Why are we weightless in outer space?

A strange piece of news has caught the eye of a lot of people in October 2021. A Russian spacecraft attached to the International Space Station (ISS) on October 5, 2021. That is where they plan to begin filming the first full-length movie in space. A Russian actress, the film director and a veteran astronaut were in it. The film’s cast and crew are getting ready to face a lot of challenges, one of them being weightless in space.  

What is weightlessness in space or zero gravity? 
The sensation of weightlessness, or zero gravity, happens when the effect or pull of gravity is not felt. Actually, gravity exists everywhere. There is no zero gravity zone in the universe. What is the force of gravity? It is a pulling effect between objects that have mass. The Earth has mass and the astronaut has mass, so they are attracted by each other’s pulling forces.   

But astronauts in space usually do not feel this effect. It’s because the pull of gravity is less than Earth. Astronauts float around because the rate at which they are falling is equal to the forward, i.e. opposite push of gravity. With two bodies, a planet and a person, exerting the same amount of force, the astronauts neither go up or down, they simply float.  

For that matter, the International Space Station (ISS), is also in a perpetual free fall above the Earth. With its forward motion equalling the speed of this fall toward the planet, it’s in arrested motion, hovering in space. And the ambitious film is going to be shot on this floating space station!  

But why is floating around a problem? 
Not having to bear body weight on our feet sounds relaxing, right? Wrong. There are many long term health problems associated with it. Bones and muscles weaken, body fluids get imbalanced, muscles stiffen and the heart starts malfunctioning. Think of it as the sensation we get while speeding in a roller coaster or giant wheel. This sinking feeling makes some people throw up or feel queasy. An astronaut’s job requires living with that feeling, which makes floating around not so funny anymore.