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ISRO identifies site for Chandrayaan-4 lander

February 09, 2026 4 min read Science & Technology GS Paper 3
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What Happened

  • ISRO has identified a specific landing site designated MM-4 in the Mons Mouton region near the lunar south pole for the Chandrayaan-4 mission.
  • Scientists used high-resolution imagery from the Chandrayaan-2 orbiter's Terrain Mapping Camera to evaluate four candidate sites (MM-1, MM-3, MM-4, and MM-5) based on slope angle, elevation, hazard density, and number of safe landing grids.
  • MM-4 was selected because it has a minimal hazard percentage within a 1 km x 1 km area, an average slope of approximately 5 degrees, a mean elevation of 5,334 metres, and the highest number (568) of safe landing grids, with an overall risk level calculated at 9.89%.
  • The site is located at 84.289 degrees south latitude and 32.808 degrees east longitude.
  • Chandrayaan-4, approved by the Union Cabinet in September 2024 with a budget of Rs 2,104.06 crore, is planned for launch around 2028 and aims to return up to 3 kg of lunar regolith to Earth.

Static Topic Bridges

India's Chandrayaan Programme

The Chandrayaan programme is India's series of lunar exploration missions, with "Chandrayaan" meaning "mooncraft" in Sanskrit. The programme has progressively advanced India's capabilities in deep space exploration.

  • Chandrayaan-1 (2008): India's first lunar probe, launched on PSLV-C11 from Sriharikota. It carried NASA's Moon Mineralogy Mapper (M3) instrument, which confirmed the presence of water molecules on the lunar surface. India became the fifth national space agency to reach the Moon.
  • Chandrayaan-2 (2019): Launched on GSLV Mk III (LVM3). The Vikram lander crashed during its descent due to a software glitch, but the orbiter continues to operate and has provided high-resolution imagery used in site selection for subsequent missions.
  • Chandrayaan-3 (2023): Successfully soft-landed near the lunar south pole on 23 August 2023, making India the fourth country to achieve a soft landing on the Moon and the first to land near the south polar region. The Pragyan rover detected sulphur, aluminium, and calcium on the surface.
  • Chandrayaan-4 (planned 2028): India's first lunar sample return mission, with five modules launched on two LVM3 rockets, requiring orbital docking before proceeding to the Moon.

Connection to this news: The identification of the MM-4 landing site marks a concrete step in Chandrayaan-4's mission planning, building directly on the high-resolution terrain data collected by the Chandrayaan-2 orbiter that has been operational since 2019.

Lunar Sample Return Missions

Lunar sample return missions involve collecting material from the Moon's surface and safely transporting it back to Earth for detailed laboratory analysis. Only three entities have previously achieved this: the United States (Apollo programme, 1969-1972, approximately 382 kg), the Soviet Union (Luna programme, 1970-1976, approximately 301 grams), and China (Chang'e 5 in 2020, 1.731 kg from the near side; Chang'e 6 in 2024, approximately 1.9 kg from the far side).

  • Sample return requires mastery of multiple technologies: precision landing, surface sample collection (drilling or scooping), autonomous ascent from the lunar surface, orbital rendezvous and docking, and high-speed re-entry into Earth's atmosphere.
  • Chandrayaan-4 will use a five-module architecture: Transfer Module, Propulsion Module, Descender Module (lander), Ascender Module (for lifting samples off the Moon), and Re-entry Module (for returning samples to Earth).
  • The two-launch architecture is necessitated by the mass constraints of the LVM3 rocket. The modules will dock in Earth orbit before proceeding to the Moon.
  • ISRO is developing robotic arms for sample collection and a high-capacity propulsion system specifically for this mission.

Connection to this news: The selection of MM-4 at Mons Mouton is critical because the lander must touch down on terrain flat enough and hazard-free enough to safely deploy robotic arms for sample collection and to allow the Ascender Module to lift off from the surface.

Significance of the Lunar South Pole

The lunar south pole is a region of intense scientific and strategic interest for space agencies worldwide. Unlike the equatorial regions explored by earlier missions, the poles contain permanently shadowed craters that may harbour water ice and other volatile compounds preserved for billions of years.

  • Water ice at the poles could serve as a resource for future human habitation: drinking water, oxygen generation via electrolysis, and hydrogen fuel production.
  • The Chandrayaan-3 ChaSTE (Chandra's Surface Thermophysical Experiment) instrument found that slope orientation and sun exposure affect water ice stability, indicating subsurface ice deposits near the poles.
  • Multiple nations are targeting the south pole: NASA's Artemis programme, China's ILRS (International Lunar Research Station), and the European Space Agency's Argonaut lander.
  • Mons Mouton is a highland plateau near the south pole, offering relatively flat terrain at high latitude, which balances scientific value (proximity to potential ice deposits) with landing safety.

Connection to this news: ISRO's choice of Mons Mouton at 84.289 degrees south latitude places Chandrayaan-4 among the southernmost landing attempts on the Moon, maximising the scientific value of returned samples that may contain clues about water ice distribution and lunar geological history.

Key Facts & Data

  • Chandrayaan-4 budget: Rs 2,104.06 crore (approximately USD 250 million), approved September 2024
  • Target launch: 2028, with 36-month completion timeline from approval
  • Sample return target: up to 3 kg of lunar regolith
  • Landing site MM-4 coordinates: 84.289 degrees S, 32.808 degrees E
  • MM-4 specifications: average slope 5 degrees, mean elevation 5,334 m, 568 safe landing grids, 9.89% risk level
  • Launch vehicles: two LVM3 (formerly GSLV Mk III) rockets
  • Five modules: Transfer Module, Propulsion Module, Descender, Ascender, Re-entry Module
  • Only three entities have previously returned lunar samples: USA (Apollo), USSR (Luna), and China (Chang'e 5 and 6)
  • Chandrayaan-2 orbiter (operational since 2019) provided terrain mapping data used for site selection