Moon Habitats May Use Layered Mylar to Block Extreme Heat

Living on the Moon, with either trained astronauts or regular civilians, could become a regular occurrence in the near future. However, it’s easier said than done, as scientists and engineers continue developing new and advanced ways for protecting humans in the harsh lunar environment, which contrasts the mild and habitable temperatures of the Earth. The most important aspect is focusing on keeping humans alive, and this includes temperature regulation within the habitats. However, how can you maintain temperature regulation while being flexible enough to withstand physical changes like moving, handling, and compression and expansion?

Now, a team of researchers from the University of Pennsylvania might have contributed to future human missions to the Moon as they unveiled a novel design for providing insulation while delivering the flexibility for withstanding long-term use. The findings were published in ACS Applied Materials & Interfaces. The primary motivation being to fill a knowledge gap regarding how to produce and use materials capable of keeping humans alive while withstanding the long-term wear and tear of the harsh lunar environment, specifically extreme temperature changes.

To overcome this, the researchers developed layered Mylar sheets designed to withstand vacuum environments while being flexible enough for long-term use. The team evaluated Mylar thickness measured of 2.5 μm (micrometers / microns), 5 μm , and 12.5 μm along with evaluating layer density ranging between 80 to 400 layers per millimeter, with the 2.5 μm , 5 μm , and 12.5 μm stacked at 400, 200, and 80 layers, respectively. The team then subjected each layered stack to a series of rigorous tests involving vacuum conditions and a wide range of temperatures. This included subjecting the layered stacks to pressures equivalent to 200 pounds of pressure on a fingertip-sized area.

In the end, the researchers were surprised to favor the medium (5 μ"m" ) to thicker (12.5 μ"m" ) layered stacks, despite hypothesizing that the thinner (2.5 μ"m" ) layered stack. They found that the thinner layers enabled certain microparticles in the thinner sheets to enable greater heat distribution, meaning they’re not very good insulators. In contrast, the medium and thicker layers were found to have their microparticles to not be in contact as much, enabling greater levels of insulation. Additionally, the researchers found resiliency of the stacks exceeded the researchers’ expectations.

“You could use these stacks to insulate a lunar habitation, but astronauts will inevitably have little accidents where they bump into them,” said Dr. Igor Bargatin, who is Associate Professor in Mechanical Engineering and Applied Mechanics at UPenn and a co-author on the study. “When we’re talking about long-term habitation on the moon, it’s really important to have tough materials that can last long enough.”

This study comes as NASA has ambitious plans to not only send humans back to the Moon for the first time since 1972, but with the long-term goal of establishing a permanent human presence on the lunar surface. While NASA is targeting the lunar south pole region due to the large deposits of water ice within the depths of certain craters, developing the technologies to ensure humans can both work and live on the lunar surface for long periods is essential for establishing a long-term presence.

As noted, the lunar surface experiences extreme temperature swings, ranging from 70 to 127 degrees Celsius (158 to 260 degrees Fahrenheit) in the Sun and between minus 238 to minus 247 degrees Celsius (minus 396 to minus 413 degrees Fahrenheit in the shade. While one day on the Moon is 29.5 Earth days, half of this is continuous daytime, and the other half is continuous nighttime. Therefore, developing technologies that can withstand these temperature swings and long-term exposure is paramount for humans to establish a long-term presence on the Moon.

How could layered mylar help insulate Moon habitats in the coming years and decades? Only time will tell, and this is why we science!

As always, keep doing science & keep looking up!