Outer Space Environment (Space Weather)
Let’s take a closer look at the space environment to better understand the clothing requirements, as clothing will be used in the space environment. outer space; As the name suggests, it is defined as the space that lies beyond the highest points of the Earth’s atmosphere and between all other objects in the universe.
The main environmental feature of outer space is the “almost” complete absence of vacuum or gas molecules. The gravitational pull of large objects in space, such as planets and stars, pulls gas molecules close to their surfaces, leaving the space in between almost empty. Among these bodies are some stray gas molecules, but their densities are so low that they can practically be considered non-existent.
Details defined by distances such as subspace and superspace do not matter much. In this regard, the “Armstrong Boundary” is one of the most important distances for us. Because space aside, the danger for us begins while we are on Earth.
Armstrong Limit
It is defined as the limit where human life is endangered, at 0.0618 atmospheric pressure, the temperature is around -60 degrees Celsius and starting from the 19th kilometer of the atmosphere. Let’s explain more simply. If we had boarded a fighter plane without cabin pressure and had climbed to this altitude, our oxygen mask on our faces would not have been able to protect us either.
Although outer space environment is a vacuum, outer space can be considered as an environment. In this environment, radiation and objects can freely pass through it. An unprotected human or other creature placed in the outer space environment will end its life within 10-15 seconds; Considering these bodily effects, it is quite painful and painful.
I’m sure you’ve seen questions like these. First of all, the body and the skin surrounding our body have a capacity to stretch. This vacuum (low pressure) in the unprotected environment will force the body to flex outward. For this reason, the lungs should be emptied as much as possible, not holding the breath. In addition, it should be added that the mouth, nose and eyes should be tightly closed. However, in any case, this period is directly proportional to the oxygen in the blood and how much oxygen the brain can feed, so unless there is a protected area, death is inevitable.
Image-1. Space suit upper torso (Image Credit: NASA)
What Would Happen Without Special Suits In Space?
Our goal is implemented in every aspect that exists in our world. At sea rise this pressure is 101 kilopascals, with pressure in space zero. On this journey, you will embark on a flight journey.
In its bubbles in the circle, gases can form large chambers and circles of liquid, and the skin in one large cavity. On the other hand, ureters are formed in the blood, making it convincing in shape and nutritionally.
In addition, the sudden absence of equipment suitable for the internal equipment of the liquids and gases in its content (our skin thinks about air) can also damage tissues such as ear thinners and capillaries. It is about to be completed in a nutshell and, accordingly, it will end with the final process.
On the other hand, in terms of gravity, the upward movement of the internal and spinal fluid of the body is also dependent on the load of the intracranial structure (intracranial pressure). In the process of returning to Earth, astronauts are dropped by applying the “Lumbar Puncture Method”
A second major obstacle exists at the location of a region in space. In space far from the Sun, the type-controlled side of the Earth can rise above about 120 degrees Celsius, while the shaded side can drop to -100 degrees Celsius. It comes with a problem in the existing human condition and in maintaining a close temperature zone.
Image-2. Space and radiation (Image Credit: ESA)
Are these the problems? Of course not, we’re just getting started. Other environmental factors encountered in space include:
- Microgravity,
- Radiation of electrically charged particles from the sun,
- Ultraviolet (UV) radiation,
- Meteorites and meteoroids.
They are tiny bits of rock and metal left over from the formation of the solar system and the collisions of comets and asteroids. Although usually small in mass, these particles move at very high speeds and can easily penetrate human skin and thin metal. Equally dangerous is debris from previous space missions. A tiny particle of paint moving at thousands of kilometers per hour can cause significant damage. In short, Perseid Rain, which we watch with admiration on Earth, is not something to envy for someone in a space environment.
Space Life And The Laws Of Physics
One of the biggest advantages of working in space is that objects, including astronauts, have no apparent weight. Regardless of the weight of an object on Earth, a single crew member can easily move and position that object in orbit, provided the crew has a stable platform on which to work.
