Characterizing visual challenges for astronauts at the Lunar South Pole

Characterizing visual challenges for astronauts at the Lunar South Pole
by Clarence Oxford
Los Angeles CA (SPX) Dec 27, 2024

NASA is preparing to send humans back to the Moon with the Artemis program, aiming to establish a long-term presence on the lunar surface. The Lunar South Pole (LSP) has been chosen for its continuous line-of-sight communication with Earth, extended solar exposure, and proximity to vital resources like water ice. However, the unique environment of the South Pole presents significant challenges, particularly concerning lighting and visibility.

Unlike previous lunar missions, the Sun at the LSP remains low on the horizon, peaking at a mere 7 elevation. This constant low-angle illumination creates harsh contrasts between bright sunlight and deep shadows. The human visual system, while highly adaptive, struggles in such environments. The combination of bright light and abrupt transitions to darkness can impair astronauts' ability to navigate hazards or perform routine tasks. NASA recognizes this as a critical engineering challenge that must be addressed to ensure mission success.

Historically, lighting and visual support for extravehicular activities (EVA) were handled at a program-specific level. In the Apollo missions, astronauts could manage sunlight exposure through careful positioning and helmet designs. However, the Artemis missions require a more comprehensive approach. The combination of direct sunlight, extended shadowing, and the need for artificial lighting demands new, integrated systems for functional vision support. These systems must allow astronauts to adapt to varying light conditions while protecting their eyes and maintaining operational efficiency.

A recent NASA assessment highlighted gaps in current requirements for functional vision. For instance, while spacesuit designs address mobility, they do not fully account for the visual demands of transitioning between bright and dark areas on the lunar surface. The report recommends integrating functional vision considerations into all aspects of design, from helmets and visors to lighting systems. Such integration is necessary to enable astronauts to safely perform tasks such as walking, operating tools, and managing equipment under challenging lighting conditions.

The assessment also emphasized the need for advanced simulation techniques. Physical and virtual simulations must be developed to evaluate helmet shields, artificial lighting, and other visual aids under realistic conditions. For example, simulations should replicate the blinding effects of sunlight and test adaptation times. Terrain-based simulations can further identify risks associated with walking and equipment operation. By leveraging the strengths of different facilities, NASA aims to validate technical solutions and enhance astronaut training.