What is needed to simulate gravity artificially in space?
Anyone who has watched some space movies might have seen the answer to that. A large wheel like shpace ship. The answer is theoretically correct, but the reality is very different.
The idea of spinning wheel space stations, is that their crew can remain glued to the ground instead of floating is not new. We have seen in dozens of films from 2001: A Space Odyssey to The Martian . In the 1960s, NASA fabricated a giant simulator to try to test whether the centrifugal force caused by the spin of an object could be used to simulate gravity within that object. The results were positive, but a ship like this has never been made.
The reason is purely practical. To build such a space station requires an tremendous amount of resources and money.
The first problem is the size of the station. In the present case, the centrifugal force is proportional to the diameter at the speed of rotation, and the spacecraft of this type that we see in the cinema do not worry much of calculations. For instance, in 2001: A Space Odyssey , the space station has a diameter of 300 meters and rotates at a speed of about 1 rpm. This configuration is hardly enough to simulate lunar gravity, which is 1/6 of the Earth’s gravity. To simulate gravity as the Earth’s surface would have to rotate to 2.4rpm.
If the spacecraft had a more realistic size (25 meters radius), it would have to rotate at 6rpm, which would probably be impractical to conduct experiments and disorient the astronauts. In addition, the gravity depends on the distance to the center of rotation. In such a small season, the gravity perceived in a person’s feet would be different from that perceived in the head.
Definitely, to simulate gravity in a functional way, a space station must be very large, and just putting the materials in orbit to build it is incredibly expensive. Putting one kilogram of weight into one of SpaceX’s current Falcon 9 rockets costs $ 2700. When the company starts operating its new heavy variant of Falcon 9, that price will be reduced to $ 1,650 per kilogram of cargo.
Probably the cost can be trimmed the day we are able to extract metals from the asteroids that float in the solar system and process them in space. Even then, build structures 60 kilometers in diameter as the film station Elyssium be a challenge of engineering.