Japan’s SLIM ‘moon sniper’ reaches lunar orbit ahead of landmark landing

CONTEXT: Japan will attempt to become just the fifth country in the world to soft-land a spacecraft on the Moon.

• The Japan Aerospace Exploration Agency (JAXA) announced the successful insertion of its "Smart Lander for Investigating Moon" (SLIM) into lunar orbit at 1:21 PM IST.
• SLIM's elliptical lunar orbit connects the Moon's south and north poles with a period of about 6.4 hours.
• The altitude ranges from about 600 kilometers at the closest point to the Moon (perilune) to 4,000 kilometers at the furthest point (apolune).
• JAXA plans to lower the apolune point until mid-January 2024, and the perilune point will be lowered to an altitude of 15 kilometers on January 19.
• The descent towards the Moon is set to begin on January 20, with the mission aiming for a soft landing.
• SLIM, also known as the "Moon sniper," is on a uniquely long route to the Moon and is the second Japanese mission targeting a soft landing.
• Weighing just 200 kilograms, SLIM is designed to demonstrate precision landing capabilities, aiming to land within 100 meters of the chosen site.
• This mission is critical for ensuring spacecraft can land close to scientifically interesting sites on the Moon, accessible by a rover.
• SLIM's objective includes landing near a small crater named Shinoli in the Moon's equatorial region.
• If successful, SLIM will be the smallest and lightest spacecraft to land on the Moon, marking Japan's entry into the list of countries achieving soft landings on the lunar surface.
• The Chandrayaan-3 lander, by comparison, weighed about 1,750 kilograms.

The Japan Aerospace Exploration Agency (JAXA)

It is Japan's national agency for air and space activities, established through the amalgamation of three distinct organizations on October 1, 2003. JAXA holds responsibilities for satellite research, technology advancement, and satellite launches into orbit. Additionally, it engages in ambitious missions like exploring asteroids and contemplating human exploration of the Moon. The agency operates under the motto "One JAXA" and follows the corporate slogan "Explore to Realize," formerly known as "Reaching for the skies, exploring space."

Chandrayaan-3

The Chandrayaan-3 program marks India's third lunar mission and second endeavor to achieve a gentle landing on the moon's  surface. Launched from the Satish Dhawan Space Centre in Sriharikota on July 14, 2023, the spacecraft successfully entered lunar orbit on August 5, 2023, with a historic moment occurring on August 23, 2023, when the lander achieved a successful touchdown near the lunar south pole.

Mission Objectives:

• Demonstrate a safe and soft landing on the lunar surface.
• Showcase rover mobility on the moon.
• Conduct in-situ scientific experiments.

Components:

Chandrayaan-3 comprises three modules:

• Propulsion Module: Responsible for carrying the lander and rover configuration to a 100 km lunar orbit. This module features the Spectro-polarimetry of Habitable Planet Earth (SHAPE) payload for studying Earth's spectral and polarimetric measurements from the lunar orbit.
• Lander Module (Vikram): Carries a scientific payload with instruments such as Chandra’s Surface Thermophysical Experiment (ChaSTE) for measuring thermal conductivity and temperature, Instrument for Lunar Seismic Activity (ILSA) for assessing seismicity, and Langmuir Probe (LP) for estimating plasma density variations. Additionally, a passive Laser Retroreflector Array from NASA is included for lunar laser ranging studies.
• Rover Module (Pragyan): Equipped with instruments like Alpha Particle X-ray Spectrometer (APXS) and Laser Induced Breakdown Spectroscopy (LIBS) to analyze the lunar surface and subsurface composition near the landing site.