Context: Space travel poses significant challenges to human health due to microgravity, radiation exposure, and psychological stress.
Relevance of the Topic: Prelims & Mains: Impacts of space travel on the health of an astronaut.
Space omics
- Space omics is a set of studies to understand how the space environment can impact the human body.
- Factors in Space impacting Astronauts:
- Radiation exposure (Unlike earth’s magnetic field that shields from space radiation, astronauts are exposed to high-energy radiation permeating the cosmos).
- Microgravity (Without gravity bodily fluids shift upward and thus increase intracranial pressure)
- Confined environments (Isolation and limited social interaction and exposure to natural stimuli)
- Time (Symptoms become more pronounced with increased stay duration in space).
Impacts of Space Travel on the Health of an Astronaut:
1. Bone and Muscle Degeneration:
- Bone Weakening:
- Microgravity results in the weakening of bones (particularly those that bear the body's weight on Earth).
- The bone density loss occurs at a rate of about 1-2% per month, increasing the risk of fractures and osteoporosis.
- Muscle Atrophy:
- Muscles in space experience reduced demand which leads to loss of muscle mass and strength.
- E.g., weightlessness in space reduces the heart's workload, leading to shrinkage of heart muscles. The cardiovascular system struggles to regulate blood pressure upon return to Earth.
- Balance and Coordination Issues: Prolonged exposure to microgravity conditions also affects the inner ear’s ability to sense movement and orientation, leading to balance and coordination issues.
- RBC Loss: Blood loses more red blood cells per day in space than on Earth. This condition is called space anaemia.
2. Spaceflight-Associated Neuro-Ocular Syndrome (SANS):
- In microgravity conditions, the fluids in the body shits upwards towards the head. This leads to an accumulation of fluid at the back of the eye resulting in facial swelling and vision loss.
- Around 70% of astronauts involved in long-duration spaceflight develop SANS.
3. Changes in Gene Expression:
- NASA's Twins Study (2016) revealed that space travel causes an increase in DNA methylation and the process of turning genes on and off (gene expression).
- Space travel caused lasting changes to 7% of the genes of astronaut Scott Kelly compared his DNA to that of his twin brother.
- High radiation exposure can lead to DNA damage, increased cancer risk, neurodegenerative effects and immune system dysregulation.
4. Psychological Stress:
Long-duration space missions can lead to psychological stress, sleep disturbances, and mood disorders.
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