Remember Interstellar? Let’s talk about something fun from the movie, but we cannot leave behind the science of it. It has to be the Endurance, the modular ship in the form of a ring. It was the ship that carried astronauts on their voyage through the wormhole to a system located in another galaxy near the black hole Gargantua.
The science behind the spinning spacecraft was put forward by Caltech theoretical physicist and executive producer Kip Thorne. The perplexing fact of the ship is the ring-like structure, which was advocated particularly to produce artificial gravity. This is all thanks to the Centrifugal reaction. It rotated at 5.5 revolutions per minute to produce a centrifugal force that simulates Earth’s gravity for the astronauts. Before leaping towards the bigger picture, let’s try to understand it through a small example, take a bucket full of water and start rotating it. If you turn the bucket upside down, the water will spill out. But, if you spin the bucket over your head fast enough, you may avoid getting wet. What’s happening here is that when you spin the bucket fast enough, the contents get pushed toward the edges. In a similar way, when the Endurance rotated it pushed the contents towards the outer edge. What’s happening here is that when the endurance spins, centrifugal force acts to pull the contents to the outside and this process can be used to simulate gravity.
Now the question is how could they generate that force? At the start of its eternal voyage through the deep space, they may release some pressurized air to give a spin to the ship. Since there is no friction, the ship kept on rotating since then. Hence consuming minimal fuel and being highly efficient.
Another fascinating concept behind the Endurance is its Gyroscopic effect. It is a phenomenon wherein a body with mass, rotating about its spinning axis, tends to be stable on that axis itself, and returns to the spinning axis if disturbed. This is useful when traveling fast through space because if any space debris impacts the spaceship it’ll have a tendency to throw it off course (Newton’s First Law). Hence be stabilized back by the Gyroscopic effect. This is shown in the film where the spinning axis of the damaged endurance doesn’t alter after the docking failure of Dr. Mann’s ranger.
The Ring structure is naturally the stable structure, because of the capability to distribute the pressure force in the artificial environment the astronauts live in, despite low pressure outside. As to why it’s needed at all — the fact that Endurance is not a fast flier, it’s supposed to be in space for a long time (Romilly spent 23 years there), and being subjected to weightlessness for a long time bone decay occurs. The simplest solution is to take gravity with you, and this is a plausible way to do that by building a spinning spacecraft, though we are yet to see any such stations in real life.
Shikhar Singh, IIT Roorkee