India is looking to make history on Wednesday with its third lunar mission set to land on the Moon.
If Chandrayaan-3 is successful, India will be the first country to land near the Moon's little-explored south pole.
One of its major goals is to hunt for water-based ice, which scientists say could support human habitation on the Moon in future. India's attempt comes just days after Russia's Luna-25 crashed while trying to touch down in the same region.
If successful, it will also be only the fourth country to achieve a soft landing on the Moon – the US, the former Soviet Union and China have all landed near the equator. India's attempt to land its Chandrayaan-2 mission near the south pole in 2019 was unsuccessful – it crashed into the lunar surface. So all eyes are now on Chandrayaan-3.
The spacecraft with an orbiter, lander and a rover lifted off on 14 July from the Sriharikota space centre in south India. The lander – called Vikram after Indian Space Research Organisation (Isro) founder Vikram Sarabhai – carries within its belly the 26kg rover named Pragyaan, the Sanskrit word for wisdom.
Its journey to the Moon has generated a lot of excitement in India, with wishes for the mission's success pouring in from across the country.
Isro has announced plans for a live telecast of the landing and millions of people, including schoolchildren, are expected to tune in. Isro chief Sreedhara Panicker Somanath has said he is confident that Chandrayaan-3 will make a successful soft landing.
He said they had carefully studied the data from the Chandrayaan-2 crash and carried out simulation exercises to fix the glitches.
In the past few days, the Vikram lander's camera has been extensively mapping the lunar surface while attempting to locate a safe landing spot. In its update on Tuesday, Isro said the mission “is on schedule, systems are undergoing regular checks and smooth sailing is continuing”.
Mr Somanath has said Chandrayaan-3 will work to build on the success of India's earlier Moon missions and help make some “very substantial” scientific discovery. Chandrayaan-1, the country's first Moon mission in 2008, had discovered the presence of water molecules on the parched lunar surface and established that the Moon has an atmosphere during daytime.
And despite failing the soft landing, Chandrayaan-2 was not a complete write-off – its orbiter continues to circle the Moon even today and will help the Vikram lander send images and data to Earth for analysis.
The lander and the rover are carrying five scientific instruments which will help discover “the physical characteristics of the surface of the Moon, the atmosphere close to the surface and the tectonic activity to study what goes on below the surface”.
On Wednesday, scientists will use a complex set of manoeuvres to reduce the lander's speed gradually to bring it to a point which will allow a soft landing in an area which space scientists have described as “very uneven, full of craters and boulders”.
Once it lands and the dust settles, the six-wheeled rover will crawl out of its belly and roam around the rocks and craters on the Moon's surface, gathering crucial data and images to be sent to the lander, which will pass it on to the orbiter to send to Earth.
The rover's wheels have the Isro's logo and emblem embossed on them so that they leave imprints on the lunar soil during the Moon walk, an official told the BBC.
The landing date has been carefully selected to coincide with the start of a lunar day (a day on the Moon equals 14 days on Earth) because the batteries of the lander and the rover will need sunlight to be able to charge and function. Once night falls, they will discharge and stop working. It's not yet clear whether they will come back to life when the next lunar day starts.
The south pole of the Moon holds special promise in that search – the surface area that remains in permanent shadow there is huge, and scientists say it means there is a possibility of water in these areas.
India is not the only country with an eye on the Moon – there's a growing global interest in it, with many other missions headed to the lunar surface in the near future. And scientists say there is still much to understand about the Moon, which is often described as a gateway to deep space.
A successful Chandrayaan-3, they say, will take us a step closer in that quest.
— CutC by bbc.com
