ISRO faced and continues to face several significant challenges in the Chandrayaan-3 mission, particularly related to the lunar environment and the complexities of a soft landing:
- Soft Landing Complexity : The most critical challenge was achieving a soft landing on the Moon's surface. This involved transitioning the spacecraft from a horizontal orbit to a vertical descent, which is a complex maneuver requiring precise control of orientation and thrust to avoid crashes
- Navigation and Guidance : Chandrayaan-3 had to autonomously manage its navigation and guidance due to communication delays with Earth, making real-time control impossible. Advanced sensors and cameras, including a Laser Altimeter and Lander Hazard Detection and Avoidance Camera (LHDAC), were used to ensure the lander stayed on the correct trajectory and landed at the designated site
- Vertical Descent Control : Controlling the descent speed and position in the Moon's low gravity environment required sophisticated dynamic and control algorithms. Variable thrust engines were precisely controlled to counteract the Moon's gravity and ensure a smooth landing
- Limited Real-time Earth Control : Due to the large distance from Earth, the lander had to operate autonomously during critical landing phases, which added complexity to the mission
- Hostile Lunar Environment : After landing, the spacecraft faces challenges such as extreme temperature variations (from +120°C to -150°C), high radiation levels from the Sun and cosmic rays, and constant micrometeoroid impacts, all of which can damage the lander and rover systems
- Precision Landing : The landing site was a small, carefully selected patch near the lunar south pole, requiring extremely precise landing to avoid hazards and ensure mission success
- Limited Operational Timeline : The mission was designed to operate primarily during the lunar day (about 14 Earth days), after which the lander and rover enter a dormant state due to the harsh lunar night, limiting the duration of active exploration
These challenges reflect the complexity of lunar missions and the advancements ISRO had to achieve to ensure Chandrayaan-3's success, especially learning from the setbacks of Chandrayaan-2
