Chandrayaan-5, also referred to as the LUPEX (Lunar Polar Exploration) mission, is the fifth mission in India’s Chandrayaan series of lunar missions. It is a joint mission of ISRO and JAXA aimed at studying lunar volatile materials, including lunar water, in the vicinity of a Permanently Shadowed Region (PSR) near the lunar south pole. The mission has emerged as an important symbol of India-Japan cooperation in space exploration.
On 29 August 2025, during the India-Japan Summit, Prime Minister Narendra Modi welcomed the collaboration between ISRO and JAXA for the Chandrayaan-5 mission. He described the mission as a symbol of mankind’s progress in space and stated that Japanese technology and Indian ingenuity form a strong combination. The Implementing Arrangement for LUPEX was exchanged between JAXA Vice President Matsuura Mayumi and Indian Ambassador Sibi George, giving practical shape to the partnership. The mission was discussed during the 15th India-Japan Annual Summit, where both sides exchanged agreements to deepen cooperation in advanced technology, mobility and space research.
The core objective of Chandrayaan-5 / LUPEX is to explore the resource-rich lunar south pole, especially the permanently shadowed regions, and study hidden lunar resources, particularly water ice and other volatile materials. The mission is intended to generate knowledge about the quantity and quality of lunar water resources and the principles governing their concentration. This is important for assessing the potential use of such resources in future sustainable space exploration activities.
The mission focuses on the less-explored lunar south pole, where permanently shadowed regions are believed to contain valuable volatile deposits, including water ice. The importance of water on the Moon lies in its future utility. Water can be split through electrolysis to produce oxygen and hydrogen, which can serve as rocket fuel. If available in sufficient quantity, it can become a major resource for future crewed lunar missions, reducing the need to carry large quantities of fuel from Earth.
Chandrayaan-5 / LUPEX follows the legacy of Chandrayaan-1, Chandrayaan-2, and Chandrayaan-3, while being placed after the forthcoming Chandrayaan-4, which is described as India’s first lunar sample return mission. LUPEX is presented as one of the major short-term milestones in India’s long-term lunar roadmap. It is also described as a precursor to ISRO’s lunar sample return mission and to the larger vision of sending the first Indian to the Moon by 2040.
According to the input, the Government of India approved the Chandrayaan-5 / LUPEX mission on March 10, 2025 in the form of a financial sanction. Thereafter, ISRO and JAXA intensified mission planning and technical coordination. On May 13–14, 2025, the two sides held the third face-to-face Technical Interface Meeting (TIM-3) at ISRO Headquarters, Bengaluru. This meeting included senior officials, project executives, and technical teams from ISRO, JAXA, and Mitsubishi Heavy Industries (MHI), Japan. The discussions covered technical interfaces, the joint mission implementation plan, and the potential landing sites.
A Japanese delegation later visited ISRO and held discussions with the senior leadership of the organisation. On November 21, 2025, Saku Tsuneta, Vice-Chair of Japan’s Cabinet Committee on National Space Policy, met ISRO Chairman V. Narayanan to review the status of the Chandrayaan-5 / LUPEX mission and discuss future opportunities. The delegation also visited technical facilities at the ISRO Satellite Integration and Test Establishment (ISITE) of the U.R. Rao Satellite Centre (URSC). Discussions also extended to future cooperation in areas such as robotic arm technology for space stations, launching scientific satellites, and support for researchers and private companies of both countries.
The mission will be launched by JAXA onboard its H3-24L launch vehicle. The mission articles specifically note that the launch will take place on Japan’s H3 rocket, which is Japan’s new mainstay launch vehicle. The H3 is described as a three-stage rocket, about 63 metres tall, with a mass of about 574 tonnes, and powered by a combination of solid fuels and cryogenic propellants such as liquid hydrogen and liquid oxygen. It will be launched from the Tanegashima Space Center (TNSC) in Japan.
Under the LUPEX arrangement, ISRO will provide the lunar lander, while JAXA will provide the rover. The rover is identified in one source as the MHI, Japan-made lunar rover. ISRO is also responsible for developing a few scientific instruments for the mission. The scientific payloads will be contributed by ISRO, JAXA, ESA, and NASA, with all instruments thematically connected to the exploration and in-situ analysis of volatiles in the lunar polar region. This makes LUPEX not only a bilateral mission, but also one with wider international scientific participation.
According to the input, the Japanese rover is expected to have a mass of about 350 kg, making it about 10 times heavier than the 25 kg Pragyan rover used in Chandrayaan-3. The overall LUPEX spacecraft is said to weigh approximately 6,500 kg. The rover dimensions are stated as about 2.0 m long, 1.8 m wide, and 3.3 m tall. It will move autonomously on the lunar surface to search for areas likely to contain water, and it will collect subsurface samples using a drill. Observation equipment mounted on the rover will then analyse these samples in detail.
The scientific emphasis of Chandrayaan-5 / LUPEX is on direct in-situ investigation of polar volatiles. The mission aims to determine whether water ice exists in the target region, how it is distributed, and in what quantity and form it occurs. The rover will directly measure the water content of lunar material through on-site analysis, which is a major advance over remote-sensing-only approaches. The mission is therefore designed to provide basic data on the usability of lunar water resources for future exploration.
During the joint technical meetings, special attention was given to landing site selection, payload optimisation, mission design, and the ground segment and communication aspects of the mission. The landing target is associated with a Permanently Shadowed Region in the lunar south pole, where prior remote-sensing observations indicate a high probability of the presence of water ice and other volatiles.
As per the input, the mission is expected to operate for a little over 100 days after lunar landing, with the possibility of surviving for up to one year. This gives the mission a relatively long surface exploration window for in-situ scientific work in the polar environment.
The LUPEX mission has significance beyond robotic exploration. It is directly linked to India’s longer-term ambitions for crewed lunar exploration. The mission is described as a precursor to future lunar sample return efforts and eventually to the goal of Indian astronauts landing on the Moon by 2040. It is also said to contribute foundational knowledge useful for international programmes like the Artemis Programme, especially in the context of long-term human presence on the Moon.
The input mentions that M. Ganesh Pillai, Scientific Secretary to ISRO, congratulated both teams for their technical achievements and stressed the importance of the collaborative effort. Tirtha Pratim Das, Director of the ISRO Science Programme Office, explained the milestones achieved in landing site selection, payload optimisation, mission design, ground segment, and communication aspects. Ravi Chandra Babu, study team leader of Chandrayaan-5 / LUPEX, highlighted the need for a clear definition of milestones, timeline, and deliverables. On the Japanese side, Dai-Asoh of JAXA briefed participants on the technical progress made in rover development and related mission interfaces.
Chandrayaan-5 / LUPEX is a major India-Japan lunar mission focused on the exploration of lunar water and polar volatiles near the Moon’s south pole. It combines ISRO’s lunar lander capability with JAXA’s rover technology and includes scientific contributions from multiple international agencies. The mission is important not only for understanding the Moon’s hidden resources, but also for advancing the long-term goal of sustainable lunar exploration and future human missions to the Moon.