Weightlessness causes physiological reactions in the body. Weightlessness is a special mechanical phenomenon in which an object has quality but shows no weight. When an aircraft makes a parabolic flight, weightlessness occurs for a few seconds to tens of seconds, and the gravity of an orbiting spacecraft can last for several days, months, or even years. Weightlessness is a prominent problem in aerospace medicine.
The Impact of Zero Gravity on the Life of Astronauts People have long lived in an environment with gravity on the ground. When they enter an environment without gravity, they will feel that their life habits are not adequate.
For this, several measures must be taken for the life of astronauts: design tight clothes for astronauts, because fat clothes will float; fix items in the cabin to prevent them from floating freely; pieces of food break or particles fall from the surface. Debris will fly into the astronaut’s eyes, nose, and even inhale the trachea, putting her life at risk.
Therefore, space food must be broken into pieces, one bite at a time; when drinking water, pipes should be used to prevent water droplets from entering the trachea; washing and splash water must be sucked up with a water absorber to prevent water droplets from accumulating in the air and causing damage; astronauts must use belts or sleeping bags to strap in and sleep; When walking in gravity conditions, astronauts must use hooks. Shoes can be hung from the floor (ceiling) in the form of a grid.
The physiological impact of zero gravity on the human body. People have lived in the gravitational field of the ground for a long time, and the earth’s gravity pulls blood to flow downward. In a gravity-free environment, blood redistributes, blood volume in the lower extremities decreases, and blood volume in the head increases.
Astronauts’ systolic blood pressure generally increases by 2000-2666 Pa (15-20 mmHg) compared to before flight, and mean arterial pressure increases, 1333 to 1600 Pa (10-12 mmHg), venous pressure also increases and diastolic blood pressure falls.
Weightlessness causes the hydrostatic pressure gradient to disappear, increases central venous pressure and atrial pressure, stimulates volume receptors in these parts, and reflexively causes increased urine output and decreased water and plasma volume. (about 10%). Sodium and potassium ions excreted in the urine are increased. In the weightless environment, the force on human bones decreases. Over time, muscles atrophy and bones become brittle.
In particular, weightlessness causes the loss of calcium and phosphorous salts in the bones, which weakens astronauts after returning to earth. Weightlessness can also cause a decrease in red blood cells (8% to 17%), an increase in white blood cells, a decrease in T-lymphocytes, and a decrease in immunity.
In a gravity-free environment, most astronauts will also experience vestibular-autonomic reactions, leading to dizziness and spatial disorientation, nausea, vomiting, pale skin, sweating, and dizziness, all of which will affect their ability to work. This symptom usually appears in the first week of the flight and then the symptoms disappear.
Preventive measures for underweight: To prevent the adverse effects of underweight in astronauts, comprehensive measures are needed: astronaut training, reasonable work and rest system, reasonable diet and nutrition, physical exercise and drug prevention.
Astronauts must maintain adequate rest and sleep; eat foods rich in potassium, sodium and calcium ions and drink salt water before returning to replenish water, increase circulating blood volume and improve positioning resistance; strengthen physical exercises during space flights.
After the astronaut’s return to earth, after a few days to a month, all the physiological reactions caused by weightlessness will disappear, and the body’s functions will gradually return to normal.