8. Chandrayaan-4: India’s Strategic Leap in Lunar Sample Return

Following the historic success of Chandrayaan-3, the Indian Space Research Organisation (ISRO) has advanced its lunar roadmap by identifying a landing site for Chandrayaan-4. Approved by the Union Cabinet in September 2024 with a budget of ₹2,104.06 crore, this mission transitions India from \'landing on the Moon\' to \'returning from the Moon,\' a feat currently achieved only by the USA, Russia, and China. • Primary Mission Objective: The core goal is a Lunar Sample Return, involving the collection of approximately 2-3 kg of lunar soil (regolith) and rocks from the Moon\'s South Polar region and bringing them safely back to Earth for high-fidelity laboratory analysis. • Landing Site Selection: ISRO has zeroed in on a site near Mons Mouton in the lunar South Pole (latitudes ~84°S to 86°S). This \'low-hazard zone\' offers a slope under 10°, minimal boulders, and nearly 12 days of continuous sunlight, crucial for powering the solar-dependent lander and rover. • Mission Complexity & Architecture: To overcome lift capacity constraints of the LVM3 rocket, the mission involves two separate launches. The five constituent modules (Propulsion, Descender, Ascender, Transfer, and Re-entry) will perform a complex space docking maneuver in Earth orbit before proceeding to the Moon. • Technological Milestones: Chandrayaan-4 will demonstrate critical \'foundational technologies\' for future crewed missions, including autonomous docking/undocking, lunar surface lift-off (Ascender module), and high-speed atmospheric re-entry with a sample capsule. • Strategic Timeline: Slated for launch in 2028, the mission serves as a precursor to the Bharatiya Antariksha Station (2035) and the ultimate goal of landing an Indian on the Moon by 2040. • Scientific Significance: Returning samples from the unexplored South Pole is vital for detecting water ice and understanding the Moon\'s geological evolution, which cannot be fully achieved via in-situ (on-site) experiments alone. Key Definitions • Lunar Regolith: The layer of loose, heterogeneous superficial deposits covering solid rock on the Moon. • Docking and Undocking: The process where two separate spacecraft align and physically join (dock) or separate (undock) in orbit; a prerequisite for complex deep-space missions. • Sample Return Mission: A mission designed to collect material from a celestial body and return it to Earth for study. Constitutional & Legal Provisions • Article 51-A (h): Part of Fundamental Duties, it mandates Indian citizens to \'develop the scientific temper, humanism and the spirit of inquiry and reform.\'• Indian Space Policy, 2023: A framework that defines the roles of ISRO (R&D focus), IN-SPACe (regulator for private sector), and NSIL (commercial arm), transitioning ISRO toward advanced exploration. • Outer Space Treaty (1967): An international treaty (ratified by India) that declares space as the \'province of all mankind\' and prohibits sovereignty claims over celestial bodies. • Liability Convention (1972): Holds the \'launching state\' (India) internationally liable for any damage caused by its space objects on Earth or in flight. UPSC Relevance • GS Paper III: Achievements of Indians in science & technology; indigenization of technology and developing new technology; Awareness in the fields of Space. • GS Paper II: Government policies and interventions for development in various sectors. • Mains Perspective: Importance of space diplomacy, indigenous docking technology as a strategic asset, and the economic potential of the \'Space Economy.\' Conclusion Chandrayaan-4 is not merely an incremental step but a transformative mission that establishes India\'s capability for end-to-end lunar operations. By mastering the art of returning from another celestial body, ISRO is setting the stage for sovereign human spaceflight and long-term lunar habitation, aligning with the \'Amrit Kaal\' vision for 2047.