Two studies about the psychological and health effects of living in space — CHAPEA and Biosphere 2
Four crew members completed the first mission of the Crew Health and Performance Exploration Analog (CHAPEA) on July 7, 2024. It was a 378-day affair, where the crew experienced how it would be to live on Mars, and NASA gathered data on the effects an extended stay would have on the health and cognitive performance of a small crew.
The habitat built for this mission, Mars Dune Alpha, considered the raw materials found on Mars and had reasonable dimensions for a crew of four. The facility is 1,700-square-foot with private crew quarters, two bathrooms, a kitchen, and dedicated areas for medical examination, recreation, fitness, and work.
We might ask, Why is NASA doing this? It is one of the many programs NASA is conducting to prepare humans for future explorations to the Moon and Mars. These missions are a way to gather information on how crews will perform when faced with significant workloads to support their habitat, conduct science, and deal with problems and even possible equipment failures. Also, to assess how restricted use and availability of water, limited food, small quarters, no blue skies, or the freedom to escape to enjoy the outdoors will affect the crews.
But this is not the first project that puts humans in these harsh conditions. CHAPEA reminded me about Biosphere 2, a project that included the two objectives of the NASA mission and also wanted to demonstrate the viability of the ecological systems on Biosphere 1 (as they called Earth) to support and maintain human life in another planet and how it was affected by the interaction between humans, farming, and technology. For this, they built a 137,000 square-foot facility with five different ecosystems or biomes: oceans, mangrove wetlands, tropical rain-forest, savanna grassland, and fog desert. It also had grounds to grow crops, some animals (goats, pigs, and chickens), fish, insects, and even invertebrates.
Biosphere 2 had only two missions. The first one had a crew with one medical doctor and seven researchers who lived in this place for two years –from 1991 to 1993. The second mission was in 1994 with a crew of seven and lasted about six months.
For now, CHAPEA plans to carry out three missions, each with four people, and lasting about one year. The first crew started in 2023, with the second starting in 2025 and the third in 2026.
The technology behind these projects.
Focusing on the technology developed or used in these projects, we realize these were quite different. In the case of CHAPEA, the mission focuses exclusively on human factors and only requires building isolated quarters for the crew. In this case, the habitat for CHAPEA was small enough to be built in a hangar at the Johnson Space Center in Houston, Texas. For this, NASA used a 3D-printing reddish building material, simulating the regolith on Mars that NASA expects might be used to build habitats for long-duration exploration. Considering 3D-printed buildings are now a reality, this building method is a great option to eliminate the need to send large amounts of building material to Mars.
Credit: R. Diaz
Biosphere 2, on the other hand, was built 35 years ago and with private funds, which makes its achievement even more amazing. Because of its dimensions and objectives, Biosphere 2 was built in Oracle, Arizona. It was made of steel frames, steel tubing, and high-performance glass to create a perfectly airtight structure. Thinking about the Earth, the team designed it to produce oxygen and remove CO2 through all the plants in the different biomes of the facility. The flow of air and temperature of the ecosystems and habitat were regulated using closed-loop pipes, air handlers, and a huge energy center in the basement. Because there was no air exchange with the outside world, the engineers had to think about a way to counter the strong forces that a constant volume of air would produce when the air heated and expanded during the day and then when it contracted at night. To solve this, they built a variable volume structure that acted as a diaphragm, called “the lung,” which inflated and deflated as needed to maintain the air pressure stable inside the facility through day and night.
The human psyche and health
The only common theme between CHAPEA and Biosphere 2 is the study of the human psyche and health due to the stressors of living in outer space. First, I will focus on the topic of health as it relates to the food in these missions.
In the CHAPEA mission, the crew ate packaged food, just like the food astronauts eat at the International Space Station, and supplemented with the produce they grew in indoor home gardening systems. In Biosphere 2, getting food was more complicated. First, they had to grow their food and then deal with the realization that their fields were not getting enough light to produce the amount of food they needed. Some papers about the mission talk about reports of hunger from the Biospherians, as sometimes the crew was called. However, medical markers indicated that, even when thin, their health during the two years was excellent.
Now, focusing on the psychological state of the crew, the only information we have now is from the Biosphere 2 mission, which indicated that the psychological aspect was a little more complex. It was said that the reduced oxygen and the restricted diet — low in calories and nutrient-dense — contributed to low morale and eventually divided the crew into two factions. That might be one of the reasons, but compared to the world we live in now, these behaviors seem normal in humans, and probably not all can be due to the hardship they experienced inside the facility.
If we compile a list of things that worked and did not work for the Biosphere 2 missions, we might realize that we learned a lot. Unfortunately, this is not the message going around at the time of these missions. Many publications about the project criticize or talk about the criticism the mission received from the public. One of the most known was when the public learned about the injection of oxygen into the facility and the introduction of a CO2 scrubber, both done to make up for the steady decline of oxygen that had become unsustainable halfway through the mission. This problem was later associated with the carbonation of concrete, which was sequestering the carbon and oxygen in the facility and contributing to the problem. This criticism, of course, was a clear lack of understanding and tolerance from the public about how experimentation and science work and how sometimes changes to the plans are permitted if that means it will lead to more discoveries in the future. Unfortunately, this and other allegations contributed to the closing of the facility, and, with that, we might have missed an opportunity to be better prepared to live in outer space and to learn more about how our Earth works.
Fortunately, Biosphere 2 did not disappear and still operates as a research facility run by the University of Arizona. It now works as an open but controlled environment and is used to do research about the biomes on Earth, human effects on oceans, and even how to build a hydroponic system for space that can be used to feed the colonies on the Moon and Mars.
Considering the fate of the two Biosphere 2 projects, I hope we can find out everything that NASA learned from the CHAPEA project, in particular, what worked, what went wrong, and what to do to solve it. Taking failures as opportunities for improvement is how successful companies like SpaceX or organizations like NASA have achieved great things. We should be constantly reminded of the words of Thomas Edison when questioned about all the failed experiments that led to the invention of the light bulb — I have not failed 10,000 times; I have successfully found 10,000 ways that will not work.”
Credit: NASA