Insidious weightlessness: ISS astronauts suffer from increased growth

A stay in orbit for several months does not pass without a trace for the health of astronauts. That is why only specialists with perfect health are selected for a flight to the International Space Station (ISS). But even the astronaut’s excellent physical condition cannot guarantee that the return to Earth will take place without incident. It turns out that under space conditions in the body there are changes that lead to increased growth.

The thing is that weightlessness is a fundamentally different environment compared to our planetary conditions. Getting into a space in which the force of gravity does not work, the human body is rebuilt under new realities. In zero gravity, for example, there is an increase in the growth of astronauts. On average, after six months in orbit, namely, the expedition to the ISS, as a rule, lasts, a person’s height can increase by 4-5 centimeters.

The reason lies in the special properties of cartilage, which are manifested in zero gravity. The human skeleton consists of bone and cartilage. And if the bone tissue does not undergo any changes, being in zero gravity, then the cartilage in the absence of gravity begins to straighten. The intervertebral discs, which consist of this type of tissue, increase in size, therefore, the growth of the astronaut becomes larger.

This in turn leads to the appearance of one serious problem: the ISS astronauts may not fit in the seats by the time they have to return to Earth. For each member of the crew of the spacecraft, an individual depreciation seat of the Kazbek-UM model is designed. It provides for exact repetition of body contours to achieve maximum comfort during flight. Therefore, an increase in growth of only a couple of centimeters can cause injury on the way back to Earth.

Cushioning chair "Kazbek-UM"

But it is not all that bad. Experts have developed a number of preventive measures that can help avoid increased growth. This, for example, is a special treadmill that simulates gravity. Besides her there is a unique costume called "Penguin". This is a special Russian development, which is designed to create a vertical load on the spine. Therefore, if after some time it is discovered that one of the crew members has grown, he is recommended to take measures.

Interestingly, after returning to Earth, the effect of growth growth passes over time. The force of gravity again begins to act on the body, and the astronaut, descending from heaven to earth, becomes the same growth.

Something similar happens with man and on Earth, but only during sleep. In the supine position, there is no axial load on the spine, as a result of which by the morning a person can grow up to 1.5 centimeters. But after some time the "magic" passes, as when returning from orbit.