Flying to the Heavens
When a human being steps out of a spacecraft and into the vacuum of space, they are entering an environment that is instantly lethal. The vacuum is devoid of air, the temperature fluctuates wildly between extreme heat and freezing cold, and radiation is constant. To survive, an astronaut must wear a specialized garment that functions as a miniature, personalized spaceship. For the China National Space Administration, this technological marvel is the Feitian spacesuit.
The Feitian, which translates to “flying to the heavens,” represents a significant milestone in Chinese aerospace engineering. It is an Extravehicular Activity (EVA) suit, designed specifically to protect taikonauts while they work outside the pressurized confines of the Tiangong space station or the Shenzhou spacecraft. Unlike the lighter pressure suits worn during launch and reentry, the Feitian is a heavy, self-contained system capable of sustaining life for hours in the harshest environment known to humanity.
Developing an EVA suit is a challenge that few nations have mastered. It requires expertise in flexible pressure vessels, thermal regulation, life support miniaturization, and avionics. The existence of the Feitian demonstrates that China has joined the exclusive ranks of nations capable of independent extravehicular operations, a capability that is essential for the construction and maintenance of long-term orbital habitats.
Origins and Development
The path to the Feitian began with the initiation of Project 921, the Chinese crewed space program, in the early 1990s. While the early phases focused on launching humans into orbit and returning them safely, the long-term strategy always included the construction of a permanent space station. Building and maintaining such a station requires astronauts to perform work on the exterior of the structure. Consequently, developing an EVA suit became a high priority for the China Astronaut Research and Training Center.
Engineers faced a choice between developing a system entirely from scratch or leveraging existing technology. China chose a pragmatic approach by looking to Russia, a nation with decades of experience in space station operations. In 2004, China signed a contract with the Russian company Zvezda to purchase established Russian Orlan spacesuit systems. This agreement provided Chinese engineers with flight-ready hardware and training models, serving as a valuable technical baseline.
However, the Feitian is not a simple copy. While the external architecture bears a strong resemblance to the Orlan-M, the internal systems, electronics, and materials were developed indigenously. The project involved a massive national effort, with Chinese researchers developing new pressure-retention fabrics, digital communication systems, and control logic. The result was a suit that utilized the proven, robust mechanical design of the Russian suit but incorporated modern Chinese avionics and manufacturing techniques.
The Shenzhou 7 Mission
The world got its first look at the Feitian during the Shenzhou 7 mission in September 2008. This mission was dedicated to conducting China’s first spacewalk. The mission profile involved three taikonauts: Zhai Zhigang, Liu Boming, and Jing Haipeng.
The plan for the EVA utilized a mixed fleet of suits. Zhai Zhigang, the commander, wore the Chinese-built Feitian. Liu Boming wore one of the imported Russian Orlan spacesuit units to serve as a backup and assist Zhai from the airlock. This strategy provided a safety net, ensuring that if the new domestic suit encountered issues, a proven backup was available.
On September 27, 2008, Zhai exited the orbital module of the spacecraft. The event was broadcast live, showing the white Feitian suit against the black backdrop of space. Zhai waved a Chinese flag and retrieved a test sample from the exterior of the ship. The spacewalk lasted roughly 22 minutes. While brief, it validated the suit’s design and performance. The Feitian maintained pressure, provided breathable oxygen, and allowed sufficient mobility for the taikonaut to complete the assigned tasks. This success marked China as the third nation, after the Soviet Union and the United States, to independently demonstrate spacewalk capability.
Engineering Architecture
The Feitian is classified as a semi-rigid suit. This design philosophy differs from the soft suits used in the early days of space exploration. The core of the suit is a hard upper torso, essentially a rigid cuirass made of aluminum alloy or composite materials. This hard shell provides structural integrity and serves as the mounting point for the helmet, arms, and lower body assembly.
The rigid torso offers several advantages. It does not change shape when pressurized, which stabilizes the geometry of the suit and makes the placement of controls and displays predictable. On the chest area of the torso, a display and control module allows the taikonaut to monitor vital signs, suit pressure, and consumables. The text on these controls is often reversed, designed to be read via a wrist-mounted mirror, a clever low-tech solution to the problem of restricted downward visibility.
