Chandrayan - 3 Launch

Chandrayaan-3 (transl.?"mooncraft";^[6][7] pronunciation (help·info)) is the third lunar exploration mission by the Indian Space Research Organisation (ISRO).^[8] It consists of a lander and the Pragyan rover similar to Chandrayaan-2, but does not have an orbiter. Its propulsion module behaves like a communication relay satellite. The propulsion module carries the lander and rover configuration until the spacecraft is in a 100 km lunar orbit.^[9][10]

Following Chandrayaan-2, where a last-minute software glitch in the soft landing guidance software led to the failure of the lander's soft landing attempt after a successful orbital insertion, another lunar mission was proposed.^[11]

The launch of Chandrayaan-3 took place at July 14, 2023, at 2:35 pm IST^[12] and injection of 100 km circular polar orbit is completed successfully as part of phase one.^[2][13]The lander and rover is expected to land near the lunar south pole region on August 23, 2023.^[14]

Chandrayaan-3 comprises three main components

Propulsion Module

The propulsion module will carry the lander and rover configuration till 100 km lunar orbit. It is a box-like structure with one large solar panel mounted on one side and a large cylinder on top (the Intermodular Adapter Cone) that acts as a mounting structure for the lander. In addition to the lander, the module carries a payload called Spectro-polarimetry of Habitable Planet Earth (SHAPE) to study the spectral and polarimetric measurements of Earth from the lunar orbit.^[10][9]

Lander

The lander is responsible for the soft landing on the Moon. It is also box-shaped, with four landing legs and four landing thrusters of 800 newtons each. It will carry the rover and various scientific instruments to perform in-site analysis.

The lander for Chandrayaan-3 will have only four throttle-able engines,^[21] unlike Vikram on Chandrayaan-2 which had five 800 Newtons engines with a fifth one being centrally mounted with a fixed thrust. Additionally, the Chandrayaan-3 lander will be equipped with a Laser Doppler Velocimeter (LDV).^[22] The impact legs are made stronger compared to Chandrayaan-2 and increased instrumentation redundancy. ISRO is working on improving the structural rigidity and adding multiple contingency systems.^[23]

The lander will carry three payloads:

• Chandra's Surface Thermophysical Experiment (ChaSTE) will measure the thermal conductivity and temperature of the lunar surface.
• Instrument for Lunar Seismic Activity (ILSA) will measure the seismicity around the landing site.
• Langmuir Probe (LP) will estimate the plasma density and its variations.

Rover

Chandrayaan-3 Rover Overview:

• Six-wheeled design
• Weight of 26 kilograms (57 pounds)
• Range of 500 meters (1,640 feet)
• Scientific instruments including cameras, spectrometers, and a drill
• Expected lifespan of one lunar day (14 Earth days)
• Communication with the lander and ground control team in India

The Chandrayaan-3 Rover is expected to make a number of important scientific discoveries, including:

• The composition of the lunar surface   
• The presence of water ice in the lunar soil
• The history of lunar impacts
• The evolution of the Moon’s atmosphere

The Chandrayaan-3 Rover is a major step forward for India’s space program. It is a testament to the country’s growing technological capabilities, and it is sure to make significant contributions to our understanding of the Moon.