Will Russian Luna 25 beat Chandrayaan-3 to land first on the South Pole of the Moon?

Russia is resuming its Moon agenda. On 11 Aug 2023, the Russian space agency Roscosmos is expected to launch the Luna-25 robotic mission with a lander and rover unit to the Moon. It would be the first mission by Russia since 1976. Obviously, since this mission is going to happen when another mission to the Moon, India’s Chandrayaan-3 is in progress, some comparisons are inevitable. Every mission to the Moon, be it in the past or in progress or futuristic, would have its own agenda and scientific goals. Every mission should be viewed based on the technological and financial capabilities of the agency undertaking the said mission and unnecessary comparisons should be avoided. But, at the same time, even some inexact assessments could be of some help to decide on the future trajectory for furthering the interests of specific programs.

It would be interesting to check ISRO’s Chandrayaan-3 mission’s strengths and limitations in comparison with some of the recent Moon programs by other states.

Chandrayaan-3 is India’s indigenous Moon program. India started its Moon agenda with the successful launch of Chandrayaan-1 in 2008, which was an orbiter mission. During this mission, ISRO put a satellite in the vicinity of the Moon, which operated for almost one year. Based on the data received during this mission, ISRO in collaboration with NASA scientists was able to establish the fact that there is a presence of water on the Moon. This has been the greatest achievement not for India but for the overall global Moon agenda.  Chandrayaan-2 mission was launched in 2019. This mission had two parts: to put an orbiter in the vicinity of the Moon and to operate a robotic unit consisting of a lander and a rover on the surface of the moon. Unfortunately, the lander and rover unit crash-landed on the Moon’s surface. Hence, this mission was a partial success. Actually, this mission should have happened around 2015. It was supposed to be a joint mission between India and Russia and the Russians were expected to contribute to the lander and rover system. However, ISRO was required to go solo, since Russia had expressed inability to participate in the mission owing to internal problems.

Now around eight years since Russia had stated their inability to contribute to India’s Chandrayaan-2 program, they have decided to go solo and visit the Moon by undertaking a soft-landing of their robotic equipment. This Luna-25 mission is planned to operate on the lunar surface for a year as against Chandrayaan-3, which would be operating for two weeks. Luna-25 would be reaching the Moon in five days and may take another five to seven days to position itself for a Moon landing on the designated landing sites. Chandrayaan-3 is likely to attempt Moon landing on 23 Aug 2023, hence there is a likelihood that Luna-25 would land before Chandrayaan-3. Both these missions would be exploring the Moon’s South Pole and if all goes well then Luna-25 would be the first craft on land on the South Pole of the Moon. One of the most important aspects of Russia’s mission is the time it would take to reach the Moon. The distance of the Moon from the Earth is about 384,400 km. Russia would be able to reach the Moon in around ten days.

It would be of interest to check how much time various other Moon missions have taken to reach there.  Apollo 11 (July 16, 1969), the first human mission to the Moon took four days to reach the Moon. The entire mission got over in around eight days with Neil A. Armstrong and Co reaching the Moon and getting back to the Earth. Apollo 11, used a direct trajectory known as Translunar Injection to reach the Moon. The powerful Saturn V launch vehicle undertook this mission.

At present, the US space agency NASA is working on a program for the human return to the Moon, almost five decades after their earlier Apollo program, which had carried humans to the Moon. Presently, they are undertaking various tests to validate the human rating of their Orion spacecraft, testing the heat shield and other technologies. In this connection, NASA launched Artemis 1 (The Orion spacecraft), an uncrewed Moon-orbiting mission on 16 Nov 2022.

Artemis 1 mission was unlike the robotic landing mission by India or Russia. Within eighty-nine minutes after lift-off, the craft had carried out the trans-lunar injection (TLI) manoeuvre. In the case of Chandrayaan-3, on the 19th day after the launch, TLI was carried out, while the Lunar-Orbit Insertion (LOI) was carried out on the 23rd day after the launch. In the case of the US mission, on the sixth day after the launch, Orion had completed one flyby of the Moon and subsequently entered a distant retrograde orbit for six days, and completed a second flyby of the Moon on the 21st day. The Orion spacecraft returned and re-entered the Earth’s atmosphere and splashed down in the Pacific Ocean on December 11.

This mission came within roughly 128 km of the lunar surface (closest approach on December 05, 2022) and realised a maximum distance from Earth of 432,210 km. With this, the Orion broke the record for the farthest distance from Earth travelled by an Earth-returning human-rated spacecraft. The earlier record was held by the Apollo 13 mission, which is known to have reached a distance of 400,171 km.

Today, China’s Moon program is progressing very nicely and the following table provides the relevant details of their various missions. They have also taken significantly less time to reach the Moon.

However, India is not the only country, which is attempting Moon missions with less powerful launch vehicles.  Recently private agencies from Israel and Japan had (unsuccessfully) attempted soft-landing missions on the Moon’s surface. Beresheet was a robotic lunar lander mission operated by SpaceIL and Israel Aerospace Industries. It was launched on 22 February 2019. It successfully captured into an elliptical lunar orbit on 4 April 2019 but crash-landed on the Moon’s surface on 11 April 2019.  Japanese start-up space had launched an unmanned Hakuto-R Mission, which failed during the last phase and crash-landed on the Moon’s surface. It had undertaken a five-month journey to attempt a lunar landing on 25 April 2023.

For all these years, ISRO has been trying its best to undertake major missions like Moon and Mars with very limited budgetary support. ISRO scientists are found innovating to overcome financial limitations. However, technology is also an issue with ISRO. The basic limitation of ISRO’s program is that it has no capacity to carry more than 4 tons of payload to the geostationary orbit. ISRO has not been able to design and develop a powerful launch vehicle for all these years and that is the reason why India requires almost 40 days of time to reach the Moon. It is not only the distance, but ISRO is also not able to carry bigger payloads to the Moon and that restricts them from carrying more sensors to the Moon for undertaking scientific experimentation.

Also Read:

Chandrayaan-3: ISRO’s second attempt for soft-landing on Moon

Moon – laboratory for understanding the universe

Today, ISRO needs a capable vehicle for undertaking more ‘substantial’ missions to the Moon and Mars. In future, ISRO has plans to undertake a mission to Venus and establish India’s own space station. All these ambitions would require the support of a capable rocket launching system. ISRO is already working on semi-cryogenic technology, which could help them to carry more weight into space. This program and other relevant programs need more attention. This is important also for carrying heavy commutation satellites to geostationary orbits. More importantly, in the future India would not be in a position to undertake human missions to the Moon because of the launcher limitation.