The physics of working in space is the same as the physics of working on Earth. All people and things contain matter and therefore have mass. Because of this mass, they resist any change in motion. Physicists call this resistance inertia. The greater the mass, the greater the inertia.
As on Earth, objects in space need to apply a force to change their motion. How much the object moves is partly explained by Sir Isaac Newton’s “Third Law of Motion”. The law states that a force that causes an object to move in one direction encounters an equal and opposite force in the other direction.
Image-3. ISS and astronaut EVA activity. (Image Credit: NASA)
The law is more familiarly stated as “For every action there is an opposite and equal reaction”. The result of this law in space is important. A simple Earth task like turning a nut with a wrench can be quite difficult in space because it’s possible for the astronaut to spin, not the nut. As additional security measures, both the astronauts and the tools they use are fixed with threads with snap hooks. If this is not done; 14-15 if you turned the key to the left to open a nut, you would turn on your own axis.
It is easy to exert force on the earth because we put our feet firmly on the ground. We can lift heavy objects because equal and opposite force is directed from our legs and feet to the Earth itself.
The Earth’s inertia is so great that its reaction to the downward force is extremely small. In space, astronauts do not have the advantage of having a planet that will absorb equal and opposite forces during their work activities.
As described in the Third Law of Motion, pushing against an object causes the object and crew member to float in opposite directions. The speeds at which the crew member and the object move away from each other are determined by their respective masses.
For example, let’s say an astronaut is pushing a giant satellite in space. The satellite is much slower than a less massive astronaut pushing it, but the astronaut will move away from it faster and in the opposite direction.
Image-4. STS-114 Mission. ISS Robotic ARM (Image Credit: NASA)
To gain advantage over objects, the crew member in the spacesuit is supported by foot holders on a large and actively stabilized robotic arm or fixed platforms placed on the outer surface of the International Space Station.
After this information about the space environment, let’s gradually introduce the space suits, which are the main focus of the subject.
Spacesuit Designs
We mentioned earlier that a spacesuit can actually be considered a spacecraft on its own. To remind again, the purpose is; Although they have different shapes and features, they can be summarized as providing maximum protection and survival for astronauts. Aside from developing a spacecraft to be used for manned flight, just developing astronauts’ suits is a whole other world in itself.
Image-5. U-2 Plane and pilot. (Image Credit: NASA)
Air Force Use Requirement Before Space
The foundation of space suits started with the need of the American Air Force in the 1950s, and these special suits gained further momentum with the space race at the end of the decade. Parallel to the technological developments in the aviation sector, the increase in the engines and altitudes of the aircraft has revealed the need for additional equipment for the pilots.
These can be listed as oxygen support at high altitude, low pressure protection, the effect of G-force due to speed and maneuvers. Because pressure suits are required at altitudes above the Armstrong limit. Approximately 19,000 km. In an environment with a pressure of 0.0618 atmospheres from altitude and a very low temperature such as -60 degrees; body fluids and blood begin to boil and evaporate.
Image-6. Turkish female fighter pilot in an F-16 cockpit in a flight suit. (Image Credit: Turkish Air Force)
In the same way today, pilots can cope with the negative effects of G-force and atmospheric conditions by using special flight suits that automatically inflate their legs and certain compartments and prevent blood from rushing to the brain, and by using headgear that provides oxygen support at high altitudes.
The result of almost 75 years of work and knowledge are hidden behind the clothes that are used in space missions and that everyone looks up to. Despite the situations that pilots are exposed to even when they are in the Earth’s atmosphere, space air is full of much more risks and unknown dangers, which is why it is inevitable to wear more special clothes.
Despite the accumulation of all these years, space is still open to a new surprise like an unknown equation. Although these dangers can be predicted in computer simulations, it is inevitable to experience some things personally. Although lessons were learned from these experiences, unfortunately, from time to time, accidents caused the loss of astronauts.
To Use Or Not To Use Spacesuits
For this, it is necessary to start by examining the most basic issues, namely temperature and ionizing radiation. Surfaces facing the Sun in space heat up, and places in the shade get colder. This temperature difference is harmful not only to the astronauts, but also to the electronic components of the satellites.
