The Development and Current Situation of American In-cabin Spacesuit

【Abstract】 This paper systematically reviews the history of the development of the American spacesuit, and describes the latest commercial SpaceX spacesuit in the United States. SpaceX spacesuit by the private space exploration company (SpaceX) design and production completed, this spacesuit and traditional spacesuit focus on performance and ignore the appearance of different, in the appearance of a great breakthrough. However, the SpaceX spacesuit is only suitable for use within the spacecraft due to functional design limitations. By analyzing the design features of the SpaceX spacesuit, such as the appearance and fabric, combined with the trend of The Times, the future development of spacesuit is the key direction of high-tech multi-function and fit.
【Keywords】 spaceX space suits; In-cabin spacesuits; appearance design; the details show

0 Preface
For thousands of years, human beings have always been interested in space and have never stopped exploring. If human beings want to survive in the space environment, they must use related equipment to maintain the basic needs of life and provide a living environment for life. In addition to spacecraft, space suits are very important for astronauts. As the clothing worn by astronauts during their missions, space suits have functions similar to those of mini-spacecraft. Spacesuits can be divided into three categories according to their functions, namely（IVA spacesuit）, extravehicular spacesuit (EVA spacesuit) and（IEVA spacesuit） . The development of in-vehicle and extra-vehicle one-piece space suits is limited by early technological development, and now the extra-vehicle and in-vehicle space suits have been developed separately. The space suit in the cabin is also called the emergency rescue space suit. It is mainly used in the stages of launch and return. The space suit is used to ensure the oxygen required for astronauts to breathe and maintain the necessary survival pressure to ensure that the astronauts lose pressure in the cockpit. safety of life.
Looking back at the history of the development of human spacesuits in the past 100 years, spacesuits inevitably give people a clumsy and heavy feeling. This is mainly related to the nature of the aerospace industry. The traditional spacesuit design takes safety and functional requirements as the core starting point, and the cost is high, and the “appearance aesthetics” is the second priority. But with the advancement of the times and the commercialization of the space industry, designers will naturally think about how to make the appearance of space suits attractive. This paper makes a detailed statement on the functional reform of the SpaceX spacesuit as a commercial design clothing appearance, in order to provide some ideas for the development of future spacesuits.

1 In-cabin space suit
1.1 U.S. in-cabin spacesuits
In the early 1830s, American high-altitude pilot Persian presided over the development of the world’s first high-altitude pressure suit™, which laid the prototype of the future space suit research and development. In the 1860s, inspired by the high-altitude jet pressure suit of the U.S. Navy, the Mercury space suit was born. From the perspective of the development process of the US space suit, the development of the US space suit is influenced by the mission.
Beginning in 1981, NASA (National Aeronautics and Space Administration) began to use a new generation of extravehicular space suits. Due to the high cost of space suits, the American space suits no longer adopted tailor-made methods, but adopted Modular design ideas. That is, the number is determined through specific tasks, and by combining CEI (Contract End I-tems) modules of different sizes, the astronauts are finally provided with almost tailor-made clothing.
This method not only saves money significantly, but also facilitates astronauts to replace clothing components during long-term exploration missions. Table 1 summarizes the characteristic information of the major US in-vehicle spacesuit systems in different periods.

1.2 SpaceX spacesuit
Generally speaking, although different types of space suits have different fabrics, comforts, overall functions and appearance designs, most of them are bulky and complicated in appearance. With the development of the times, space suits are also facing major changes in appearance.
The spacesuit in the SpaceX cabin is also known as the “Star Man” spacesuit. In 2018, SpaceX used a dummy model called “Star Man”, wearing a spacesuit that only has shape but not function, and flew into space on a launch vehicle. The SpaceX spacesuit, as the first commercial cabin spacesuit to enter space, has undergone major changes in design. In 2015, SpaceX said it would develop a spacesuit. In 2017, Elon Musk published the first official photo of the SpaceX spacesuit on his private account for the first time. He pointed out that the spacesuit has been stress tested, but it is very rare to require the spacesuit to be functional and beautiful at the same time. matter. Therefore, in this process, they adopted a “reverse engineering” design method: first design the appearance of the spacesuit, and then consider how to meet the functional and protective requirements of air travel. It took Musk and Fernandez four years to finally complete this “Star Man”.
In 2020, Bob Behnken and Doug Hurley wore “SpaceX Dragon flight suits” and carried the Crew Dragon into space. And this is the first public appearance of the spacesuit. SpaceX spacesuits are tailored for astronauts to be functional, lightweight, and aesthetically pleasing, as well as provide protection against possible depressurization.

