Chandrayaan-3 Launcher Upper Stage Uncontrollably Re-Enters Earth Atmosphere

The Indian Space Research Organisation (ISRO) announced the uncontrolled re-entry of the cryogenic upper stage of the LVM-3-M4 launch vehicle, responsible for successfully placing the Chandrayaan-3 spacecraft into orbit on July 14 this year. The re-entry, occurring within 124 days of launch, adhered to the "25-year rule" for low-Earth orbit objects, in accordance with guidelines from the Inter-Agency Space Debris Coordination Committee (IADC), as confirmed by ISRO.

ISRO stated that the probable impact area was expected to be over the North Pacific Ocean, and the final trajectory avoided crossing over India, according to their released statement.

The rocket component, part of the LVM-3-M4 launch vehicle, re-entered Earth atmosphere at approximately 14:42 IST. Post-Chandrayaan-3 injection, the upper stage underwent "passivation" to eliminate any remaining propellant and energy sources, aligning with space debris mitigation guidelines from the United Nations and IADC.

In a statement, ISRO emphasized that the passivation and post-mission disposal of the rocket body, in compliance with internationally accepted guidelines, underscored India commitment to preserving the long-term sustainability of outer space activities.

Chandrayaan-3, India third lunar mission, aimed for a soft landing on the moon surface for the second time. Departing from the Satish Dhawan Space Centre in Sriharikota on July 14, 2023, the spacecraft smoothly entered lunar orbit by August 5, 2023. The historic moment occurred when the lander flawlessly touched down near the lunar south pole on August 23, 2023.

Key Objectives of Chandrayaan-3:

• Demonstrate a safe and soft landing on the lunar surface: This is a critical objective for Chandrayaan-3, as its predecessor, Chandrayaan-2, failed to land successfully. The Chandrayaan-3 lander is designed to use a combination of sensors and algorithms to achieve a precise and controlled landing.
• Demonstrate rover roving on the moon: Once the lander has successfully touched down on the lunar surface, it will deploy a rover named Pragyan. Pragyan will explore the moon surface and conduct a series of scientific experiments.
• Conduct in-situ scientific experiments: Pragyan will be equipped with a suite of scientific instruments that will allow it to study the moon geology, atmosphere, and environment. These experiments will help us to better understand the moon past and present, and to prepare for future lunar exploration.

Significant Discoveries of Chandrayaan-3:

• Presence of Sulfur on the Lunar Surface: The Pragyan rover Laser-Induced Breakdown Spectroscope (LIBS) instrument has confirmed the presence of sulfur on the lunar surface near the south pole. Sulfur is a volatile element that is not generally expected to be found on the Moon, so this discovery is a major surprise. The presence of sulfur could have implications for our understanding of the Moon formation and evolution.

• Warm Temperatures at the Lunar South Pole: Chandrayaan-3 data has shown that the temperatures at the Moon south pole are significantly warmer than previously thought. The temperatures are too warm for water ice to be stable, which suggests that any water ice that may be present is likely to be buried deep beneath the surface.
• Composition of Lunar Soil: The Pragyan rover has analyzed the composition of the lunar soil at the landing site. The soil is found to be rich in iron, calcium, and aluminum, with traces of other elements such as silicon, magnesium, and titanium. This data is helping scientists to better understand the geological history of the Moon.
• Detection of Lunar Earthquakes: Chandrayaan-3 seismic sensors have detected several lunar earthquakes, providing evidence of ongoing geological activity on the Moon. These earthquakes are likely caused by the movement of tectonic plates deep within the Moon interior.
• Confirmation of Ejecta Distribution: Chandrayaan-3 has confirmed the distribution of ejecta, or material that was ejected during the impact that formed the South Pole- Aitken Basin (SPA). This data is helping scientists to better understand the impact history of the Moon. These are just a few of the significant discoveries that Chandrayaan-3 has made since its arrival on the Moon. The mission is expected to continue to make important contributions to our understanding of the Moon for many years to come.