India and Japan are advancing work on the Lunar Polar Exploration mission, known as LUPEX, as preparations continue for a planned launch later this decade.
The mission is a collaboration between the Indian Space Research Organisation and the Japan Aerospace Exploration Agency, with the NASA contributing a scientific payload. LUPEX will target the Moon’s south polar region, where scientists believe water ice may exist beneath the surface.
Officials familiar with the programme said recent engagements have focused on mission design alignment, hardware integration, and launch planning. In March, engineers from both countries met in Bengaluru for a three day technical review, concluding with a joint preliminary design sign off.
This followed earlier discussions in Japan in late 2025, where teams from both agencies and industry partners worked on interface requirements for the lander and rover systems.
Preparations have also moved to the ground. Teams from ISRO visited the Tanegashima Space Center to review launch infrastructure, indicating progress towards the execution phase.
Under current plans, ISRO will develop the lunar lander, building on experience from the Chandrayaan-3 mission. JAXA will develop the rover and is expected to provide the launch vehicle.
The rover is being designed to operate in the Moon’s uneven and cratered terrain near the south pole. Early test models show a mobility system capable of navigating slopes and rocky surfaces.
Among the key instruments is Japan’s Water Resource Analysis Instrument, or REIWA, which has undergone component testing. NASA is contributing the Neutron Spectrometer System, designed to detect hydrogen beneath the lunar surface.
Unlike earlier missions that relied primarily on orbital data, LUPEX will conduct measurements directly on the ground. The Neutron Spectrometer System analyses neutron interactions with lunar soil, with variations in signals indicating the possible presence of hydrogen.
Scientists believe water ice may exist below the surface in permanently shadowed regions near the south pole.
Understanding the distribution and quantity of water is considered important for future missions. Water could support life systems and be used to produce fuel, reducing the need to transport resources from Earth.
India and Japan have both expanded their lunar capabilities in recent years, through the Chandrayaan programme and Japan’s SLIM mission.
Beyond LUPEX, the two countries are also exploring cooperation in satellite technology, navigation systems, and Earth observation. Discussions have also begun on more complex goals, including robotic resource extraction and future human missions.
LUPEX remains a robotic mission, but one aimed at gathering data relevant to long term lunar exploration.