Behind the story: #2 Weightlessness and Darkness

Let’s take a more in-depth look at what I described in the second part of “Somewhere out there”. Just a quit reminded, I wrote about a cylinder with you in darkness and weightlessness. As well as about a window and how to get there. So, let’s get started with the cylinder.

A cylinder made of steel

Why are we in a cylinder made of steel now? Because, as we learned last time, we need something able to hold an atmosphere to breathe. The shape of it doesn’t really matter. However, a cylinder or a sphere can handle pressure better than for example a box. For the material and the size, I got some inspiration from a rocket currently in development. Some of you might know it by the name Starship from SpaceX. Other materials, like for example aluminum alloys, would work too. The only requirement is, they must be able to hold a gas with the pressure of 1 atm against vacuum.

Speaking of the gas or more precisely the gas-mixture. It’s made up of 80% nitrogen and 20% oxygen. This is not only quite like on Earth, it’s also almost the gas mixture used on the Internation Space Station. As humans, we would only need oxygen to survive. However, that can be quite dangerous, as oxygen is very reactive. We learned this by experiments as well as by accidents like the Apollo 1 fire. So to keep it safe, we use a gas-mixture.

Lost in space

So, you are floating in your big can with no light and no window. Inside, it’s therefore completely dark. And by that, I mean completely dark. It doesn’t matter if you open or close your eyes, there’s no difference. You see nothing, only darkness. This alone might leave you disoriented, but you’re also floating. So, there is no up or down, no left or right. This might be no problem for you, but you might as well start to panic.

There’s also another problem. You might not experience it right away, but 60% to 80% of all astronauts get what’s called Space Motion Sickness in the first days of being in space. You might start to feel a fullness of your head or a hot face, as well as a reduction in sweating. From time to time, you might also vomit, brief but suddenly. However, nausea is not so common with Space Motion Sickness. It can be reduced by a combination of preflight training and medication. If you want to know more about it, take a look at the links below.

Flashes of light

What about those flashes of light? I just said, there is no light. Where do they come from? This is called the Cosmic Ray Visual Phenomena. Researchers believe the flashes seen by astronauts outside the Earth magnetosphere are caused by cosmic rays passing through the eye. The shapes and the colors of the flashes vary, but colors like white and blue are quite common. How they exactly form is unknown.

Astronauts reported seeing them on missions to the Moon on average every 2.9 minutes. For other missions, this goes up to once every 6.8 minutes. Although they were first observed on missions to the Moon, we still have to learn a lot about them. And we will probably dive more into cosmic rays and radiation in a future part of the story.

Getting to the window to space

Historically, windows on spacecraft have been made of multiple sheets of glass. More recently, engineers started to use other materials like acrylic and other plastics. On NASA’s Orion spacecraft they are, in fact, using a combination of two glass panes and one acrylic pane. The main purpose of windows on spacecrafts is to observe the outside of the spacecraft. Why do you want to do this? For navigation or observation. But windows also have to hold the pressure inside the spacecraft and protect against hits from outside.

How do we get there? That’s a bit more complicated, as we have nothing to pull or push against. The only things left to you are the atmosphere and our body. You can use physics and our body to rotate. But that doesn’t get you closer to the window. Therefore, you can use the atmosphere to “swim” towards the window. This, however, will take a while.

Astronauts aboard the ISS even tried this, when the Kibo module was installed. As it was delivered without most of the racks, there was a lot of space inside to move around. Up to the point, that you could get “lost” in the middle. Want to see, what the astronauts did with all this room? Take a look at https://www.youtube.com/watch?v=89gjHntYMY4&t=64s. Or watch the following videos from ESA. In the first one, you can see a reboost of the ISS. To perform a reboost, the ISS fires its thrusters to increase its speed and orbit. So, the station is accelerating, the astronauts are not – if they don’t hold on to some part of the station.

On the other hand, astronauts can also have fun in zero-g. The following video is showing some space olympics. It’s fun to watch and also interesting because you see how moving in zero-g works.

Credit for both Videos: ESA