On 14 July 2023, Chandrayaan-3 India’s third spacecraft began its 384,400-kilometre journey towards the Moon atop the medium-lift Launch Vehicle Mark-III (LVM3) rocket, positioning India as a major space power. Chandrayaan-3 Rover is a major step forward for India’s space program and a testimony of the country’s growing technological capabilities, and understanding of the Moon.
If all goes well Chandrayaan-3 will make a soft landing on the South Pole when the sun rises on the moon on either 23 or 24 August 2023. However, if due to any reason it is not possible to make the landing on these two dates, another attempt would be made to land in September.
This would make India the first country in the world to make its indigenously produced spacecraft land on the lunar South Pole and the only other country in the big-boys club after the USA, Soviet Union and China to make a controlled robotic landing on the moon.
“Chandrayaan-3 scripts a new chapter in India’s space odyssey. It soars high, elevating the dreams and ambitions of every Indian. This momentous achievement is a testament to our scientists’ relentless dedication. I salute their spirit and ingenuity!” Indian Prime Minister Narendra Modi tweeted.
To date, countries like US, Russia and China, have managed to send around 140 manned and unmanned robotic missions to the Moon but they all landed close to the Moon’s equator (the side facing the Earth), to save fuel.
Chandrayaan-3 would also be the first spacecraft to land at the lunar South Pole – a mysterious, unexplored and relatively unknown territory where no humans have ever gone before.
India was the first nation to hard land on the lunar south pole when the Moon Impact Probe (MIP), from Chandrayaan-1, was dropped near the rim of Shackleton Crater on the lunar south pole at 20:06 IST on 14 November 2008. The point impact where Chandrayaan-1 landed is called Jawahar Point. Even today, Chandrayaan-1 is remembered for being the first mission to discover moon ice.
Landing on the South Pole has always been considered a challenge because of the topography of the region where there is no sunlight for millions of years. However, at the same time, the South Pole offers immense scope for future humankind because of the likely presence of water in the form of ice.
The lunar South Pole -- the southernmost tip of the Moon has always fascinated scientists, astronomers, space enthusiasts and commoners alike because of the possibility of finding water there.
The lunar South Pole has craters on its surface that are unique in their own way, as sunlight is not able to reach their interiors. Some of these craters in the moon’s South Pole have not received sunlight for billions of years and the temperatures here could dip as low as minus 203 degrees Celsius.
This is something that ISRO always wanted to explore. This was also the reason why it decided to put its lander and rover unit of Chandrayaan-3 close to the south pole of the Moon.
The three main objectives of Chandrayaan-3 are to land safely on the surface, demonstrate rover operations and conduct scientific experiments on-site.
If all goes as planned, the Chandrayaan-3 lander will touch down in the south polar region of the moon, at a speed of under 8 kmph while the propulsion module will stay in orbit around the moon, communicating with the rover and the lander. The lunar landing is scheduled to take place on August 23 or 24, when the sun rises on the moon. This should allow Chandrayaan-3 extra working hours because a day on the Moon lasts as long as 29.5 Earth days. In other words, on the surface of the moon, it takes 29.5 days for the Sun to move all the way across the sky and return to its original position.
Another significant dissimilarity is that the moon does not have an atmosphere hence sunrise and sunset on the moon happen suddenly without any twilight. In addition, the so called ‘sky’ always looks black on the moon even during daytime when the sun is shining in the moon’s sky.
The Moon is the only natural satellite of Earth which is believed to have been formed about 4.5 billion years ago when a large amount of debris from an explosion on Earth fused together to form the Moon in space.
The Moon is a mysterious place with mountains, valleys, craters, and lava flows. There is also evidence to believe that there is a possibility of humans surviving on the Moon’s surface because of the presence of water.
These are some of the reasons why the moon has always intrigued scientists and many attempts have been made to reach the moon and look for the probability of life on its surface.
It is worth mentioning that the moon is a ready-made laboratory and the world’s largest vacuum chamber to undertake experiments for understanding the universe in general and the evolution of Earth in particular.
The erstwhile Soviet Union was the first country in the world to make a dent on the moon, literally so when Luna 2 became the first spacecraft to reach its surface and intentionally impacted the Moon on 13 September 1959. In 1966, Luna 9 became the first spacecraft to achieve a controlled soft landing, while Luna 10 became the first mission to enter orbit.
The United States took almost a decade to catch up but in the end managed to send at least nine crewed missions to Moon one after another under the Apollo program, which among others facilitated Neil Armstrong and Buzz Aldrin—became the humans to walk on the Moon. Between 1969 to 1972 as part of NASA’s Apollo program about 12 astronauts walked on the Moon. Each of these crewed missions returned safely to Earth.
Interestingly while the United States focused on the crewed Apollo program, the Soviet Union preferred to send unmanned missions that deployed rovers and returned to Earth with samples rock and soil samples from the moon.
While thereafter, many countries like India, China, US, Russia, Japan and Israel sent missions to the moon, more than 40 per cent of them failed to achieve their intended objective.
China’s Chang'e-5 collected samples weighing about 1.7 kilograms using a mechanical scoop and a drill that could burrow 2 meters underground. Chang'e-5 lander also carried a suite of cameras, ground-penetrating radar, and a spectrometer which documented the landing site mapped the subsurface and studied the mineralogical composition of the landing site to calculate the water content in the lunar soil. This allowed scientists to compare the readings on the moon with the reading of the samples back on Earth.
Chandrayaan-1 launched on October 22, 2008, was India’s first mission under the Chandrayaan program. It was a significant landmark in the country's space exploration mission. Chandrayaan-1 carried several scientific instruments, including a lunar orbiter and an impactor probe called the Moon Impact Probe (MIP). The mission successfully completed its objectives, including mapping the lunar surface and confirming the presence of water molecules on the Moon.
The second mission, Chandrayaan-2, was launched on July 22, 2019. It was a more ambitious mission that aimed to land a rover on the lunar surface. Chandrayaan-2 consisted of an orbiter, a lander called Vikram, and a rover named Pragyan. The lander and rover were intended to perform scientific experiments on the Moon's surface. However, during the landing attempt on September 7, 2019, contact with the lander was lost, and the mission did not achieve a soft landing. Despite the partial failure, the Chandrayaan-2 mission was still considered a significant achievement for India's space program.