The temperature in space can vary greatly depending on where the sun is. Temperatures from solar radiation can reach up to 121°C and drop as low as -233°C. Therefore, spacesuits must provide proper insulation and cooling.
The human body can survive for a period of time unprotected in the harsh vacuum of outer space, despite conflicting depictions in some popular science fiction novels or movies. Our skin and body are quite flexible. When exposed to such an environment, it will expand due to vacuum, but this expansion does not mean swelling like the balloon depicted in the movies. The effect consists of expanding within the body limits, as we see in people who do bodybuilding sports.
In addition to these reactions of our body, if we look at our vital values, there will be loss of consciousness after about 15 seconds due to the increase in oxygen deprivation. Space is seriously cold. In most films, these effects are described as sudden freezing. Whereas, rapid loss of body heat through thermal radiation or evaporation of liquids will not cause sudden freezing, since all heat must be lost.
In space, there are many different high-energy subatomic protons that would expose the body to extreme radiation. Although these compounds are in minimal amounts, their high energies tend to disrupt basic physical and chemical processes in the body, such as altering DNA or causing cancer.
exposure to radiation; It can cause problems in two ways. The particles can react with water in the human body to produce free radicals that break down DNA molecules or directly break DNA molecules. In summary, after 10-15 seconds without protection, loss of consciousness and death are inevitable in any case.
Physical Effects of Unprotected Area Exposure
The vacuum in space creates zero pressure, causing the gases and processes in the body to expand. To prevent the chemical processes in the body from overreacting, it is necessary to develop a suit of clothing that resists the pressure in space. We can define the change in pressure with what is called a diver’s smackdown. Namely; Hijacking is a situation that can be encountered not only at the surface after deep diving, but also at high altitudes.
Image-7. Underwater astronaut training. (Image Credit: NASA)
Holding your breath is one of the biggest dangers neither in scuba diving nor in space travel, pressure balancing/vacuum chambers or high altitude flights. Because uncontrolled Decompression can damage the lungs, the greatest danger arises here.
In fact, our skin is an incredible and natural garment that protects our entire body. Even if we are not aware of it, we are exposed to a pressure on Earth. Likewise, this natural clothing protects us up to a certain altitude in free diving or climbing, but of course there is a limit to this.
Human skin does not need to be protected from low-grade vacuum because we are covered with a gas-tight tissue, but its flexible nature can cause some changes. For this reason, we need to use a space suit, which is a respiratory support that fits tightly to our body, just like a diving suit.
Image-8. Orlan MK space suit. (Image Credit:NASA)
Spacesuit Types
The International Space Station is a joint effort of different countries and their space agencies. For this reason, astronauts use not only the suits developed by NASA, but also the space suits developed by Russia, called Orlan (in Russian, “Sea Eagle)” in outer space missions.
Orlan Dress
Orlan clothes are produced by the Russian company JSC NPP Zvezda. This company near Moscow conducts R&D studies on the designs and products of ejection seats, airplane escape slides, life jackets and fire extinguishers in airplanes, as well as space products.
The company is still active today, and perhaps some of its most important designs are the launch seats they developed for the Russian space shuttle Buran and helicopters. As it is known, helicopter propellers are an obstacle for vertical launch. However, in the system used in today’s Kamov Ka-50 armed attack helicopters, first the rotor blades are detonated with an explosive, then the canopies on the pilot cabins are thrown away and the seats are launched vertically with rockets. Although the firm has developed a suit called Strizk (meaning Swallow in Russian) for Buran space shuttle pilots, it has not had the opportunity to be used.
JSC NPP Zvezda was founded in the time of the USSR in 1952 to develop pressure suits and in-flight refueling systems for space exploration. With the acceleration of the space race, he started to design space suits (SK-1 type), which was also used by Yuri GAGARIN, only 8 years later in 1960.
After the clothing design named Berkut (“Golden Eagle” in Russian), produced in 1965, Orlan-E type clothing was developed and made available to cosmonauts.
