Mental health in space: ISS experiments help keep astronauts happy off Earth

More than 25 years of research on board the International Space Station have given investigators new avenues into learning about astronaut mental health.

The International Space Station (ISS) has hosted a variety of experiments focused on mental health, ranging from virtual reality to taking pictures of Earth , to help astronauts during missions that can last six months to 12 months.

NASA and other space agencies want to learn how to keep astronauts happy, not only to get ready for long-duration moon missions with the Artemis program , but to reapply the "lessons learned" for isolated, confined environments here on Earth.

Here are five investigations about astronaut mental health that have been conducted aboard the ISS, which NASA highlighted in a recent release .

Related: Why a VR headset on the ISS 'really makes a difference' for astronaut exercise

Circadian Light

The Circadian Light project is testing a new lighting system on the ISS, to see how lighting patterns "help astronauts maintain a more normal daily or circadian rhythm," NASA representatives wrote in the release.

The ISS lighting panel seeks to "better mimic natural conditions on Earth" — the ones caused by the sun 's trek across our sky. The goal is to see how astronaut well-being can be improved through matters such as sleep and the reduction of stress, which also may help shift workers.

Circadian Rhythms

Circadian Light builds on an earlier experiment called Circadian Rhythms , which "examined how daily rhythms change during long-duration spaceflight and its non-24-hour cycles of light and dark," the project's investigators wrote. Body core temperature was measured using skin sensors to assess how astronauts did.

NeuroMapping

NeuroMapping aimed to dive into the brain's structure and function to see how matters such as multi-tasking change in space, and how they change again when an astronaut returns to Earth.

Overall, the results were positive, as the peer-reviewed literature showed: "Results published from this work include a study that found no effect on spatial working memory from spaceflight but that did identify significant changes in brain connectivity. Another paper reported substantial increases in brain volume that increased with mission duration and with longer intervals between missions," NASA representatives wrote. The agency also noted that gaps of at least three years between missions are most beneficial.

Crew Earth Observations

While astronauts are already tasked with taking pictures of Earth for tracking human-induced climate change , natural disasters and other events on our planet under a project called Crew Earth Observations , newer investigations also focus on how the imagery helps astronaut mental health.

"Researchers realized that taking these photographs also improves the mental well-being of crew members. Many of them spend much of their free time shooting from the station's cupola," NASA representatives wrote, referring to a wrap-around window available on the ISS for Earth observations.

VR Mental Care

— Why a VR headset on the ISS 'really makes a difference' for astronaut exercise

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— Watch trailer for 'Space: The Longest Goodbye,' new film exploring astronaut mental health (video)

VR Mental Care , an investigation from the European Space Agency (ESA), uses virtual reality technology for astronauts to simulate being in different environments. The 360-degree environment includes video and sound, and is followed up by questionnaires to assess how the astronauts felt while using the tech.

"In addition to helping astronauts, this tool could be used to deal with psychological issues such as stress, anxiety, and post-traumatic stress disorder on Earth," NASA representatives wrote.

ESA astronaut Andreas Mogensen, one of the study participants, previously told Space.com how much he enjoyed using VR for applications such as exercise, on a stationary bike. "It really makes a difference," Mogensen said. "There's something about when you see yourself biking up a hill in the virtual reality headset; you just have more motivation to pedal a little bit harder."