The big problem of the space trips and the long stays in the space is the microgravity. We are still far away from the scenographic spaceships of the best science fiction movies, where their passengers easily walk on the long hallways. Or from the rotary space station, small or big, like in the shining example of Elysium, where the centrifugal force is able to recreate the artificial gravity. Even if right this last example might be the best solution.
Today the biggest problem is right what means a stay of months in lack of gravity, or almost. The effects on the body of the astronauts are visible and at the moment it is unthinkable to extend the permanence in the space before to find a solution to recreate the gravity.
The microgravity and the effects on the astronauts
At the moment the astronauts that spend many time in the space, about six months on board of the ISS, for example, live this experience in the almost total lack of gravity. Almost because the gravity zero doesn’t exist. One talks, infact, of microgravity, and not of lack of gravity, because it is there but in a really reduced quantity so to allow us to fly around the station.
During the permanence of the astronauts in the station they follow a strict scheme of excercise, to limit the problems due to the microgravity. Even though this, once came back to Earth, they aren’t able to stand on their feet and they have to spend few days with some experts that follow them before to come back to the normality.
How to recreate the gravity
By watching science fiction movies it seems really easy, a rotary station or a huge electromagnetic force should be able to keep us with the feet on the floor even in the space. However it isn’t so easy.
In the space the up and down doesn’t exist, it doesn’t exist nothing that tells us where to walk and nothing that allows us to do it. It isn’t so possible to walk between the hallways of a spaceship like in a movie, or maybe yes?
It isn’t possible to manipulate the gravity, but we have the knowledges and the skills to recreate it artificially. The centrifugal force is the closest one to the gravity force. A spaceship able to rotate on its own axis will create a centrifugal force that will allow its passengers to walk on the internal walls of the most external part of the spaceship. In this way we will have the feeling to live like on the Earth, with an almost normal gravity.
This kind of spaceship have been shown in many science fiction movies, from 2001 Space Odyssey, to The Martian The survivor, until Interstellar. But so why we weren’t able to realize them yet?
The problems of the artificial gravity
Teoretically a rotary spaceship is possible, but in the moment to really realize this kind of structure starts to arise many problems. First of all is the vehicle strength. The constant rotation, infact, will affect the spaceship with strong sollecitations that the materials currently used aren’t able to handle.
We will need to realize structure extremely stronger with an incredible increase of the costs.
The second problem is the size. To arrive to simulate the same gravity that we feel on the Earth we will need to build spaceships or space stations really big. A station of the diameter of 300 meters should rotate on itself 60 times per minutes to arrive to simulate as much gravity as the Moon one, which is only a sixth of the terrestrial one.
If we consider our current space station, instead, the ISS, it can’t fully rotate on itself, but we should consider the single modules. They have a diameter of just 4,5 meters and to simulate the terrestrial gravity they might rotate 20 times per minute. Doing that, by the way, we will really have the feeling to be inside a centrifugal and this will generate a further feeling of dizziness. By arriving to create circulatory problems and a lack of blood supply to the brain.
How much it is missed to recreate the artificial gravity?
It is even true, though, that the problems aren’t insuperable and that soon or later we will be able to realize a space station with artificial gravity, but when?
For a correct gravity and without the risk that the astronauts will suffer of any medical complication, the station should have a ray of 3,6 km and make a rotation every two minutes. At the moment this kind of structure is unaffordable for the quantity of material and the costs. But it isn’t impossible and, instead, on paper it is already possible.
This post is also available in: Italiano