ISRO releases images of the far side area of the moon

ISRO releases images of the far side area of the moon

Subject :Science and technology

Section: Space technology

Context:

• The images were captured on August 19 by the Lander Hazard Detection and Avoidance Camera (LHDAC) which is onboard the Lander.

Details:

• ISRO has already released three videos of the moon captured by its third moon mission Chandrayaan-3.
• One of them was taken by the Lander Position Detection Camera (LPDC) on August 15, 2023.
• Another one taken by the Lander Imager (LI) Camera-1 just after the separation of the Lander Module from the Propulsion Module.

Far side of the moon:

• The far side of the Moon is the lunar hemisphere that always faces away from Earth, opposite to the near side, because of synchronous rotation in the Moon’s orbit.
• Compared to the near side, the far side’s terrain is rugged, with a multitude of impact craters and relatively few flat and dark lunar maria (“seas”), giving it an appearance closer to other barren places in the Solar System such as Mercury and Callisto.
• It has one of the largest craters in the Solar System, the South Pole–Aitken basin.
• The hemisphere has sometimes been called the “dark side of the Moon”, where “dark” means “unknown” instead of “lacking sunlight” – each side of the Moon experiences two weeks of sunlight while the opposite side experiences two weeks of night.
• About 18 percent of the far side is occasionally visible from Earth due to libration.
• The remaining 82 percent remained unobserved until 1959, when it was photographed by the Soviet Luna 3 space probe.
• The Soviet Academy of Sciences published the first atlasof the far side in 1960.
• The Apollo 8 astronauts were the first humans to see the far side in person when they orbited the Moon in 1968.
• All crewed and uncrewed soft landings had taken place on the near side of the Moon, until 3 January 2019 when the Chang’e 4 spacecraft made the first landing on the far side.
• Astronomers have suggested installing a large radio telescope on the far side, where the Moon would shield it from possible radio interference from Earth.

Lander Hazard Detection and Avoidance Camera (LHDAC):

• This camera that assists in locating a safe landing area — without boulders or deep trenches — during the descent is developed by ISRO at SAC.
• LHDAC enables terrain mapping, hazard detection and safe sites designation in real time during landing maneuvers.

About Chandrayaan-3:

• Chandrayaan-3 is a follow-on mission to Chandrayaan-2 to demonstrate end-to-end capability in safe landing and roving on the lunar surface.
• It consists of Lander and Rover configuration.
• It will be launched by LVM3 from SDSC SHAR, Sriharikota.
• The propulsion module will carry the lander and rover configuration till 100 km lunar orbit.
• The propulsion module has Spectro-polarimetry of Habitable Planet Earth (SHAPE) payload to study the spectral and Polari metric measurements of Earth from the lunar orbit.

The mission objectives of Chandrayaan-3 are:

• To demonstrate Safe and Soft Landing on Lunar Surface
• To demonstrate Rover roving on the moon and
• To conduct in-situ scientific experiments.

To achieve the mission objectives, several advanced technologies are present in Lander such as:

1. Altimeters: Laser & RF based Altimeters
2. Velocimeters: Laser Doppler Velocimeter & Lander Horizontal Velocity Camera
3. Inertial Measurement: Laser Gyro based Inertial referencing and Accelerometer package
4. Propulsion System: 800N Throttleable Liquid Engines, 58N attitude thrusters & Throttleable Engine Control Electronics
5. Navigation, Guidance & Control (NGC): Powered Descent Trajectory design and associate software elements
6. Hazard Detection and Avoidance: Lander Hazard Detection & Avoidance Camera and Processing Algorithm
7. Landing Leg Mechanism.