Buzz
Astronauts rely on their suits to survive the extreme conditions of space, but the journey from concept to reality is filled with fascinating details. Lindsay Aitchison, a Space Suit Engineer at NASA’s Johnson Space Center, shares the intricate process behind creating these life-saving garments.
1. Crafting space suits demands a unique combination of skills.
These skills might surprise you. According to Aitchison, the role blends analytical thinking with innovation. “Precision is key, especially when creating detailed test plans,” she explains. “Working with human test subjects means gathering feedback on subjective factors like comfort. Defining and engineering comfort requires both technical expertise and creative problem-solving.” Aitchison emphasizes how cross-disciplinary inspiration can lead to breakthroughs in space suit technology.
2. Suits are tailored to their specific missions.
Aitchison explains that NASA engineers begin by addressing two critical questions to shape the suit’s design: Where is the mission headed, and what tasks will astronauts perform?
The destination is the first consideration, categorized into micro-gravity environments or planetary surfaces, which dictate the level of mobility required. Engineers also evaluate factors like radiation levels, temperature extremes, and the potential threat of micro-meteoroids.
The next step involves analyzing the astronauts’ activities. Will they be maneuvering in micro-gravity or walking on a planetary surface? Will they use tools, carry equipment, or rely on upper-body strength? Autonomy is another key factor. “On distant planetary surfaces, we’re developing technologies for autonomous EVAs,” Aitchison notes, “while space stations allow for closer collaboration with flight control teams, reducing the need for self-reliance.”
3. Innovative Suits Demand Advanced Footwear.
EMU suit; photo courtesy of NASA.
The Extravehicular Mobility Unit (EMU) suit is the most recognizable, designed for micro-gravity environments where astronauts rely on their hands for movement. It enables repairs and upgrades to the International Space Station (ISS), telescopes, and other structures during spacewalks, requiring enhanced mobility in the shoulders, arms, and hands. "The lower section provides stability, creating a solid platform when working from a robotic arm," Aitchison explains. "If it’s too flexible, tasks become nearly impossible to complete."
However, newer suits like the Z-2 are being developed for planetary exploration, shifting the focus to waist, hip joints, and footwear. "This marks the first time since Apollo that we’ve needed a walking boot," Aitchison notes. "Walking in varying gravity fields alters your gait, so we’re designing boots tailored to Martian or Lunar gravity. It’s a stark contrast to the EMU’s rigid-soled boot."
To determine the ideal footwear, Aitchison conducted walking tests in 2008 using suits adjusted to simulate different gravity levels. "We offloaded the suits to mimic 3/8 or 1/6 gravity on a treadmill, with a rig supporting the suit’s weight," she says. Motion capture markers on the lower body helped analyze foot, ankle, and hip movements. "We observed a galloping motion in lower gravity, which guided us in balancing flexibility and stiffness in the sole to optimize movement."
While designs are still under review, Aitchison mentions a hiking boot sole as a leading candidate. "It’s rigid in the forefoot but offers mid-foot flexibility, making kneeling tasks more manageable."
4. The aim is to reduce the weight of new suits.
Apollo suit; photo courtesy of NASA.
The EMU tips the scales at 300 pounds, though astronauts don’t feel this weight in microgravity. In contrast, the Apollo suits, including backpacks, weighed 180 pounds on Earth and only 30 pounds on the Moon. However, Aitchison notes, "they lacked significant mobility." The challenge now is to create lighter suits without sacrificing flexibility. "Adding mobility involves incorporating rigid components like bearings, which improve functionality in pressurized suits but increase weight," Aitchison explains. "We’re exploring lightweight solutions, such as titanium, which reduces bearing mass by 30 percent, and advanced composite materials for the upper torso, hips, and brief sections."
The new Z-2 will be approximately 20 pounds lighter than the EMU. "It might not sound like much," Aitchison admits, "but we’re also introducing lower torso capabilities that were previously unavailable."
5. The design process begins by experimenting with older prototypes.
After determining the mission’s location and objectives, the design phase begins. The Advanced Space Suit Group utilizes prototypes from the past 30 years, including shuttle and Apollo-era suits. "We begin by testing these suits to evaluate their features," Aitchison explains. "We analyze shoulder designs for specific tasks, hip and boot configurations, and entry styles. Should a zipper be included? These elements help us identify the best components for a given mission."
6. NASA designs the suits, but private manufacturers handle production.
Two-dimensional rendering of the "Technology" version of the Z-2 suit. Photo courtesy of NASA/Johnson Space Center.
While testing and initial design sketches are done in-house, NASA collaborates with private companies for manufacturing. "We define the requirements and provide the overall concept, then vendors build the suits to our specifications," Aitchison states. Engineers focus on one suit at a time, and since the Constellation program began in 2005, they’ve received new prototypes every three to five years.
7. Some suit components are meticulously hand-sewn.
During the Apollo era, space suits were hand-sewn. Despite technological advancements, this method has not become obsolete.
A breakdown of space suit construction: The innermost layer, known as the bladder, is described by Aitchison as "essentially a balloon that retains air." This layer is sealed and welded using machines. Above it lies the restraint layer, which provides structural integrity. "It ensures the bladder bends correctly and absorbs the suit’s loads, protecting it from excessive force during movements like bending an elbow," Aitchison explains.
