How sleep can be comprised
Sleep can be a struggle on Earth, not to mention in space. Our bodies are adjusted to 24-hour light-dark cycles. However, maintaining this 24-hour rhythm in space or on a different planet may not come as naturally.
For instance, astronauts in space can experience as many as 16 sun rises and sets a day. Circadian misalignment and sleep loss can come at a high price for astronauts because it leads to alertness and performance issues.
That is why astronauts often need to re-align, shift their internal clocks and adhere to strict sleep regimens. Astronauts visiting Mars will be required to shift their internal clocks by 39 minutes every day to stay aligned with Mars. Otherwise, it could lead to misalignments and jet-lag like symptoms.
Sleep hygiene is also crucial. It includes a healthy diet, exercise and avoiding screen-time before sleep. Moreover, the sleeping environment, light and noise levels are important for a successful sleep episode in space.
Light exposure in space
Light is the strongest regulator of the body’s circadian rhythms. And light can be used to correctly set astronauts’ circadian rhythms and prevent sleep problems.
Previously, The International Space Station (ISS) had fluorescent light tubes installed for its lighting. This had contributed to astronauts being constantly alert and awake. Since 2016, ISS has been installing new LED lights with different settings that adjust brightness and colour this way contributing to healthier circadian rhythms and sleep.
Similarly, the mission to Mars in the 2030s also plans to use special light installations. It plans to use dimmers and different spectrum of light that would allow astronauts to better align to Mars. This is especially important considering that the natural light exposure pattern on Mars may not be sufficient to facilitate adaptation and daily phase shift by 39 minutes.
Sleep and light are as important for astronauts as for inhabitants of Earth. With a growing body of research, we can now implement different strategies and help our bodies to be better aligned and most importantly healthier.