It reserved a surprise for the heart of astronaut Scott Kelly who had spent 340 days on the International Space Station. Investigations carried out after returning to Earth on March 1, 2016 revealed that the left ventricle of his heart muscle lost 27 percent of its muscle mass and shrunk in a stable manner. The research was done by Benjamin D. Levine of the University of Texas. In the absence of weight the whole body is upset and the muscles, in particular, no longer make the effort to counteract gravity, lose tonicity. The heart itself, having less difficulty in pumping blood, is known to undergo a reduction in mass which in some cases can even reach thirty percent. But after returning to Earth, everything generally returns to normal.
The stay in orbit
Investigations on Scott Kelly have continued in greater depth to the point of instead highlighting the constant loss. But I don’t have any strange symptoms from being in space – Kelly reassured -. Today, if they let me, I’d do it all over again. Now Kelly retired from NASA but his conditions have always been compared with those of his brother who remained on the ground, also an astronaut, just to grasp any differences.
During their stay in orbit, various systems of the organism suffer consequences: bones lose calcium, blood circulation swells the astronauts’ faces because blood reaches the head more easily and extreme parts such as the hands and feet are less oxygenated. Furthermore, the cells of the eye are also altered and the immune system is weakened.
I cosmonauti russi
To combat the change that affects especially the long six-month missions that are now the standard, astronauts have to perform physical exercises for about an hour and a half every day. And so did Scott Kelly and his companion, Russian cosmonaut Mikhail Kornienko, who stayed on board for the same time. But on the Russian side it was not communicated whether the consequences were the same. Among other things, in recent days a research by Russian doctors on the causes of death of their cosmonauts showed that almost all of them were due to heart attacks.
The parallel with the swimmer
The dr. Levine highlighted a correlation found with swimmer Benoit Lecomte who in 2018 tried, unsuccessfully, to swim across the Pacific Ocean. But remaining in the water for eight hours straight for 159 days (then he slept on a ship that followed him) he found himself in a horizontal condition that produced effects on his body similar to those found on the astronaut, that is, a reduction in his mass.
Preparations for Mars
NASA explores very carefully the effects on the human organism in view of the human mission to Mars that is preparing for the thirties of the century. The astronauts will have to make a crossing of about seven months, then stop on the Red Planet where the gravity is one third of that of the Earth and finally resume the journey home. All this for about three years in conditions of zero or reduced gravity. It is therefore essential to know the consequences in order to prepare corrective interventions.
March 31, 2021 (change March 31, 2021 | 17:14)