While researchers are working on thrusters, possibilities for space colonization, and ways to provide water and power in space, other scientists are trying to understand how space affects the human body. Much of their knowledge has now been compiled in a collection of 29 articles that is the result of what is known as The Twins Study, which followed two astronauts.
What Happens to the Human Body in Space
Between March 2015 and March 2016, NASA scientists studied the metabolism of retired astronauts (and identical twins):
- Scott Kelly, who lived aboard the International Space Station (ISS),
- and Mark Kelly, who remained on Earth.
The study reveled what Happens to the Human Body in Space:
- Bones lose density at a rate of 1.5% per month
- Space travel shrink the muscles by up to 25%
- Body fluids accumulate in the upper body
- and the amount of circulating blood decreases, resulting in decreased oxygen supply to the brain
The data collected came from:
- Ten studies
- Conducted by 84 researchers from 12 universities
- NASA’s Human Research Program
After the Twin study, 56 additional astronauts were monitored to document the effects on them.
NASA Details How Space Affects the Human Body
The external factors affecting humans in space have been studied through an approach referred to as Multiomics.
Multiomics is a biological analysis in which the dataset is drawn from the:
Determining how they interact and influence each other.
In summary, the scientists have identified six key factors that determine what happens to a person’s body in space:
1. Mitochondrial dysregulation
Mitochondria (responsible for generating most of the chemical energy in a cell) work differently.
2. Oxidative stress
The space environment causes an imbalance between free radicals and antioxidants in the body, probably caused by the radiation to which astronauts are exposed.
3. DNA damage
Space radiation can also affect human genes.
4. The length of telomeres
These structures serve to protect the genetic material that the chromosome carries. Over the course of life and up to billions of cell divisions, telomeres shorten until they are so small that they can no longer protect the DNA – the cell then stops reproducing. In space, telomeres lengthen, but they return to their original size when the astronaut returns to Earth.
5. Variations in microbiomes
The genetic material of the microbes that inhabit the human body is altered by the spatial environment.
6. Epigenetic changes
The mechanisms that regulate our DNA (ie, “turn on” and “turn off” sets of genes) react to microgravity.
Scientists using this data to develop:
- Preventive measures
Understanding How Space Affects the Human Body
As space travel becomes more advanced and humanity gets closer to sending astronauts to Mars – we need to know how our bodies will cope with long-term space travel. And thanks to the largest study ever published on the subject, the picture is now emerging.