Attached to this hard torso are the soft limbs. These are not simple cloth sleeves but complex, multi-layered engineered systems. The innermost layer is a rubberized bladder that retains oxygen and pressure. Over this lies a restraint layer, typically made of a high-strength synthetic material like Dacron or Kevlar, which prevents the bladder from ballooning and defines the shape of the limb. The outermost layer is the Thermal Micrometeoroid Garment (TMG). This multi-layered cover protects the inner suit from abrasion, reflects solar heat, and acts as a shield against tiny, high-velocity space debris.
Life Support Systems
The backpack of the Feitian suit houses the Portable Life Support System (PLSS). This unit is the functional heart of the suit, containing the machinery required to keep the astronaut alive. The PLSS is hinged and acts as the entry door for the suit, a design feature adopted from the Russian Orlan.
Oxygen is stored in high-pressure bottles within the backpack. The system regulates this oxygen to maintain a suit pressure of approximately 40 kilopascals (5.8 psi). This pressure is significantly lower than sea-level atmospheric pressure (14.7 psi). The lower pressure is necessary to prevent the suit from becoming too stiff. If the suit were pressurized to sea level, it would be as rigid as an inflated car tire, making movement impossible. The 5.8 psi setting strikes a balance, providing enough oxygen for the human body while allowing the joints of the suit to bend.
Carbon dioxide removal is another essential function. As the astronaut breathes, carbon dioxide builds up in the helmet. The PLSS circulates the air through a canister containing lithium hydroxide, which chemically reacts with the carbon dioxide and removes it from the airflow. Later versions of the suit for the space station may utilize regenerable metal oxide systems, which can be cleaned and reused, reducing the logistical burden of resupply.
Thermal control is managed through a Liquid Cooling and Ventilation Garment (LCVG). This is a form-fitting underwear layer threaded with a network of flexible tubing. Cool water is pumped through these tubes, picking up body heat generated by the astronaut. The warm water flows back to the PLSS, where it passes through a sublimator. In the sublimator, the water is exposed to the vacuum of space through a porous plate. The water freezes and sublimates (turns directly to gas), taking the heat away with it. This system allows the suit to maintain a comfortable internal temperature regardless of whether the astronaut is in direct sunlight or the freezing shadow of Earth.
Mobility and Manipulation
Movement in a pressurized suit is physically demanding. Every time an astronaut bends an elbow or closes a hand, they are fighting against the internal air pressure that wants to force the suit into a straight, expanded shape. To mitigate this, the Feitian utilizes convoluted joints – bellows-like structures at the shoulders, elbows, hips, and knees. These joints maintain a constant internal volume as they bend, reducing the work required to move.
The shoulder joints use complex bearings that allow for rotation, giving the taikonaut the ability to reach across their chest or above their head. The lower body of the Feitian is designed primarily for anchoring. On the space station, astronauts do not walk; they float. The legs are used to lock into foot restraints, providing a stable base while the astronaut works with their hands. Consequently, the leg mobility is sufficient for climbing and positioning but is not optimized for walking on a planetary surface.
Gloves are the most intricate and personalized component of the suit. The Feitian gloves must protect the hands while allowing for enough dexterity to manipulate small tools, tether hooks, and electrical connectors. They feature a rotary joint at the wrist and textured fingertips for grip. Taikonauts often report that hand fatigue is the limiting factor in spacewalks, as the gloves constantly resist closing. The gloves also include fingertip heaters to prevent the extremities from getting too cold during shadowed passes.
Operational Procedures
Entering the Feitian suit is a distinct process due to its rear-entry design. Unlike the American Extravehicular Mobility Unit (EMU), which requires the astronaut to put on pants and then rise into a hard upper torso, the Feitian allows the astronaut to step into the suit from the back. The backpack swings open like a refrigerator door. The taikonaut, wearing their liquid cooling garment, climbs into the hatch, inserts their legs and arms, and then seals the backpack shut behind them. This design allows for rapid donning and doffing, and it can technically be done without assistance, though crew help is standard procedure.
Before exiting the airlock, taikonauts must undergo a pre-breathe protocol. Because the suit operates at a lower pressure than the space station, there is a risk of decompression sickness, or “the bends.” Nitrogen dissolved in the blood can form bubbles if the pressure drops too quickly. To prevent this, taikonauts breathe pure oxygen for a set period before the spacewalk, flushing nitrogen from their systems. The exact duration depends on the pressure drop and the specific protocol used, but the Feitian’s operating pressure allows for a shorter pre-breathe period compared to lower-pressure suits.
