Overview
NASA selected the lunar South Pole region as the location for its Moon Base because of the area’s unique scientific value and potential to support long-term exploration. But many of the characteristics that make this region so valuable also make it an extraordinarily challenging place to live and work. Extreme and highly variable temperatures, abrasive lunar dust, rugged terrain, and difficult lighting conditions all present major challenges for sustained surface operations.
Establishing an enduring human presence in this environment will require more than simply adapting systems and operations designed for shorter missions. NASA and its partners will need to develop resilient technologies and infrastructure, carefully plan where and how surface assets are placed and operated, and learn how to keep equipment functioning safely and reliably over longer periods on the lunar surface.
Extreme Temperatures and Lighting
The lunar South Pole has a dramatically different lighting and thermal environment than the equatorial regions explored during Apollo. Near the pole, the Sun remains low on the horizon, producing long shadows that move across the rugged terrain. Depending on a location’s elevation and surrounding topography, some areas can receive extended periods of sunlight, while craters and other low-lying terrain may remain in shadow for long periods—or, in permanently shadowed regions, never receive sunlight at all.
Those lighting conditions are closely tied to the region’s extreme temperatures. With essentially no atmosphere to redistribute heat, temperatures on the lunar surface depend heavily on how much solar energy a location receives. Some permanently shadowed regions near the South Pole can reach temperatures as low as about minus 334°F (minus 203°C), while nearby sunlit areas can be much warmer. The exact thermal environment varies considerably with factors including Sun angle, latitude, elevation, and terrain.
For systems expected to operate on the Moon for long periods, surviving these conditions is a significant engineering challenge. Extended darkness can deprive solar-powered systems of energy at the same time that extreme cold increases the power needed to keep critical components within survivable temperatures. Electronics, batteries, joints, and other hardware can all be affected by prolonged exposure to low temperatures.
Thermal control also requires balancing competing needs. During cold periods, systems must limit heat loss and may require heaters and insulation to remain within operating or survival limits. When conditions are warmer, those same systems must be able to reject excess heat. Designing hardware that can manage both conditions—and transition between them repeatedly—is an important consideration for long-duration lunar operations.
Lighting and thermal conditions will influence where and how Moon Base systems are placed and operated. Site planning must account for terrain-driven patterns of sunlight and shadow, access to solar power, and the ability of systems to survive periods without sunlight. As infrastructure is added over time, planners will also need to consider shadows cast by habitats, power systems, and other structures and how those shadows could affect nearby operations and solar power generation.
Rugged Terrain
The lunar South Pole is a rugged, heavily cratered landscape marked by steep slopes, ridges, deep craters, and dramatic changes in elevation. While Apollo astronauts also explored challenging terrain, all six Apollo landing sites were located at lower latitudes, where the Sun rose higher above the horizon. Near the South Pole, rugged topography combines with low-angle sunlight and long shadows to create a uniquely challenging environment for landing, navigating, and operating on the surface.
Terrain will influence nearly every aspect of establishing and operating a Moon Base. Spacecraft need sufficiently safe and accessible areas to land. Habitats, power systems, communications equipment, and other infrastructure must be placed where the ground and surrounding terrain can support their operations. Even relatively small robotic systems must navigate slopes, rocks, craters, and other obstacles as they move equipment, conduct science, survey potential sites, or scout routes for future missions.
The terrain can also make some of the Moon’s most scientifically and potentially resource-rich locations difficult to reach. Deep craters near the South Pole contain permanently shadowed regions that may preserve water ice and other volatile materials. Exploring these areas could require astronauts and robotic systems to navigate steep slopes, uneven ground, deep shadow, and extreme temperatures to collect samples and characterize resources that could one day support in-situ resource utilization.
As Moon Base grows, understanding the terrain in greater detail will help NASA determine not just where to explore, but where and how to build. High-resolution mapping, robotic reconnaissance, autonomous navigation, and increasingly capable surface systems will help identify safe landing and operating areas, characterize potential infrastructure sites, plan routes across the surface, and expand access to more challenging terrain.
Lunar Dust
Lunar dust is one of the most persistent challenges of exploring and operating on the Moon. The Moon’s surface is covered in regolith—a layer of broken rock, mineral fragments, glass, and fine dust shaped over billions of years by meteorite and micrometeorite impacts and exposure to the space environment. Unlike soil on Earth, lunar material is not weathered by wind or water. Many of its particles are irregular and abrasive, and the finest dust can work its way into small openings in equipment and surface systems.
The Apollo missions provided our only firsthand experience with how lunar dust affects astronauts and equipment on the Moon—and showed just how difficult the problem can be. Dust clung to spacesuits, coated equipment, and was tracked inside the lunar modules after astronauts returned from the surface. Apollo 17 astronaut Gene Cernan even described dust as “one of our greatest inhibitors to a nominal operation on the Moon.” During these missions, astronauts spent only a relatively short time on the lunar surface. Future exploration will require systems to withstand repeated exposure while operating for much longer periods, making dust mitigation increasingly important as humans spend more time on the lunar surface.
Dust is easily disturbed. Astronauts walking across the surface, rover wheels, excavation activities, and spacecraft landings can all send regolith particles moving across the lunar environment. Once disturbed, the dust can coat spacesuits, visors, solar arrays, radiators, seals, mechanisms, and other exposed surfaces.
The properties of lunar dust make it especially difficult to manage. Particles can become electrically charged and cling to surfaces, while freshly exposed particle surfaces may also be chemically reactive. Abrasive dust can wear spacesuit materials and moving parts; particles that enter bearings, gears, and seals can increase friction, accelerate wear, or interfere with their operation. Dust accumulation can also obscure optical surfaces and reduce the performance of systems such as radiators and solar arrays.
Keeping dust outside crewed spaces will be another important challenge. Apollo astronauts inadvertently carried lunar dust into their spacecraft after surface excursions, and some reported irritation after inhaling it. Future crews could encounter lunar dust repeatedly over much longer missions, making limiting exposure and controlling dust inside habitats an important consideration for sustained exploration.
There is no single solution to the lunar dust problem. Dust mitigation involves a combination of three approaches: avoid, remove, and tolerate. That can mean designing surface assets and operations to reduce how much dust is disturbed, protecting vulnerable components from exposure, developing surfaces and technologies that shed or remove dust, filtering particles from crewed environments, and building resilient systems that can continue functioning despite some contamination.
The Moon was formed ~4.5 billion years ago, about 30-50 million years after the origin of the Solar System.
Near the Moon’s South Pole, the Sun stays low on the horizon, creating rare areas that can remain sunlit for long periods of time —offering operational benefits, including milder temperatures, reduced duration of lunar nights, and persistent availability of solar power.
Some surfaces near the lunar South Pole may be more than 3.85 billion years old — older than any site visited by Apollo astronauts.
The Moon’s South Pole-Aitken Basin is the largest known impact crater in the solar system, stretching more than 1,550 miles (2,500 km) wide — about the distance from Waco, Texas, to Washington, D.C.
Shackleton Crater is more than twice as deep as the Grand Canyon. Its permanently shadowed interior is believed to contain ice, making it a leading target for future lunar exploration.
As part of the Moon Base, NASA is advancing radioisotope heating demonstrations to help protect surface assets during cold lunar nights and operations in permanently shadowed regions.
Lunar regolith may one day help sustain life on the Moon. Researchers are studying how lunar soil might be used to build habitats, grow crops, and produce oxygen for astronauts as well as liquid oxygen for rocket propellant.
