Explained: How India and Japan will execute Chandrayaan-5/LUPEX Moon mission

Till date, India has completed three lunar missions in the Chandrayaan (moon vehicle) series. Now the Indian Space agency ISRO is working on Chandrayaan-4, a mission to land on the moon, collect lunar samples and bring them back to the home planet. Meanwhile, the Indian Government has also approved the Chandrayaan-5 mission, which will be jointly conducted by the Indian Space Research Organization(ISRO) and the Japan Aerospace Exploration Agency(JAXA). This marks the first Indo-Japan collaborative effort in space exploration. Over the last few years, this Indo-Japan moon mission has been referred to as LUPEX - Lunar Polar Exploration Mission. However, the Indian government now refers to it as Chandrayaan-5.

"After Chandrayaan-3's successful lunar soft-landing, the first near the south pole, all nations began believing in India's capability and Japan's JAXA wanted a collaborative mission. The launch of this Chandrayaan-5/LUPEX mission will be carried out by a Japanese rocket, ISRO will build the lunar lander, while Japan will build the rover. This mission will feature a 350kg lunar rover, which is 10 times heavier than the 25kg Indian 'Pragyan' rover that was deployed as part of Chandrayaan-3," ISRO Chairman Dr. V. Narayanan told WION's Sidharth.M.P.

He added that the mission is meant to explore water and resource availability near the lunar south pole and quantify their availability. "Configuration studies for CHandrayaan-5/LUPEX have been completed, design teams are being formed and it'll be accomplished in three years."

According to JAXA, the H3 Launch Vehicle is Japan's new mainstay rocket. The three-stage vehicle stands 63meters tall and weighs 574tons. The rocket is powered by solid-fuels and cryogenic fuels (Liquid hydrogen and liquid oxygen). The H3 is built to reduce launch price by utilizing commercial-off-the-shelf products of other domestic industries such as the automobile industry rather than products exclusive to space use. Instead of following the build-to-order production approach, the industries follow something similar to the line production system which is used for general industrial products. 

The H3 rocket carrying the LUPEX mission will be launched from the Tanegashima Space Center (TNSC), the largest rocket-launch complex in Japan with a total area of about 9,700,000 square meters. The facility is located in the south of Kagoshima Prefecture, along the southeast coast of Tanegashima, it is widely regarded as the most beautiful rocket-launch complex in the world.

LUPEX’s objective is to collect data on the quantity and quality of water resources and its concentration principles in order to determine the extent lunar water resources can be used for future sustainable space exploration activities. The overall LUPEX craft would weigh 6,500kg approximately, and this includes a 350kg  rover that measures 2.0m long, 1.8 wide and 3.3 tall. The rover being developed by JAXA will drive on its own to search for areas where water is likely to be present and sample the soil by digging into the ground with a drill. The plan is to acquire data by analyzing the collected samples in detail with observation equipment mounted on the rover. The mission is expected to live a little over 100days after the lunar landing, and it could live for a maximum of one year, as per JAXA.

Water can be electrolyzed(split) to produce rocket fuel (oxygen and hydrogen). If there is enough water, it will be an important resource for future crewed space activities because it will eliminate the need to transport large quantities of fuel from the earth. For this reason, not only Japan but also space agencies around the world are now planning to investigate water (ice)resources in the polar regions of the Moon. LUPEX will land in an area where past remote sensing observations indicate the high possibility of existence of water (ice) . LUPEX rover will directly measure the water content by in-situ observation. In addition, by observing the distribution and existence of water resources and quantifying its amount, LUPEX will collect the basic data on the potential use of water resources and contribute to the Artemis Program, a proposed US-led effort to return astronauts to the moon and enable their long-term presence.  

According to JAXA, LUPEX will be carrying a total of 10 scientific payloads. These includes five payloads from JAXA, three payloads from ISRO, and one payloads each from the NASA and the European Space Agency. 

The payloads are Resource Investigating Water Analyzer (REIWA), Lunar Thermogravimetric Analyzer (LTGA), Triple-reflection Reflectron (TRITON), Aquatic Detector using Optical Resonance (ADORE), International Symposium of Antennas and Propagation (ISAP), Advanced Lunar Imaging Spectrometer (ALIS), Neutron Spectrometer, Ground Penetrating Radar, Exospheric Mass Spectrometer for LUPEX (EMS-L), Mid-Infrared Imaging Spectrometer (MIR).