2 SpaceX spacesuit functional design
2.1 Structural Design
Structural design is the core of the spacesuit in the cabin. The SpaceX spacesuit consists of pressure suits, helmets, gloves, ventilation and oxygen supply components and some accessories. It is a functionally integrated clothing. Its structural shape is similar to that of traditional spacesuits, and it adopts a “soft” type structure in which the head and torso and limbs are connected together, and an open ventilation and oxygen supply method.
SpaceX spacesuits are custom-made for astronauts, and helmets are also custom-made using 3D printing technology. Customization allows both garments and helmets to perfectly fit the wearer’s body shape and size. The helmet is equipped with a communication system and control valves connected to various parts of the body. There is a button on the side of the helmet that controls the opening and closing of the mask. The helmet is attached to the mask, but traditional helmets have long been bolted to restrict the wearer’s head movement, resulting in the wearer only looking straight ahead and not looking to the side. Therefore, in the past, astronauts called this situation the “crocodile head” effect.
To this end, Jose Fernandez changed the upper neck part of the spacesuit helmet from bolts to hinges, which made these flight suits lighter and, at this time, provided the astronauts with a better field of view. The design of the SpaceX spacesuit offers a new way to solve this conundrum.
Different from traditional spacesuits, the “Xingxia” spacesuit has a flat appearance, because the designer uses the “hiding” formula to hide the external hoses, wires and raised knobs on the surface of the clothes. , The life support system interface and other line interfaces such as air and power connections are hidden by the rectangular cover above the knee of the right leg and will not be exposed on the surface of the garment. And the seat is equipped with clothing connection pipes, which greatly facilitates the operation of the astronauts.
For spacesuits, improving fit, flexibility, and ease of putting on and taking off can effectively guarantee its ergonomics. In terms of adaptability, SpaceX maximizes the adaptability of space suits through customized strategies, so that astronauts can carry out activities comfortably and flexibly when necessary. In terms of flexibility, the flexibility of spacesuit joints and gloves is the primary factor that restricts the ability of the suit to operate. The activities of astronauts wearing spacesuits are mainly limb activities, and clothing will have certain constraints on human activities. Therefore, the design of the joint is particularly important. The knee part of the SpaceX spacesuit has a suitable margin through the pleated design, which not only facilitates the bending of the human leg, but also makes it more concise and beautiful. In addition, the convenience of putting on and taking off the spacesuit is one of the basic requirements for the spacesuit.

2.2 Appearance design “Xingxia” belongs to the space suit in the cabin, which is only worn by the astronauts in the cabin when the manned spacecraft emerges. If the spacecraft is in danger of gas leaks or sudden changes in air pressure during flight, it must be able to protect the air pressure balance of the astronauts in the cabin. In addition, during the journey, astronauts need to wear the spacesuit in the cabin to move in the cabin, so the spacesuit in the cabin should not be too bulky and should ensure the flexibility of the wearer. Therefore, compared with extravehicular spacesuits, in-vehicle spacesuits are generally lighter, and the appearance is easier to make into a compact design.
Compared with the traditional American spacesuit, because to ensure the comfort of the astronauts when they bend their bodies, they will be designed with sufficient margins, which directly causes the astronauts to appear heavy and bloated when standing. In general, SpaceX’s spacesuit is different from the ergonomic design, and the appropriate margin design makes the clothing look neat even when the astronaut is upright, and is influenced by pop culture and science fiction works in interstellar travel. Influenced by the shape, the clothing is mainly black and white as a whole, and the overall design takes into account the ability and fashion. The black and gray pieces on the side can visually modify the body shape.
It is aerodynamically designed with a dividing line extending from the shoulder blades to the upper part of the knees. The sleek black-and-white look of the SpaceX spacesuit makes for a streamlined, stylish and visually striking look. Visually, the SpaceX spacesuit is an upper and lower suit with a separate helmet and shoes. But in fact it is a one-piece design, the helmet is connected to the body, and the feet are made of black fabric to make the shape of boots, which are part of the body itself. As a one-piece suit, it not only has a streamlined and lightweight appearance, but also can meet the needs of the wearer’s activities in the cabin, and can also ensure the safety of the wearer’s life in the cabin. As shown in Figure 5, the shoulders of the SpaceX spacesuit have straight and smooth lines in appearance, and the body-fitting design makes the shoulders more fashionable.

