India is ready to launch its second lunar mission: if successful, it will become the fourth country to make a soft landing on the surface of the Moon.
Only the United States, China and the former Soviet Union have been able to do so.
The $ 150 million mission, Chandrayaan-2, aims to collect data on water, minerals and rock formations on the Moon.
The landing and rover are expected to land near the lunar south pole in early September, becoming the first spacecraft to land in that region.
The head of the Indian Space Research Organization (ISRO), K Sivan, said it was "the most complex space mission the agency has ever undertaken."
The launch of the Indian-made satellite is scheduled for 2:51 local time Monday (21:21 GMT Sunday) from the Sriharikota space station on the east coast of India.
The country's first lunar mission in 2008, Chandrayaan-1, did not land on the lunar surface, but it did the first and most detailed search for water on the Moon using radars.
What is this mission about?
Chandrayaan-2 (Lunar Vehicle 2) will attempt a soft landing near the Moon's little explored south pole.
The mission will focus on the lunar surface, looking for water and minerals and measuring the earthquakes of the moon, among other things.
India is using its most powerful rocket, the Mark III Geosynchronous Satellite Launch Vehicle (GSLV Mk-III), in this mission. Its weight is 640 tons (almost 1.5 times the weight of a fully loaded 747 jumbo jet) and at 44 meters (144 feet) it is as tall as a 14-story building.
The spacecraft weighs 2,379 kg (5,244 lb) and has three distinct parts: an orbiter, a lander and a rover.
The orbiter, which has a mission life of one year, will take pictures of the lunar surface and "smell" the dim atmosphere.
The landing module (called Vikram, after the founder of Isro) weighs about half, and carries within its belly a lunar vehicle of 27 kg with instruments to analyze the lunar soil. In its 14-day life, the rover (called Pragyan – wisdom in Sanskrit) can travel up to half a kilometer from the lander and send data and images to Earth for analysis.
"India can expect to get the first selfies from the lunar surface once the rover does its job," said Dr. Sivan.
A new frontier for the Indian space program.
For the science writer Pallava Bagla.
A soft landing in another planetary body, a feat achieved by three other countries until now, would be a great technological achievement for the spatial ambitions of Isro and India.
It would pave the way for future Indian missions to land on Mars and an asteroid. More importantly, it would open the possibility for India to send astronauts to the Moon. India hopes to carry out a manned space flight by 2022.
India also wants to affirm itself as a space power to take into account, and national pride is on the rise, since it aims to raise its flag on the surface of the Moon.
A successful mission to the Moon would also be a victory for India's ambitious space agency, which has had a series of successes recently.
In 2014, he successfully put a satellite into orbit around Mars, becoming the fourth nation to do so. In 2017, India created the story by successfully launching 104 satellites in a single mission, surpassing the previous record of 37 satellites released by Russia in 2014.
All eyes are on Isro again. According to Simonetta Di Pippo, director of the UN Office of the United Nations Affairs Office of the Outer Space of the UN, the global interest in the frugal mission of the Moon in India is at its height.
"Mission studies on lunar topography, mineralogy, elemental abundance, lunar exosphere and hydroxyl signatures and water ice will contribute to the scientific progress of all mankind," she says.
The Indian space community is nervous and Dr. Sivan says that "there is agitation in his stomach".
"The unknown-unknown can kill a mission, [although] no stone has been left unturned to understand all the complexities. "
How long is the trip to the moon?
The launch is just the beginning of a journey of 384,000 km (239,000 miles): the robot ship is expected to land on the Moon some 54 days later, on September 6 or 7.
Isro chose a tortuous route to take advantage of the gravity of the Earth, which will help launch the satellite towards the Moon. India does not have a rocket powerful enough to launch Chandrayaan-2 on a direct path.
"There will be 15 scary minutes for the scientists once the lander is launched and it launches towards the south pole of the Moon," says Dr. Sivan.
Explain that those who had been controlling the ship until then will have no role to play at these crucial times. The real landing, he adds, is an autonomous operation that depends on all systems working as they should. Otherwise, the lander could collide with the lunar surface.
Earlier this year, the first mission of the Moon in Israel crashed while trying to land.
Who is on the team?
About 1,000 engineers and scientists have worked on this mission. But for the first time, Isro has chosen women to lead an interplanetary expedition.
Two women are directing the trip from India to the Moon. While the program's director, Muthaya Vanitha, has fed Chandrayaan-2 over the years, she will be navigated by Ritu Karidhal.
"The power of women is driving the Moon's ambitions in India," said Dr. Sivan, adding that in Isro "women and men are all the same, only talent matters, not gender."
Report of Pallava Bagla, who has written extensively on the Indian space program.