As the Artemis II astronauts prepare for the most dramatic and potentially dangerous part of their mission — reentry into Earth’s atmosphere — the eyes of the world will be on the Orion capsule and the people inside it. Getting glimpses into the capsule during the mission, the public has been able to observe the features of the astronaut’s lives, from the screens where they receive messages from Earth to the bathroom they use and how it was fixed when it broke.
Every single piece of technology in the Orion capsule has been designed not just to withstand the epic G-forces of launch and landing, but also to optimize for human interfacing. And those human factors — the personal, sometimes intangible feeling of interacting with technology that just works in a way that is intuitive and enhances daily life — are now at the forefront of spacecraft design.
“A lot of design is actually organization of information.”
The first and foremost principle of human factors has always been safety. That means safety for the crew, and secondarily, safety for the spacecraft as well. The capsule undergoes rigorous testing to ensure that it can withstand the tremendous forces of reentry, but so do seemingly mundane objects, which become crucially important.
When you are preparing to smash into the atmosphere at a speed of almost 25,000mph, you better make sure that you’re sitting in a well-designed seat, for example.
“Seats can save lives,” says Olga Bannova, director of the space architecture graduate program at the University of Houston. Seats must handle massive impact loads while transferring as little force as possible to the astronauts sitting in them, and good seat design is considered the most effective way to prevent injuries during landing, especially during emergencies. Seats need to be comfortable, even when astronauts have extreme G-forces pushing them into the seat during reentry, but they also need to provide support to delicate human frames while allowing natural movements.
Orion’s seats are “designed to accommodate nearly 99 percent of the human population,” according to NASA, and are adjustable to account for individual variation and to allow movements to reach important controls even when wearing a pressure suit. They can also be dismantled and packed away if needed, to give the crew more room to work in the small capsule space.
These same G-forces that act on the seats make it difficult for astronauts to even lift their hands to touch a control screen at times, so the Artemis II astronauts will use control devices like the rotational hand controller, which looks a bit like a joystick, or the cursor control device, which has similar inputs to a gamepad, in order to interact with the spacecraft even when larger physical movements are difficult or impossible.
Human factors go beyond just covering safety basics. Designers are increasingly considering psychological factors like comfort and privacy for space missions, such as giving astronauts their choice of sleeping options. Artemis II commander Reid Wiseman said this week, for example, that he likes to sleep under Orion’s displays to be nearby in case anything goes wrong, but his fellow astronaut Christina Koch prefers to sleep “suspended like a bat,” while pilot Victor Glover likes to tuck himself into a small nook near the ceiling.
And as anyone who has ever had a roommate knows, it can be hard to live in close proximity to the noises, odors, and movements of another human being. That’s why designers consider acoustics and odor control when creating interiors, as well as giving astronauts small pockets of privacy where it’s possible to do so. That means that flight hardware needs to pass acoustic testing to ensure it isn’t too noisy and distracting, and creating an odor control system for Orion’s toilet — though this particular bit of hardware had a few teething issues.
This kind of attention to user experience isn’t just window dressing, but rather a key part of getting the best out of the astronauts. The approach is “thinking about comfort as a requirement for productive work and for fulfilling mission goals,” Bannova said. Astronauts are highly skilled and extremely resilient, she pointed out, but “we don’t need to squeeze them!”
“Human factors are now a design requirement, not just a nice-to-have,” says Sebastian Aristotelis, lead architect at SAGA, a company that designs space habitats and technology experiments which have flown on the ISS.
For him, a well-designed and thought-out environment is not just a secondary consideration but a psychological boost as well: “I would argue that it’s actually an important part of the safety metrics. I feel more safe if I’m in a capsule that is well designed because it shows that there’s been enough resources, that you have not skipped any functions or requirements of making this capsule a reality.”
Exactly what good design entails is somewhat subjective. It includes, for example, whether you like the look of exposed fasteners, or whether you’d prefer a smoother and more minimal surface. Those design differences are apparent when comparing the NASA Orion capsule with the SpaceX Crew Dragon interior. These two craft have somewhat different functions so they aren’t entirely comparable, but you can clearly see a more pragmatic engineering approach in Orion, while there’s a more vertically integrated, branded look to the Dragon.
