By Girish Linganna
Russia’s first moon landing attempt since the 1970s failed on Sunday (August 20, 2023) as the Luna-25 lander crashed into the lunar surface after losing contact with Earth controls, said Russia’s space agency, Roscosmos. Launched on August 11, Luna-25 was in a race with India to become the world’s first mission to land in the lunar south pole region. But India now has the opportunity to place the first probe near the lunar south pole with its Chandrayaan-3 mission, launched on July 14, 2023.
The Luna-25 lander had successfully negotiated entry into the Moon’s orbit on Wednesday (August 16, 2023) last week with a touchdown on the lunar surface scheduled for Monday. However, at 2.10 pm (Moscow time) on Saturday, an ‘emergency situation’ cropped up while the engine was being fired to enter an orbit that would set it up for a lunar landing and the lander’s communication links with Earth station snapped.
Roscosmos reported on Sunday (August 20, 2023) that all reconnection attempts had failed and Luna-25 collided with the Moon’s surface after straying from its intended orbit. Roscosmos said an inter-agency commission would be set up to probe the likely reasons for the failure.
Chandrayaan-3, ISRO’s highly ambitious mission, is in its final phase. The Indian spacecraft aims to achieve a gentle touchdown on the Moon’s surface after a similar attempt by Chandrayaan-2 on September 7, 2019. It has chosen a lengthier—but more fuel-conserving—route to the Moon and its landing is scheduled for Wednesday (August 23, 2023).
A successful Chandrayaan-3 mission would position India as the fourth nation to achieve the feat of softly landing a robotic lunar rover on the Moon’s surface, following the US, China and the erstwhile Soviet Union. The mission, launched as a follow-up to Chandrayaan-2, aims to showcase the full process of safe landing and rover movement on the lunar surface.
On August 17, the Indian spacecraft had effectively detached the Lander Module, housing the Vikram lander and Pragyan rover, from the Propulsion Module. It successfully adjusted its orbit to 113 km x 157 km on August 18, through effective deboosting after launch on July 14. Deboosting the Lander Module of the Chandrayaan-3 spacecraft involved reducing its speed to reach an orbit where the spacecraft’s closest and farthest points to the Moon were just a few kilometres away. This manoeuvre aimed to facilitate a gentle landing on the lunar surface.
Chandrayaan-3 successfully underwent its second round of deboosting where the orbit of the Lander Module was reduced, the Indian Space Research Organisation (ISRO) said on Sunday. But, although this operation has brought the spacecraft closer to the Moon, it still has to undergo internal checks, ISRO added.
Achieving a soft lunar landing involves slowing down from a speed of 6,000 km/hour to a complete stop. Following the current phase, the Vikram lander will adjust itself to a 90-degree angle to ensure a safe landing on the Moon’s surface. At approximately 100 metres above the surface, the lander will assess potential obstacles. If no issues are detected, it will slowly descend, utilizing its thrusters for controlled movement until it touches down.
India is poised to set a new record with a soft landing on the Moon’s southern polar region. So far, soft landings have been accomplished exclusively in the Moon’s equatorial zone by the US, China and Russia. Lunar missions have historically focused on the equator due to its favourable topography and operational circumstances. The southern polar area of the Moon poses distinct challenges owing to its markedly different terrain. India has chosen to explore the Moon’s southern pole due to its larger expanse in comparison with the northern pole. The presence of water is a potential consideration in the perpetually shaded zones around this region.
The lunar South Pole experiences unique conditions, where the Sun remains close to the horizon, leading to temperatures surpassing 54°C during periods of sunlight. Despite the illumination, certain craters contain permanently shadowed areas that have remained devoid of sunlight for billions of years, causing temperatures to plummet to as low as -203°C.
Despite employing sophisticated sensors, discerning the lunar south pole’s terrain and appearance will be challenging for a descending vehicle due to the interplay of landscape and lighting conditions. The extreme and contrasting conditions found on the lunar south pole present difficulties for humans. Yet, they also hold the promise of containing valuable insights into the early solar system.
It has been a month and a week since ISRO initiated the Chandrayaan-3 mission on July 14. The name, Chandrayaan, means ‘Moon Vehicle’ in Sanskrit. It was launched from Sriharikota’s Satish Dhawan Space Centre in Andhra Pradesh. The budget is officially put at only Rs. 250 crore though launch vehicle expenses are not included in it.
Chandrayaan-3 accommodates a Propulsion Module with a 2-metre-tall lander and a rover, weighing roughly 3,900 kg. The lander’s purpose is to deploy the rover onto the lunar surface with a mission duration of one lunar day equivalent to 14 earth days
Many government space initiatives and private organizations across the world are intrigued by this area of the Moon, as they believe it may contain water ice that could prove invaluable for future astronauts. From Chandrayaan-3 to the Luna-25 mission and NASA’s Artemis II, lunar exploration has consistently captivated space scientists for centuries. What drives the strong interest of major powers in the Moon?
Positioned 384,400 km (238,855 miles) away from Earth, the Moon plays a role in stabilizing Earth’s axial wobble, contributing to a more consistent climate, while also generating oceanic tides. Back in 2008, the Indian mission Chandrayaan-1 made the groundbreaking revelation of the presence of water on the Moon. This discovery highlighted hydroxyl molecules scattered across the lunar surface, particularly concentrated at the poles. Water is essential for sustaining human life and can serve as a valuable reservoir of hydrogen and oxygen, which, in turn, can be utilized as propellant for rockets
Helium-3, an uncommon helium isotope on Earth, holds the potential for nuclear energy generation in fusion reactors. On the Moon, NASA indicates, there might be around a million tons of this isotope. Unlike radioactive materials, Helium-3 would not yield hazardous waste, as noted by the European Space Agency.
The Moon contains valuable rare earth metals, such as scandium, yttrium and the 15 lanthanides. These elements are essential components in smart-phones, computers and advanced technologies, Boeing’s research unit points out. (IPA Service)
(The author is a Defence, Aerospace analyst based in Bengaluru)