Being in a state of weightlessness, how do astronauts stay healthy

The National Aeronautics and Space Administration (NASA) will allow them to leave the Earth only when the astronauts are in their best physical condition. However, the scope of activities on the International Space Station (ISS) is only as large as a football field. Living there for a long time, the body is extremely vulnerable. Then, Peggy. Whitson, the longest-serving astronaut in space in the history of the United States, in his nine-and-a-half-month microgravity space life, how to ensure that the body and brain do not shrink? The secret is that there is a gym dedicated to astronauts on the ISS!

As a life on earth, the human body is not easy to adapt to the microgravity environment. In the first few hours of the mission, half of the astronauts will develop space adaptation syndrome (SAS, commonly known as “space disease”) until their vestibular system is re-adjusted to adapt to weightlessness.

Fluid displacement is another common problem. Because there is no gravity, body fluids are more widely distributed throughout the body—in other words, it exudes from blood vessels and cells, causing the body to lose up to 22% of plasma, while plasma can transport red blood cells to the body. system. In space, as the amount of blood pumped is reduced and the heart begins to shrink, when the astronauts return to Earth, they will have symptoms of “bad standing endurance.”

For example, when you are lying up quickly, if you feel dizzy, you will have poor standing endurance. At this time, your heart rate will increase and your blood pressure will rise to help more blood return to your heart before you faint.

But for astronauts, when returning to Earth, due to gravity, the exuded body fluids will all concentrate on the lower limbs, resulting in poor standing endurance. Therefore, they may stand for more than 10 minutes, otherwise they will faint, and this symptom will last for a while.

This fluid displacement can cause other problems, such as greatly increasing intracranial pressure, flattening the eyeball, and possibly damaging the optic nerve. NASA surveyed 300 retired astronauts, 23% of which were short-term missions (less than 6 months) and 49% of long-term mission performers mentioned that their far and near vision were both in flight. The impact, this effect will last for years for some people.

It’s not just the heart, but after losing the gravitational pull of the earth, even the muscles and bones will decline. “The most serious of these is osteoporosis in the skeletal system, as well as muscle loss and loss of strength in the muscle system,” said Dr. Richard Schuling, a NASA aviation doctor. “Cardiovascular disorders will stabilize in about three weeks and will not continue to worsen, but these two conditions will continue to worsen.”

Schuling said changes in bone marrow affect red blood cells. The resulting, resulting in “space flight anemia”, but this will not have much impact on healthy people. In addition, the International Space Station orbits the Earth approximately every 90 minutes, half of which is half day and night, which creates another problem for astronauts: insomnia. NASA is currently working with Harvard to study how to avoid insomnia.

Although NASA now requires astronauts to have 2.5 hours of exercise per day, half a year of space life will result in an average loss of 11% to 17%, about 10% stamina and 2%. To 7% of bone density.

Schuling explained that astronomers lose 1% to 3% of their bone mineral density each month before NASA takes action, “and women who are 55 years old post-menopausal lose a bone density of 1 per year.” % to 2%.” What’s more, the waste of calcium accumulates in the kidneys, which greatly increases the probability of astronauts suffering from kidney stones.

The emergence of the gym on the International Space Station is precisely to address the above issues. There are 3 types of equipment for astronauts: the treadmill dynamometer, the stationary bicycle; the fixed treadmill with the restraint system, which simulates the gravity effect when the astronauts run; and the advanced resistance training device (ARED), A “weightlifting” system that relies on a flywheel and a vacuum tube to create drag.

Thanks to these devices, “the astronauts are much better when they return to the ground, and the recovery speed is much faster,” Shuling said. “If the astronauts can persist in and take physical training in the space station, after completing the 6-month space mission back to the ground, they will recover their basic strength, flexibility and endurance in 30 days.”

As a multi-functional strength trainer, ARED has been in use on the ISS since 2009. ARED can generate up to 600 pounds of resistance, allowing all of the astronauts’ body muscles to be exercised. NASA also recently added a training request for the abdomen and waist to alleviate the pain that appears behind the astronauts’ back.

NASA is still exploring further ways to better use ARED to improve the physical condition of astronauts, including the ongoing comprehensive resistance and aerobic training study (SPRINT), which uses ARED for high intensity and low The amount of training. At present, astronauts on the ISS perform 6 ARED trainings per week, but generally they are low-intensity exercises with repeated actions. The SPRINT team found that if you reduce it to 3 days a week, increase the intensity while reducing the number of movements, you can better avoid the loss of skeletal muscle quality and function.

The study also found that intermittent aerobic exercise is more conducive to maintaining cardiovascular function than continuous exercise. Therefore, the researchers chose to perform intermittent aerobic exercise on other days, in addition to increasing continuous aerobic exercise during high-intensity weight training.

As humans explore the solar system step by step, astronauts will once again visit the moon and eventually land on Mars. The journey to Mars will take at least half a year, and you certainly don’t want to embark on a new planet with a chunky, shrinking shape. Therefore, this kind of research is extremely valuable.

Source: Internet