There are advantages to a simplified design. You don’t want dangling wires that could get in the way and impede movement in an emergency. If an environment is visually busy, it’s easier to misplace an important tool. But you also want equipment to be accessible and easy to maintain, with its function immediately obvious. Whether you’re going for a more functional or more sleek look, everything in a spacecraft “needs to be simple and pragmatic, and clean, and easy to take apart and put back together,” Aristotelis says.
Achieving this kind of intuitive design requires working closely with astronauts themselves.
Bannova agreed, linking the principles of design on Earth to those for space: “Architecture exists for people. We design for clients. If it’s not designed well for people to live, work, communicate, socialize, do whatever they need to fulfill their cultural needs, then it’s not good architecture.”
Another prominent difference between the Orion and Dragon capsules is the approach to information display and interaction. Dragon has three large touchscreens as its main display system, while Orion has many more buttons, switches, and inputs.
Partly this is about the differing functions of the vehicles, as Dragon is specialized for low Earth orbit missions such as ferrying astronauts to the ISS, while Orion must also tackle the challenges of deep space exploration. That means Orion needs more space for cargo capacity to make room for extra supplies for longer missions, as well as the flexibility to carry more than four astronauts if needed. But the different visual appearances of the capsules also represent differing approaches to the problem of what information to display to a crew.
At first glance it might seem sensible to give the crew access to as much information about the spacecraft as possible, allowing them to pick out whatever data they need at any moment. But too much information can be overwhelming, and can make it harder to determine what’s truly important for a given situation.
Designers help here too, by creating interfaces that give the right information at the right time. “There is a safety element to it, because a lot of design is actually organization of information,” says Aristotelis. “Regardless of whether you’re designing phones or spaces or products, it’s giving you the right information at the right time and not overwhelming you with information that you don’t need.”
That’s particularly true as AI and onboard software becomes an increasingly large part of space missions. More and more of the functions of controlling a spacecraft like Orion’s altitude and speed are being taken on by the software, putting the astronauts in largely a supervisory role.
“The software is the primary flyer of the spacecraft,” Artemis II pilot Victor Glover said in a video about Orion, comparing the experience of flying the spacecraft to his background in aircraft piloting. “In an aircraft the software is really helping the pilot, and I think now it’s almost like we are helping the software.”
There’s a clear principle that remains in place, though, that software may be taking on more tasks, but humans should always be able to take control if and when needed. One of the reasons that astronauts are selected is their ability to think calmly and creatively in demanding situations. They must be able to make split-second decisions that software cannot.
Software can be an assistant, “but the crew should be able to override,” Bannova says. “They have to have a way of making a decision that might be unconventional, but still might be the right decision — for example in emergency situations.”
“One thing that I’ve learnt from astronauts is that they want to be able to control their own environment,” Aristotelis says, particularly pointing to temperature and climate control as something that astronauts like to have individual control over.
Of course, not every system on a spacecraft can be tweaked by the users. Some essential systems need to operate in a fixed way: “Architecture is subjective, but certain parts have to be designed in the most efficient, optimized, easy-to-repair and -maintain way. And those systems — life support systems, atmospheric generation systems, water recycling — must be designed as close to perfect as possible,” Bannova says.
However, you can contrast these essential systems with more personal spaces like crew quarters, where astronauts can make their own choices about lighting, temperature, and decoration. For engineers and architects working on space environments, that means working with psychologists and sociologists, Bannova says: “That is what will make them think of that spacecraft or that space habitat as home.”
This freedom of choice applies even to the tasks that astronauts will perform as well. On a mission like Orion, there is a fairly fixed schedule for what jobs need to be done at what time. But on longer missions like those to the ISS, crew members are given a degree of scheduling freedom. There might be a list of tasks that need to be completed, but the crew can choose in what order they want to approach them — and this sense of autonomy is vital for human well-being more generally.
The whole design of a spacecraft, including everything from its user interfaces to its exterior, contributes to the sense of safety, community, pride, and purpose that astronauts carry with them into their work. “It’s not only for public relations and pretty pictures,” Bannova says. “It’s also for people living in it and using it, and finding the beauty in it.”