Chandrayaan-3’s ChaSTE: Pioneering Lunar Thermal Research

This article from The Hindu, dated April 2, 2025, details the success of the Chandra’s Surface Thermophysical Experiment (ChaSTE) aboard Chandrayaan-3, marking India’s first successful thermal probe deployment on a celestial body. It underscores ISRO’s technological prowess and scientific contributions to lunar exploration, offering valuable insights into space technology and planetary science for aspirants preparing for competitive exams.

Key Points

• Chandrayaan-3 Landing: The Vikram lander of Chandrayaan-3 successfully landed on the Moon on August 23, 2023, near the lunar south pole.
• ChaSTE Deployment: Post-landing, the ChaSTE thermal probe, stowed in Vikram’s panels, was deployed using motors to penetrate the lunar soil.
• First Successful Probe: ChaSTE became the first instrument to measure in-situ temperatures near the Moon’s south pole, overcoming challenges faced by previous missions.
• Probe Design: Equipped with 10 temperature sensors spaced 1 cm apart along its length, ChaSTE reached a depth of 10 cm into the lunar soil.
• Operational Period: It collected temperature data from August 24 to September 2, 2023, during the Chandrayaan-3 mission.
• Mechanism: A rotation-based deployment pushed the probe into the soil, with sensors detecting surface contact and resistance to confirm depth.
• Scientific Milestone: Data revealed higher-than-expected water ice prevalence on the Moon, enhancing understanding of lunar resources.
• Comparison with Past Missions: Unlike the European Space Agency’s Philae lander (2014) and NASA’s InSight (2018), which struggled with soil penetration, ChaSTE succeeded due to its rotating mechanism.
• Philae’s Failure: The Philae lander’s MUPUS instrument, intended to measure comet 67P’s temperature, failed to penetrate beyond a few centimeters after bouncing twice on landing in 2014.
• InSight’s Struggle: NASA’s HP3 instrument on Mars, designed to dig 35 cm, only reached a shallow depth due to low friction, with sensors on a tether failing to collect data.
• ChaSTE’s Innovation: Principal investigator Durga Prasad K. from the Physical Research Laboratory, Ahmedabad, highlighted the rotating device as key to ChaSTE’s success.
• Temperature Findings: The probe recorded a peak surface temperature of 355 K (±0.5 K), higher than the predicted 330 K (±3 K), indicating significant spatial variability at high latitudes.
• Implications: These findings are crucial for future lunar exploration, suggesting thermal considerations for habitat design and mission planning.

Glossary

• Chandrayaan-3: India’s third lunar mission, achieving a soft landing near the Moon’s south pole in 2023.
• ChaSTE: Chandra’s Surface Thermophysical Experiment, a thermal probe measuring lunar soil temperature and properties.
• Vikram Lander: The landing module of Chandrayaan-3 that deployed the ChaSTE probe and Pragyan rover.
• Lunar South Pole: A region near the Moon’s southern extremity, targeted for its potential water ice deposits.
• In-Situ Measurement: Direct data collection at the site, as performed by ChaSTE on the lunar surface.
• Thermal Probe: An instrument designed to measure temperature and thermal conductivity in soil.
• Water Ice: Frozen water detected in lunar soil, vital for future exploration and habitation.
• ISRO: Indian Space Research Organisation, the agency behind Chandrayaan-3’s success.
• Regolith: The loose, fragmented material covering the Moon’s surface, studied by ChaSTE.
• Spatial Variability: Differences in temperature and properties across small distances, observed at high lunar latitudes.

Link To The Original Article – https://www.thehindu.com/sci-tech/science/chandrayaan-3-chaste-instrument-first-successful-thermal-probe-celestial-body/article69403476.ece