Human analogue studies help space agencies prepare for deep-space missions
In certain areas of research, it is sometimes necessary to recreate an environment that acts as a substitute for an inaccessible or dangerous one, like space. In these cases, researchers will conduct analogue studies. During a space analogue study, researchers can test technologies, equipment, vehicles, communications and anything else involved in a space mission.
These studies allow researchers to learn as much as possible about effects of space travel on humans. They can even try out new ways to decrease risks, while avoiding potential complications and danger.
Kinds of analogue studies
As Canada and other countries prepare for deep-space exploration, human analogue research helps us understand the adverse effects that long missions could have on astronauts' health. Here are three types of human analogues that space agencies conduct:
- Confinement analogues, which test how well people react to being in small spaces for a long time
- Bed rest experiments, where volunteers are bedridden, often with their heads angled six degrees lower than the rest of their bodies, for weeks to mimic the weightless environment that astronauts experience in space
- Dry immersion experiments, where volunteers float in a tank of water covered by a waterproof barrier – again, as a substitute for weightless environments
Agencies such as NASA and the European Space Agency conduct regular analogue studies. The Canadian Space Agency (CSA) supports several Canadian bed rest and dry immersion analogues.
How analogue studies work
Analogue studies are diverse: they have different protocols and objectives. The CSA is funding bed rest and dry immersion analogues: let's examine how these work.
A participant in a Canadian bed rest study is doing high-intensity interval exercise to find out if such a preventive measure can help reduce the negative effects of inactivity. (Credit: Research Institute of the McGill University Health Centre)
Bed rest: In these analogues, volunteers spend up to 70 days with their heads angled 6 degrees lower than the rest of their bodies. They eat, sleep, exercise, shower and conduct all other activities in this position as researchers monitor their health. Without gravity pulling blood to lower areas of their bodies, volunteers adapt to bed rest much as they would if they were in space. They also lose strength, as astronauts do when they're weightless.
Bed rest studies also allow researchers to try out solutions to the problem of weightlessness. For example, artificial gravity and exercise are two things that researchers believe can keep astronauts healthier. Some studies use gravity simulations as well as exercise to see how much they help.
Participants in a dry immersion experiment float in a liquid environment. (Credit: CNES/MEDES–Emmanuel Grimault)
Dry immersion: Dry immersion experiments are especially useful because they are "supportless," thus better mimicking the weightlessness experienced in space.
In these analogues, volunteers float for five days in a tank of water covered by a waterproof barrier to keep them dry. Because volunteers are almost completely immersed, researchers can study how their bodies adapt to microgravity – especially their bones and cardiovascular systems, which become weaker in a weightless environment.
What analogue studies reveal for people on Earth
Analogue studies have usefulness far beyond their applications in space. Bedridden people and the elderly suffer many of the same health challenges as astronauts on long-term missions. Researchers have high hopes that the findings of their analogue studies will be used to help people here on Earth.