrying communication satellites GSAT-19 and GSAT-29 respectively.