Chandrayaan 2, India's ambitious lunar mission, is scheduled to make a soft-landing on the surface of the moon at 1:55 am on Saturday. The tricky manoeuvre of 35 km, till the lander and the rover land on the moon's surface without any injury, will be "15 minutes of terror" even for the top scientists at space agency ISRO.
"It is like suddenly somebody comes and gives you a newborn baby in your hands. Will you be able to hold without proper support? The baby will move this way that way but we should hold it. It like that, the lander will go this way or that but at the same time it has to be brought just like a baby," ISRO chief Dr K Sivan told NDTV.
The moon lander Vikram that separated from its orbiting mothership has already performed two manoeuvres to lower its altitude for a perfect touchdown between 1:30 am and 2:30 am on Saturday.
"This is a very complex process and it is new for us. It is a complex process even for those who have already done it. We are doing this for the first time, so it will be fifteen minutes of terror for us," Dr Sivan said.
Landing is especially difficult on the moon since the atmosphere is very thin and parachutes cannot be used to slow down.
Prime Minister Narendra Modi will be at the ISRO headquarters in Bengaluru around midnight to watch the event. Over 60 high school students across the country who cleared an online space quiz last month will watch the soft landing of the mission with the Prime Minister.
India is seeking to become the fourth nation after Russia, the United States and China to land a spacecraft on the moon.
"We do realise that space technology and space activity are always fraught with a lots of ifs and buts. No matter what you may have done, there could always be surprises... Our effort is to do best of the preparation, and then be prepared for the worst," former ISRO chairman Dr AS Kiran Kumar told NDTV.
Chandrayaan 2 lifted off from the Indian Space Research Organisation's (ISRO's) spaceport at Sriharikota in southern Andhra Pradesh on July 22. The lift-off was successful in its second attempt, a week after it was aborted just under an hour from its launch due to a technical glitch.
The mission stands out because of its low cost, with just about Rs. 1,000 crore spent - a much smaller price tag compared to similar missions by other countries.