Evolution for the Space Station
Following the initial success of Shenzhou 7, the Feitian suit underwent a significant upgrade cycle to prepare for the Tiangong space station era. The first-generation suit was designed for a short, experimental sortie. The second-generation suit, introduced on the Shenzhou 12 mission in 2021, is a workhorse designed for regular, intensive construction tasks.
The operational lifespan of the new suit has been greatly extended. While the original was rated for a limited number of uses, the new Feitian is designed to remain on the space station for years, capable of supporting multiple EVAs with on-orbit maintenance. The endurance of a single spacewalk was increased to roughly eight hours, giving taikonauts more time to complete complex installations.
Ergonomics were improved based on user feedback. The helmet field of view was optimized, and the joint bearings were refined to reduce friction. The suit also integrated a more advanced helmet camera system, providing high-definition video feeds to mission control. This visual link allows experts on the ground to see exactly what the taikonaut sees, offering real-time guidance during intricate procedures.
Another significant advancement was the sizing capability. The new suits are more adjustable, accommodating a wider range of body heights and types. This was demonstrated when Wang Yaping performed her historic spacewalk during the Shenzhou 13 mission, utilizing a suit that had been configured for her smaller frame compared to her male colleagues.
Comparative Analysis
To understand the Feitian’s place in aerospace history, it is helpful to compare it with its contemporaries. The following table outlines key differences between the Feitian and the American EMU.
| Feature | Chinese Feitian | American EMU |
|---|---|---|
| Entry Method | Rear-Entry (Backpack door) | Waist-Entry (Pants/Torso connect) |
| Structure | Semi-rigid (Hard torso, soft limbs) | Semi-rigid (Hard torso, soft limbs) |
| Operating Pressure | ~5.8 psi (40 kPa) | 4.3 psi (29.6 kPa) |
| Pre-breathe Requirement | Shorter duration | Longer duration (due to lower pressure) |
| Sizing Philosophy | One-piece adjustable | Modular components (S, M, L, XL parts) |
| Design Origin | Derived from Russian Orlan | Indigenous US design |
The comparison highlights different engineering philosophies. The American EMU focuses on maximizing mobility through lower pressure, at the cost of a longer pre-breathe preparation. The Feitian prioritizes operational simplicity and rapid egress capabilities through its rear-entry design and slightly higher operating pressure. Both systems have proven to be highly effective for microgravity construction work.
Future Lunar Applications
The current Feitian suit is optimized for microgravity. It is excellent for floating outside a space station but would be unsuitable for walking on the Moon. The Chinese Lunar Exploration Program has announced plans to land taikonauts on the lunar surface by 2030, necessitating the development of a completely new generation of spacesuit.
A lunar suit faces distinct challenges. It must deal with the abrasive, electrostatically charged lunar dust that can jam mechanisms and tear fabrics. It requires a lower torso designed for walking, kneeling, and recovering from falls in one-sixth gravity. Thermal management becomes more difficult due to the heat retention of the lunar surface itself.
China has already begun unveiling prototypes for this lunar suit. While it will likely retain the rear-entry architecture that has proven so successful with the Feitian, the limbs and joints will be radically different. The legacy of the Feitian provides the foundational knowledge – materials science, life support integration, and pressure sealing – that makes this next leap possible.
Summary
The Feitian spacesuit stands as a testament to the rapid advancement of China’s space capabilities. Starting from a foundation of imported technology, Chinese engineers have mastered the complex art of life support and pressure suit design. The suit has evolved from a test article flown on Shenzhou 7 into a reliable, reusable tool that is central to the operations of the Tiangong space station.
By enabling routine spacewalks, the Feitian has allowed China to assemble a permanent outpost in orbit, repair scientific instruments, and test technologies for future exploration. It is more than just a protective garment; it is the vehicle that allows humanity to extend its reach beyond the capsule and interact directly with the cosmos. As China looks toward the Moon, the lessons learned from the Feitian will serve as the bedrock for the next generation of explorers who will leave their footprints in the lunar dust.
