Stress in Space - and Why Hibernation Might be the Solution

Written By Edgar Salus

In June 2024, two Nasa astronauts traveled to the International Space Station (ISS) on what was planned to be an eight-day mission. However, their Boing Starliner experienced technical problems on its way to the ISS and the spacecraft returned to Earth “un-crewed” after the return journey was deemed too risky for astronauts.  Its crew, Sunita Williams and Barry Wilmore, remained on the ISS and will now only return in February 20205 with SpaceX after around eight months in orbit. 

This image made from a NASA live stream shows NASA astronauts Suni Williams and Butch Wilmore during a press conference from the International Space Station on Friday. (NASA/AP)

The two NASA astronauts gave a press conference about their experience of being stuck on the ISS for months in mid-September 2024. They were both in good spirits and said that they felt "grateful" to spend more time in space, despite difficulties. Williams and Wilmore also stressed that they had been aware of potential delays and risks of their mission because 90% of their training had been about preparing them for the unexpected. 

According to NASA, astronaut candidates must complete a rigorous two-year program that includes water survival training, advanced robotics, aircraft flight readiness, extravehicular activity and Russian language courses. 

Physical Challenges

Living in space is undoubtedly an unparalleled experience, but it can take its toll on an astronaut’s body. Apparently, half of the astronauts return with weaker immune systems from the ISS. 

European Space Agency (ESA) astronaut Paolo Nespoli rests in his sleeping bag in the Harmony node of the International Space Station.
NASA

Some of the common physical challenges of living in space include loss of bone density, muscle atrophy, and cardiovascular problems. The lack of gravity in space makes it difficult for the body to maintain muscle and bone mass, which can lead to significant health problems. In addition to this, radiation exposure can also impact a person's physical health, as they are exposed to higher levels of radiation than they would be on Earth.

Psychological Challenges

Just as spaceflight can challenge the limits of the human body, it can also be psychologically taxing. For example, life on the ISS is quite different from life on Earth. Crew members experience multiple sunrises and sunsets each day, spend their time in a confined space, have packed schedules, and deal with microgravity. 

These and other conditions during spaceflight can negatively affect the performance and well-being of crew members. According to NASA’s Human Research Program in Behavioral Health and Performance, severe sleep deprivation, coexisting in confined environments, and performance pressure all put astronauts at high risk for emotional distress and anxiety. 

Countermeasures Against Physical and Mental Health Effects

To combat the effects associated with prolonged exposure to microgravity environments, astronauts use countermeasures such as exercise routines that are specifically designed for maintaining healthy bone mass density while also building up cardiovascular endurance. They also use exercise equipment optimized for use aboard spacecrafts/habitats like treadmills or stationary bicycles utilizing resistance bands which provide more natural resistance than free weights in microgravity conditions. Astronauts also receive extensive training to help them apply self-assessment tools and treatments for maintaining their behavioral health. In-mission support, such as care packages, teleconferences with a psychologist, and journaling, help astronauts maintain motivation and increase morale. 

Apparently, also the sight of our planet Earth, vibrant with life and wonder, has a profound positive emotional impact on those who are lucky enough to see it. Seeing the Earth from space can fundamentally change an astronaut’s outlook on life, society, and the human experience. The two NASA astronauts currently stuck on the ISS since June 2024, also stressed how much they enjoyed watching our planet from space.

Additional Problems in Future Space Missions 

Missions to space are going to increase in distance and duration, with NASA researchers determined to launch human missions to Mars by the early 2030s. As space exploration continues to advance into unchartered territory, astronauts may quickly find themselves without the view of our planet Earth, which kept their predecessors emotionally tethered to humanity here on Earth. 

Further, during a mission to Mars, astronauts would be subjected to a two-way 20-minute delay in communications, meaning they could wait up to 40 minutes for a reply from mission control making real-time, in-mission psychological support from Earth impossible. Instead, it would be necessary to have tools that will allow astronauts to monitor and maintain their behavioral health more autonomously with no real-time support from ground control. 

Hibernating in Space

One possible solution to long, risky, and challenging space missions that is often mentioned is hibernation. In fact, several space agencies, including NASA and ESA, are investigating the possibility of hibernation for long space travels. But how can humans do it?

Hibernation Infographics ESA/NASA

Hibernation is a state in which living organisms slow down their metabolic processes while maintaining essential functions. In this way, mammals like bears and bats can survive winters, cope with water scarcity, and preserve their energy. Given these perks, NASA, ESA and other space agencies are studying whether human bodies can hibernate to survive long space travels. The main focus of these studies is on the psychological advantages as hibernation can reduce the psychological stress and boredom of the crew on their trip to Mars. 

On top of the mental gains, this metabolic state can yield many logistical advantages. In particular, the space agencies are looking into a mechanism called torpor. Torpor can be inherently or intrinsically introduced. It reduces the animal's metabolic state and results in the need for less water and less food. According to ESA research, astronauts going to Mars would require  about 30 kg of food, water, air, and other suppliers per day. Thus, hibernation can significantly cut down on their essential needs. 

Additionally, hibernation might have positive impacts on astronauts' health conditions. Research in animals suggests that bodies of hibernating astronauts might waste away much less than the bodies of those awake in microgravity. Upon arrival, these hibernators would thus be fit and ready to commence challenging exploration almost straight away after regaining consciousness.

According to ESA’s studies, hibernation would happen in water containers acting as protecting shields for in-orbit astronauts. Once inside these pods, they would get drugs to adjust metabolism, reduce core temperature, and initiate torpor. Upon the arrival back on Earth, the astronauts would wake up and gradually readopt their normal functional metabolism.

In science-fiction movies, astronauts frequently cross vast distances while hibernating. (Image credit: 20th Century Fox, Aliens)

For all these reasons, hibernation or torpor has long been a staple of sci-fi space movies. From "Alien” to "2001: A Space Odyssey,” fictional space travelers have crossed vast distances cocooned unconscious inside high-tech pods while AI machines and android robots keep their spacecraft on a steady course. 

Despite being a sci-fi trope, putting humans into long-term induced torpor may not be a far-fetched idea after all. According to scientists at ESA, depending on funding availability, the first human torpor trials could take place as early as the mid-2030s. 

In a few decades, we might actually witness the first hibernated astronauts returning home from Mars.


Edgar Salus
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