In January 2024, Japan is set to make a significant leap in space exploration with its attempt to land the Smart Lander for Investigating Moon (SLIM) spacecraft on the lunar surface. This endeavor marks a pivotal moment as Japan aims to become the third country to achieve a soft moon landing in the 21st century, following China and India. This historic mission, if successful, will witness Japan’s first-ever spacecraft landing on the moon.
SLIM, a mission orchestrated by the Japan Aerospace Exploration Agency (JAXA), was launched on September 7, 2023, from the Tanegashima spaceport. The spacecraft is relatively lightweight, weighing only 590 kg, compared to India’s Chandrayaan-3, which weighed 3,900 kg at launch. This difference in mass is primarily due to SLIM carrying less fuel. The trajectory taken by SLIM to reach the moon is also distinct, following a more fuel-efficient route based on weak-stability boundary theory, as opposed to the Hohmann transfer orbit used by Chandrayaan-3.
The SLIM mission is notable for its high precision in targeting its landing site. The spacecraft aims to land within 100 meters of its chosen site, setting a new standard for accuracy in moon landings. SLIM will deploy two small rovers, Lunar Excursion Vehicle (LEV) 1 and 2, to study the lunar surface near the landing point, collect temperature and radiation readings, and attempt to study the moon’s mantle.
Japan’s moon-landing attempt has implications for India’s upcoming Chandrayaan-4 mission. Chandrayaan-4, also known as the Lunar Polar Exploration (LUPEX) mission, is a joint Indian-Japanese project set to launch in 2026. This mission will explore an area closer to the moon’s south pole than Chandrayaan-3 did, and the technologies tested by JAXA with SLIM, such as the feature-matching algorithm and navigation systems, will be crucial for the success of Chandrayaan-4. For this mission, JAXA is expected to provide the launch vehicle and the lunar rover, while India will provide the lander module.
The success or failure of SLIM will not only impact Japan’s standing in space exploration but will also influence the collaborative efforts and technological approaches in the upcoming Chandrayaan-4 mission. This synergy between Japanese and Indian space missions underscores the growing importance of international collaboration in advancing lunar exploration and the broader goals of space science