2.3 Fabric selection
Space suits face a series of functional challenges, and the first problems to overcome are pressure and temperature. As altitude increases, air pressure and air temperature will decrease significantly. This puts forward requirements for the design of functional fabrics of space suits, that is, the core point of the design of space suits is the protection requirements for the decompression environment.

2.3 Fabric selection
Spacesuits face a series of functional challenges, and the first problems to overcome are pressure and temperature. As altitude increases, air pressure and air temperature will decrease significantly. This puts forward requirements for the design of functional fabrics of space suits, that is, the core point of the design of space suits is the protection requirements for the decompression environment.
EMU (extravehicular mobility unit) is a new type of space suit, which is developed on the basis of the Apollo space suit and consists of a pressure suit and a life support system. Due to its unique environmental characteristics, pressure clothing needs to be composed of multiple layers. Similarly, in order to cope with the environmental changes in space, the “Xingxia” spacesuit uses a similar fabric to the international active-duty extravehicular exploration device EMU, which also has a multi-layer structure.
The outer layer of the spacesuit uses a variety of polymer materials including “Nomex” and “Teflon”. “Nomex” series products have superior high temperature resistance, flame retardant, non-toxic, and better mechanical properties. The “Teflon” material is also a material that can withstand high temperatures and allow for quenching, quenching, and high pressure. Both materials are developed by DuPont and are widely used in aerospace and other national economic fields. These special materials make “Xingxia” fireproof, waterproof, dustproof and oil proof, and also resistant to wear and tear. The white part of the surface is made of DuPont’s “Teflon” material, which was used for the outer layer of the “Apollo” spacesuit. Teflon is widely used, not only for soft materials such as textile fabrics, but also for various hard materials. The black part also uses DuPont’s “Nomex” material. This material is commonly used in racing suits, and also functions similarly to DuPont’s “Kelvar” material once used on NASA’s orange spacesuits.
The main function of the construction and material of the inner multi-layer material is to ensure the balance of air pressure inside and outside the wearer’s body. In the case of pressure imbalance in the cabin, the safety of the wearer’s life can be guaranteed. Back in 2017, the suit passed the rigors of double vacuum pressure.
The gloves and bodice of the SpaceX spacesuit are also tailored in such a way that they become part of the overalls. Intelligence and automation are the trend of clothing development, and spacesuits are technology-integrated clothing. SpaceX spacesuits use glove touch screen technology to match existing touch screen technology.
technology, so that the wearer can control the spacecraft through its interaction with the touch screen. The commonly used touch screen gloves refer to the special gloves used to operate capacitive touch screen products in winter, which realizes many functions such as protection and technology. From the design point of view, the inner layer of the touch screen glove is made of antistatic fiber. Through the test of charge amount and yarn test, it meets the charge amount of the touch screen and the inspiration degree of the touch screen glove 10, and the unique weaving is carried out through the computer to complete the space suit. The final form of the glove. As a result, the spacesuit is more automated, which also provides higher safety for astronauts to enter space.
2.4 Functional Innovation
A major innovation in SpaceX’s spacesuits is that SpaceX’s spacesuits dissipate heat from the astronauts’ bodies through air cooling. Prior to this, NASA’s current EMU used water-cooled heat dissipation. The water-cooled tube was adsorbed on the astronaut’s skin to absorb sweat to keep the body dry and absorb heat to keep the astronaut’s body temperature lower than the core temperature of the human body. Air-cooled heat dissipation has higher safety, not only can it avoid water damage to astronauts, but switching to air cooling means that the cooling medium is harmless in the event of leakage. But at the same time, the use of air-cooled spacesuits will increase power consumption, because air is less efficient at removing heat than water, and the pump requires more power. 3 Summary
With the development of the times, industrial changes have brought about major changes in space suits. Space suits have gradually changed from the traditional “protection and functionality as the mainstay, supplemented by aesthetics” to “both functionality and aesthetics”.
In this regard, SpaceX has promoted the development of spacesuits in the cabin. Although it may only be a small step forward, it is not a historic change, but it is a small step that has been realized and has practical significance, and may herald future trends. The beginning of change. For the innovation carried out by SpaceX, all aspects can not only learn from its design ideas, but also promote the continuous development of the spacesuit industry and the industry.