The restraint layer remains hand-stitched. "A dedicated room houses sewers equipped with specialized machines for different suit sections, capable of precision stitching down to a 16th of an inch," Aitchison notes. "They’re incredibly skilled." The sewers select threads based on the required strength or elasticity for each part.
8. Yet, they remain at the forefront of innovation.
The Z-2 suit was developed using 3D human laser scans and 3D-printed hardware, marking the first application of such technology in suit sizing and design.
9. Suits are permitted to have minor leaks.
However, the leakage must not exceed 100 SCCM (standard cubic centimeters per minute). Aitchison explains that each component undergoes rigorous testing during fabrication to ensure it meets design standards. Seam allowances are precisely measured, and samples are stress-tested to verify strength. "Testers use machines to determine the force required to tear the seam or fabric," Aitchison notes.
Once the suit is assembled, it undergoes further testing. "We conduct structural and linkage tests by inflating the suit to 1.5 times its operating pressure—4.3 PSI for spacewalks—to ensure it’s robust and free from leaks or seam distortions," Aitchison says. "After the structural test, we return to normal pressure and perform another leak check."
10. Space suits are not custom-made.
Creating individual suits for each crewmember is impractical. Instead, suits are built using a modular system, contributing to their bulkiness. "Mix-and-match components are slightly larger to accommodate a broader range of body types," Aitchison explains. "We use small, medium, and large components to fit different crew sizes, simplifying logistics and ensuring redundancy on the space station." (Currently, the station has enough parts for four complete EMU suits and numerous replacements.) This modular approach also streamlines repairs, allowing engineers to replace individual parts rather than constructing an entirely new suit.
11. Designers concentrate on one suit at a time.
Considering the extensive testing and design requirements, it’s no surprise that engineers focus on a single suit at a time. "We aim to identify what works and what doesn’t before moving to the next version," Aitchison explains. From initial concept to prototyping and testing, "developing a new suit is a lengthy process, taking over a year." Fabrication of the Z-2 suit begins this month, with completion expected in August, followed by rigorous testing.
12. Astronauts wear multiple layers before donning their suits.
The scene in Gravity where Sandra Bullock removes her EMU suit to reveal minimal clothing is entirely fictional. Real astronauts wear several layers beneath their suits.
The first layer is the Maximum Absorbency Garment (MAG), essentially a high-absorption diaper. "This serves as the waste management system," Aitchison states. Over this, astronauts wear form-fitting comfort undergarments, which help regulate body temperature. "The liquid cooling garment ensures comfort by circulating cold water through tubes across the body, removing heat and releasing it into space," Aitchison adds.
13. Pressurized suits can be created in multiple ways.
Photo courtesy of MIT
Maintaining pressure is essential for astronauts to function in space, with a minimum of 2.5 PSI required for vital processes like lung inflation and blood circulation. (A slightly higher pressure is even more effective, Aitchison notes.) This can be achieved through gas-pressurized suits, like those used by NASA, or mechanical counter pressure (MCP) suits, such as the one developed at MIT (pictured above). "MCP suits resemble a very snug wetsuit," Aitchison explains. "They must apply the same pressure as gas by directly compressing the skin."
In the 1970s, NASA explored mechanical pressure suits, including Dr. Paul Webb’s Space Activity Suit. While effective, these suits required hours and multiple assistants to put on. MCP also faces challenges in maintaining even pressure across the body. "Areas like the palms, elbows, knees, and groin change shape with movement, so materials must adapt to these contours," Aitchison says. "Developing such technology for exploration in the next 5 to 10 years is complex, which is why gas-pressurized suits remain the preferred choice."
14. The Z-2 Will Be Relatively Compact.
Z-1 Space suit. Photo courtesy of NASA/Johnson Space Center.
The Z-2 will be one of the most compact exploration suits ever created. "The Z-1 featured a large 13-inch dome, ideal for larger men but unnecessarily bulky for smaller women," Aitchison explains. "By reducing its size, we also streamlined the rest of the suit. We analyzed the current astronaut population and designed the Z-2 to accommodate individuals in the bottom 40 percent of the size range, from the 5th percentile female to the 99th percentile male—a significant variation."
15. You can help decide its appearance.
Z-2 renderings courtesy of NASA/Johnson Space Center.
NASA’s previous suit, the Z-1, bore an unintentional resemblance to Toy Story’s Buzz Lightyear. "The design sparked widespread discussion, and we wanted to capitalize on that interest," Aitchison says. "To engage the public, we created a voting website where people can choose the Z-2’s look and learn more about its development."
Collaborating with fashion students from Philadelphia University, the engineers explored diverse design themes for the suit, a departure from their usual process. "The students brought a fresh perspective rooted in fashion," Aitchison notes. "We used mood boards to capture various themes, such as patriotic, traditional, or science and technology. Starting with 12 concepts, we refined them to best represent our vision." This collaboration resulted in three final designs: Biomimicry, Technology, and Trends in Society. Cast your vote for your preferred design here.
While the designs are currently aesthetic, Aitchison envisions practical uses for features like bioluminescence in the Biomimicry suit. "On planetary surfaces with day-night cycles, bioluminescence could serve as a unique crew identifier," she explains. "Currently, we use colored fabric stripes to distinguish crew members. Bioluminescence could offer a functional and innovative alternative for identification in such environments."
