You’ve probably seen the astronauts floating around in their spacecraft around the Earth. But have you ever wondered why? The answer is that they are in free fall because they are only affected by the gravity of the earth and no other forces. On the other hand, if you stand on the ground it will counteract gravity so that you are in balance and feel a weight.
When you use the word weightless, in most cases, you mean that you are in free fall, and not the absence of gravity. The astronauts in orbit around the earth are constantly in free fall at a rate that is adapted so that they do not fall down to the earth, but constantly fall “around” the earth.
Gravity (of Latin gravis meaning heavy), or gravity, is one of the four fundamental forces of the universe. It is the attractive force that masses expose to each other, and gives rise to what we call mass weight.
On the moon, with less gravity than the earth, your weight also becomes smaller. Your mass, on the other hand, is the same as on earth.
If, on the other hand, there is no force to counteract gravity, you cannot feel any weight. Then there is nothing to stop you from falling. You are then in so-called free fall – you are weightless.
It’s just a free case that makes the astronauts weightless. Both the astronaut and the space shuttle – and the meatballs, pencils and everything else in the space shuttle – are freely around the earth, and everything falls just as fast. Thus, note that weightlessness is not the same as the absence of gravity.
Let’s study the concept of free fall a little closer. On earth, if we neglect the air resistance, all objects fall just as quickly towards the ground. The earth’s gravity causes all falling objects to accelerate with the constant acceleration of 9.81 m / s2. This means that all objects fall so that the speed increases by 9.81 m / s for every second they fall. (In practice, of course, we cannot neglect air resistance, and we all know that a rock falls faster to the ground than a spring.)
The astronauts in orbit around the Earth are constantly in free fall at a speed that is adjusted so that they do not fall to the Earth, but constantly fall “around” the Earth.
Doing experiments in microgravity (defined as an environment very close to weightlessness) has many advantages from a research point of view. And microgravity can be achieved in two ways.
One way is to travel away from Earth because gravity always decreases with distance. To reach a point where the Earth’s gravity has been reduced to, for example, one-millionth of gravity on Earth’s surface, we must travel 6.37 million km away from Earth (almost 17 times as far away as the moon). But it seems very impractical, at least for manned spacecraft. Fortunately, there is an easier way to create microgravity – free fall!
SPACE STATIONS ISS
About 400 km above our heads, the International Space Station (ISS) is spinning. This station is the largest international collaboration ever. Together, the European Space Agency (via ESA’s 15 member countries) works with the space organizations in the US, Russia, Japan and Canada to develop, construct and build a space station. The last space shuttle to ISS was sent up in 2010.
The gravity at 400 km altitude is about 90 percent of what we know on the Earth’s surface. But the space station’s movement around the earth means that everything in the station is in a free fall and becomes weightless.
Think about how life is on board. What happens to the body in weightlessness? How to go to the toilet? What does one eat? One can compare the final extent of the ISS with the height of a 20-story building and the surface of two football pitches. The station is scheduled to take four years to build (effective time) and it can take a crew of 2-7 people.
The height of the station to move means that the station must have a short turnaround time in order not to be pulled into the ground. The station’s speed is about 8 km/sec, which means that one lap takes 90 min. Or put it differently: The sun rises or goes down every 45 minutes. A difference at that height is that the stars glow brighter and with brighter colors than on the earth’s surface.
Like everything at the space station, the food must be packaged and stored in a way that it does not float away. For the food to last a long time, it is freeze-dried. You add water to the package and then heat the food with warm air. When the space shuttle arrives at the station, astronauts can also get some fresh food. When the food is cooked it is placed on a specially designed tray that holds the packaging. The astronauts then use a fork or spoon. If the food is sufficiently sticky, it sticks to the cutlery, otherwise you may shovel the food into your mouth.
If the contents of a package are liquid, straws are used. But on Earth, the liquid is sucked up and then gravity pulls it down
again. In space, the liquid flows until you stop it. Therefore, the suction tubes have clamps to stop the liquid. “Dropped” liquid forms spherical drops that travel around in the air.
When the meal is over, leftovers and waste are packed and stored until the next visiting spacecraft arrives and can take care of the garbage. It is either the space shuttle or more commonly Progress, an unmanned vehicle that can transport food, air, water and other supplies to the station.
It has been found that the smell and taste change in space. The Astonauts want the food
more spicy than usual on earth.
Each astronaut included in the crew onboard the ISS has a small space of its own. It’s no more than a closet in size. IN
In their own space, astronauts can have pictures of their loved ones, set up their mascots and store their personal items. Here is a window and the sleeping bag is secured with the help of rubber bands.
As the sun goes up or down every 45 minutes, the astronauts need to use some form of blindfold. Likewise, it allows a lot of onboard ISS from fans and electronic equipment. Therefore, their own bedrooms are padded on the inside. But earplugs can still be good to carry.
In space, you can sleep on the best air mattress. Although you do not need the mattress, you can sleep on air! Think, no sheets to wash! But in order to avoid going around the station, an astronaut who needs to sleep will be strapped on. Most astronauts use a sleeping bag to sleep in, but some prefer to just be strapped. Sleeping bag or not, everyone sleeps in the same position: The body is straight and the hands naturally flow in front of the body with limp wrists.
The bathroom is also no bigger than a closet. Inside, there is a toilet seat that you have to strap on and a sink that you have to put your hands in. The toilet works almost like a vacuum cleaner. When you open the lid until the toilet begins to fan in the seat to let. The fans draw air through holes under the seat. Without the suction, nothing would gather in the toilet, but float around like everything does in weightlessness. It is important that there is enough suction from the toilet so that the poop does not stick to the body!
When to sit down on the toilet opens you first cover the lid, fasten your feet and then tighten the thighs so you can remain on the toilet seat. Kisses are made in a special container and every astronaut, woman like man, has his own nozzle. Urine is collected separately to be able to separate air from the liquid. It is done in a centrifuge and then the urine can be taken. The urine contains a lot of water and when it is purified the water could be used in the station’s cycle.
Today, this is not done for ethical reasons, according to the Space Agency.
In the toilet seat is a bag that collects the waste. When you’re done, tie the bag together and send it down into the toilet seat. The bag from the toilet ends up in a large container and almost everything goes away with other waste. Some stools are stored and taken to the soil for analysis. A new plastic bag is then put on the chair and the lid is folded down. The fan will not turn off until the lid is closed. No one leaves the toilet lid up in space!
When you have been to the toilet, wash your hands. The water must not enter the space station because there is a lot of electronics that can be short-circuited. Therefore, a sink that is more or less closed and only hands can be inserted. The water also does not flow like on earth, but forms balls that float around.
Therefore, you spray water on a towel and then wipe your hands with it.
You take a shower the same way. You wipe off with a damp towel. You can also splash water on the body and then dry it. The water from the shower is then vacuumed up before the door to the shower is opened. A shower in space takes much longer than one on earth!