Chandrayaan-4: How India plans to bring a piece of the moon back to earth

The moon has always fascinated humanity, and India is about to take its boldest step yet in lunar exploration. ISRO chief V. Narayanan recently announced that Chandrayaan-4, approved with a budget of Rs 2,104 crore, will launch in 2028. This is just not another moon landing this time, it will bring a piece of the moon back to the earth.

The Chandrayaan-4 mission will be unique. Imagine if one is asked to collect soil samples from a garden 384,000 kilometres away, seal them carefully, and bring them home without contamination. Now imagine doing this on the moon, where there's no air, extreme temperatures, and one cannot simply walk there. That's exactly what Chandrayaan-4 aims to achieve, making it India's most complex space mission to date.

The mission is a joint effort between ISRO and Japan's space agency JAXA, officially called the Lunar Polar Exploration Mission (LUPEX). While Chandrayaan-3 proved we could land softly on the moon, Chandrayaan-4 goes several steps further. The goal is to collect approximately 2 kilograms of moon soil and rocks from the lunar south pole and safely return them to earth for scientists to study.

But why the south pole again? “This region is special because scientists believe it contains water ice buried beneath the surface. Using detailed images from the Chandrayaan-2 orbiter and NASA's Lunar Reconnaissance Orbiter, researchers have identified a promising landing zone between 84 and 85 degrees near the south pole. This water ice isn't just scientifically interesting; it could be the key to future moon bases, providing drinking water and even rocket fuel for deeper space exploration,” explained space analyst Girish Linganna.

Chandrayaan-4 consists of five major components working together like a perfectly choreographed dance. There's a lander module that will touch down on the lunar surface, a propulsion module to power the journey, an ascender module that will lift off from the moon, a sample transfer module, and finally, a re-entry capsule that will bring the precious cargo back to earth. Each component has a specific job, and all must work flawlessly.

However, there are challenges, as Linganna points out that the entire spacecraft stack is too heavy for even India's most powerful rocket, the LVM3, which successfully carried Chandrayaan-3. “Think of it like trying to carry five heavy suitcases at once – you need more strength. ISRO's engineers solved this problem ingeniously. They are upgrading the LVM3 rocket by replacing its second stage with a more powerful SE2000 semi-cryogenic engine. This upgrade boosts the rocket's lifting capacity from 4,200 kilograms to about 5,000 kilograms,” added Linganna.

Experts point out that at the heart of the mission is a powerful lander equipped with a heavy-duty sampling system: a robotic arm, drills, collection cartridges, and an ascent system designed specifically for lunar material handling. “Unlike Chandrayaan-3, which relied on a small, mobile rover, Chandrayaan-4 introduces a new 'sampling rover mechanism' that is part of the lander itself.

Instead of moving across the surface, this new rover system performs surgical science. It is equipped with precision drilling and scooping tools that can reach below the lunar surface, identify the most scientifically valuable samples, and transfer them automatically into sealed containers. This design solves one of the biggest challenges of space: mobility is not as important as the ability to extract, preserve, and return material safely. It is less about wheels and more about intelligence,” remarked Srimathy Kesan, the founder and CEO of SpaceKidz India.

Once sealed, the samples will be loaded onto a miniature ascent vehicle that launches from the moon, performs a docking manoeuvre in lunar orbit, and hands over the samples to a return capsule headed for Earth. This contamination-free delivery exponentially increases the scientific value of the mission.

This marks a major evolution compared to the Pragyan rover of Chandrayaan-3, which, despite being a successful milestone, was limited in range and could only perform surface-level measurements. Chandrayaan-4 shifts the focus from simply observing the moon to harvesting it, returning physical evidence that can be studied for decades.

This leap matters globally. The US Lunar Roving Vehicle during Apollo gave astronauts the ability to travel several kilometres and return hundreds of kilograms of lunar rock. China, with its Yutu rovers and Chang’e series, demonstrated the power of fully autonomous sampling and robotic sample return.

“India is now integrating the best of both approaches. Chandrayaan-4 brings the mobility-inspired scientific ambition of Apollo and the precision automated engineering of China into a single concept. It isn’t a rover that drives. It’s a rover that extracts, evaluates, and returns, turning the moon into a scientific resource rather than just a destination,” added Kesan.

Chandrayaan-4’s planned landing area near Statio Shiv Shakti is one of the most scientifically valuable regions on the moon. It may contain frozen water, preserved ancient rocks, and chemical traces from the early solar system. Samples from here could answer some of the most fundamental questions of lunar science: How did the moon form? How did water arrive? Can humans survive there in the future?

A few kilograms of moon soil may sound small, but for planetary science, those samples unlock decades of high-precision laboratory work that no rover or camera can match. They allow us to study lunar geology, solar history, and the earliest phases of planetary evolution with unmatched detail.

More importantly, Chandrayaan-4 is not just scientific, it is strategic. The mission develops all the critical abilities required for future human and robotic missions: precision landing, automated sampling, ascent from the moon, docking in lunar orbit, and re-entry to earth. These are the exact technologies that nations need for lunar bases, resource mining, and long-term space exploration.

The United States showed what humans can achieve on the moon. China demonstrated the power of robotics. India is now stepping into the next chapter by combining both into a mission designed for the era of sample-return science, powered by a new rover-sampling system that is not limited by wheels.

As nations prepare for permanent lunar stations, resource extraction, and human missions, the leaders will not be the ones who simply land on the moon but the ones who can bring it back. Chandrayaan-4 marks that transition for India, transforming the moon from a place we visit into a place we can finally study, utilize, and understand.