Ignore - if not interested in nerdy science - Trying to give some scientific insights in answering the questions:
(Comments are scientifically accurate -- figures etc are not 'official' etc)
hanumadu wrote: ↑23 Aug 2023 23:03
CNN (not IBN but the Amrikan wala channel) had this ex NASA astronaut and professor in their studios to talk about Indian moon landing and he
was saying that no one attempted to land on the south pole so far because no body thought it was feasible. But in 2019 we almost did it and that should have made it clear it was possible but other than Russia nobody attempted to do it in 4 years.
China landed on the dark side of the moon. How difficult was it compared to ours and how did/do they communicate with it?
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Wrt to "dark site"
Dark site is not really a dark site .. sun light (and night) for 14 days. Yet China's successful soft landing on the far side of the Moon was a significant achievement and a complex engineering feat. The Chang'e 4 mission, which included both a lander and a rover, touched down in the Von Kármán crater within the South Pole-Aitken Basin on the lunar far side. This mission marked the first time a spacecraft had successfully soft-landed on the far side of the Moon.
Compared to missions that landed on the near side of the Moon, landing on the far side presents several additional challenges:
Communication Challenges:
One of the primary difficulties in landing on the far side of the Moon is that direct communication with Earth is blocked by the Moon itself. To overcome this challenge, China utilized a relay satellite named Queqiao, positioned at the Earth-Moon Lagrange Point 2 (L2), which provides a line of sight to both the far side of the Moon and Earth. This relay satellite receives signals from the lander and rover and then relays them to Earth.
Precise Navigation and Timing:
The lack of direct line of sight to Earth makes real-time navigation and control more challenging. The spacecraft must rely on preprogrammed instructions and automated systems for much of the landing process, as immediate intervention from Earth is not possible.
Landing Site Selection:
Identifying a suitable landing site on the far side of the Moon requires careful consideration of topography, lighting conditions, and surface properties. The Chang'e 4 mission's landing site within the Von Kármán crater was carefully chosen to minimize risks and provide scientific value.
In general -- these issues are in the 'near side too but still Terrain and Illumination:
The far side of the Moon has rough and cratered terrain, and lighting conditions can be challenging due to long shadows and uneven illumination. These factors require advanced autonomous landing and navigation systems.
Power Management:
Lunar days and nights are each about two weeks long, which requires spacecraft to manage their power generation and storage systems to survive the extreme temperature variations.
Communication Latency:
Due to the signal travel time between the relay satellite and Earth, there is a communication delay. This delay means that real-time control from mission control on Earth is not possible during critical moments, such as landing.
China's approach to addressing these challenges involved careful mission planning, advanced communication technologies, autonomous navigation systems, and well-designed scientific instrumentation. The success of the Chang'e 4 mission demonstrated China's growing capabilities in space exploration and engineering.
Overall, landing on the far side of the Moon is significantly more complex than landing on the near side due to the communication challenges posed by the Moon's position relative to Earth. Successful missions, like Chang'e 4, require careful coordination and technological innovation to ensure safe landings and mission success.
---- Now coming to south polar reason: Challenges are:
Topography and Terrain:
The lunar South Pole region is characterized by rugged terrain, deep craters, and uneven surfaces. The area is also prone to having shadowed and permanently shadowed regions where sunlight might not reach. This makes it challenging to find a flat and safe landing site for a spacecraft.
Extreme Temperatures:
The South Pole region experiences extreme temperature variations. Lunar day and night cycles are about 14 Earth days long each, resulting in extremely hot daytime temperatures and frigid nighttime temperatures. The temperature extremes can impact the performance of spacecraft components and materials.
Communication and Line of Sight:
The South Pole region can pose challenges for communication with Earth due to the curvature of the Moon and the positioning of communication satellites. Spacecraft on the far side of the Moon might have limited or no direct line of sight with Earth, which can impact real-time control and data transmission. (CH2 and CH3 PM which are, (per my calculation) about 160 degree apart helps)
Harsh Lighting Conditions:
The South Pole region has unique lighting conditions due to the angle of the Sun's illumination. Shadows in the cratered terrain can be long and deep, making it difficult to determine the exact shape of the landscape. This can complicate landing site selection and navigation.
Unknown Surface Properties:
The South Pole region might have different soil properties and surface materials compared to other regions of the Moon. Unknown factors about the surface's strength and composition can make it challenging to predict how spacecraft will interact with the surface upon landing.
Dust and Regolith Challenges may be more pronounced ( don't know much about the region)
Lunar dust and regolith can pose challenges during landing and operations. The fine, abrasive dust can get into mechanical systems and obscure sensors, potentially affecting the spacecraft's functionality.
--The rugged and cratered terrain of the South Pole region can lack distinct visual landmarks that spacecraft often rely on for navigation and orientation.
-- Lunar days and nights are relatively long, making it important for any spacecraft sent to the South Pole region to be able to withstand extended periods of darkness, low temperatures, and potential power challenges during lunar nights. (CH3 has nor RTG(
Addressing these challenges requires careful mission planning, advanced navigation systems, reliable communication infrastructure, robust thermal control measures, and adaptable landing technologies. Despite these challenges, the South Pole region is of great interest to scientists and space agencies due to its potential water
ice resources, which could be critical for future lunar exploration and establishing a sustainable human presence on the Moon
(Hope this is useful)