India cemented its place as a major international power in the space sector when its Chandrayaan-3 mission landed successfully near the Moon’s south pole, where attempted landings by several countries have failed earlier due to its rugged terrain, craters and deep trenches
Indian Space Research Organisation (ISRO) created history on Wednesday when its Moon mission Chandrayaan-3 successfully landed on the south lunar pole, a highly challenging terrain because of deep trenches, lack of wide and flat surface.

Particularly, at the backdrop of the failure during the Chandrayaan-2 mission in respect of conducting the soft-landing of the Lander unit on the lunar surface, this achievement is highly praiseworthy. With this success now, India becomes the first country in the world to land near the Moon’s south pole.

Chandrayaan-3 mission was launched on July 14, 2023 and undertook a few weeks of travel to reach lunar orbit. Finally, after around 40 days of effort, the Lander unit with a rover in its belly safely landed on the Moon.

Challenges of soft landing

A soft landing on the Moon's south pole is a very tricky task. ISRO was not able to do that with precision during 2019. Also, during the last four years, two private agencies, one from Israel and another form Japan did attempt to undertake a soft-landing of their robotic equipment on the Moon, but unfortunately both these missions failed.

All this indicates how challenging such missions are. ISRO’s earlier Chandrayaan-2 mission had two segments: An orbiter and a lander and rover system. This mission was partially successful since ISRO was able to put the orbiter in the correct orbit. Today, the same orbiter is getting used for two-way communication for the Chandrayaan-3 mission.

Obviously, there was a good amount of savings and the mission cost is around Rs 600 crores. This India’s third mission to the Moon was launched with two main modules: a Propulsion Module and a lander & rover unit (lunar module).

The lunar module was connected to the Propulsion Module and both got separated after 34 days (Aug 17). The Propulsion Module was the energy source for this mission to travel to a distance of around 3.8 lakh km.

Subsequently, the Lander Module used its own power source to undertake a precise landing on the lunar surface. The rover unit which is now already out of the lander’s belly is expected to depend on solar energy for its operations. The rover is expected to work for 14-days (one lunar day) and undertake various observations.

The structure of the lunar module is almost similar to that of the Chandrayaan-2 mission. The earlier mission’s total mass was 3,877 kg (orbiter plus lunar module). While the weight of Chandrayaan-3 was approximately 18 kg more.

Robust lander

The absence of an orbiter allowed ISRO to make the lander more robust. Based on the experience of the last mission ISRO had decided to have the lander with strong legs. The Chandrayaan-3 lander weighs 252 kg more than the earlier mission.

The nature of payloads (sensors for undertaking observations and doing experimentation) was almost the same as that of the last mission. The lander comes with three payloads, while the rover has two. The instruments on the lander are now undertaking measurements for understanding the thermal properties of the lunar surface at its location.

Advance sensor

There is a sensor to measure seismicity near the landing site and to outline the structure of the lunar crust and mantle below the surface. The Langmuir Probe is for the measurement of the near surface plasma density and its changes with time.

Measurement of the key plasma parameters like electron temperature, ion density, and electron energy distribution function would help to know about the gaseous structure, density fluctuations, or molecular absorption.

The propulsion module has a single sensor for studying the Spectro-Polarimetric signatures of the Earth in near-infrared wavelengths. It is important to note that the propulsion module after separation was expected to work for three to six months.

But, since ISRO is able to undertake the mission in a copybook fashion, hence there is a good amount of fuel savings. Hence, now the propulsion module is known to remain healthy for one year.

Hard work of ISRO scientists

To make this mission successful, ISRO scientists had worked really hard for almost four years. A very detailed analysis of the reasons for the failure of the second mission was carried out.

Based on that, some important changes in software and hardware were carried out. Various simulations were undertaken by ISRO to identify the possibilities of what could go wrong. Based on these inputs the software algorithms were strengthened.

Failure of Russia’s Luna-25 Moon mission

During the second week of August 2023, the Russian space agency Roscosmos launched the Luna-25 robotic Moon mission with a lander and rover unit. It was the first mission by Russia since 1976 and this mission was also expected to land on the south pole of the Moon.

This mission was happening, when India’s Chandrayaan-3 was in progress. There was some talk about the so-called space race between India and Russia. Unfortunately, this mission failed. This was an interesting mission and its rover was to operate for one year on the lunar surface. The loss of this mission should be viewed as a loss to science.


In fact, India’s Chandrayaan-2 mission was to happen during 2015 as a joint mission with Russia. However, owing to some issues with their space sector, Russia was not able to participate in this joint venture.

It was just a coincidence that Chandrayaan-3 and Luna-25 happened during the same time. The talk of the so-called space race was totally uncalled for.

ISRO is going to the Moon for multiple reasons, like finding the water on the Moon and looking for minerals. Chandrayaan-3 mission is expected to provide some relevant inputs to ISRO in that direction.

There is a possibility that ISRO would undertake Chandrayaan-4 mission as a joint mission with Japan. It could be said that, with successful soft-landing on the lunar surface, ISRO has reached an important landmark in its space quest since the 1960s.

***The writer is a consultant at MP-IDSA, New Delhi; views expressed here are his own