Chandrayaan-3 Vikram Lander's Controlled Hop Experiment on the Moon

Key Facts

• Chandrayaan-3 Vikram lander conducted a controlled hop in September 2023 on the lunar surface.
• The lander fired its throttleable liquid engines on command, elevating approximately 40 cm above the Moon's surface.
• It soft-landed about 30–40 cm away from its original landing spot without damage to its operational systems.
• The hop was an additional experiment beyond the mission's primary objectives.
• Instruments on board, including ChaSTE and ILSA, were retracted before the hop and redeployed after.
• Data from ChaSTE showed a two-layer structure of lunar regolith, with about 3 cm of loose dust cleared by engine plume revealing a denser layer beneath.
• Vikram lander and Pragyan rover landed near the Moon's south polar region in August 2023.

Background & Context

Chandrayaan-3 is India's lunar mission aiming to demonstrate safe and soft landing, rover deployment, and in-situ scientific experiments on the Moon. Following a successful soft landing near the lunar south pole in August 2023, the Vikram lander conducted this controlled hop experiment to validate technology that may enable ascent, repositioning, or sample return in future missions. The ability to lift-off and land again is a key technology milestone for human and robotic lunar exploration missions.

Why This Matters for Exams / Exam Relevance

This experiment highlights India’s indigenous advancement in space technology, specifically for lunar surface operations including mobility and ascent capabilities. Understanding such technological demonstrations is important in subjects related to space science, technology, and India's space achievements. It further provides insights into lunar geology through regolith studies and showcases capabilities critical for future sample return missions and human exploration.

Points to Remember

• The hop experiment was not part of the original Chandrayaan-3 mission plan but served as an additional demonstration.
• The lander's propulsion system includes throttleable 800N mono-propellant liquid engines capable of powered ascent and controlled descent.
• ChaSTE (Chandra’s Surface Thermophysical Experiment) measures thermal properties and helped identify regolith layering.
• ILSA (Instrument for Lunar Seismic Activity) measures seismic activity on the lunar surface.
• The uppermost 3 cm of loose lunar dust was cleared during the hop, exposing a denser subsurface layer of regolith.
• These findings aid in understanding lunar surface conditions critical for safety, mobility, and sample collection.
• The Vikram lander weighs approximately 1752 kg including the rover.
• The mission design life was about one lunar day (~14 Earth days), and rover Pragyan covered over 100 meters before entering sleep mode.