Touch screens are unpopular? The buttons on manned spacecraft have their own rules

With the successful entry of the Tianhe core module into orbit, China's manned space flight has fully entered the space station era. Two crews of three astronauts each boarded the Shenzhou XII and XIII spacecrafts to enter space and stationed at the Tiangong.

From the video of the connection between heaven and earth, we can get a glimpse of the internal layout of the spacecraft, and some careful netizens have noticed many buttons inside the spacecraft and the space station. These buttons have complex functions and have been carefully designed by designers to help astronauts better control the spacecraft in space.

Astronauts operate buttons while reading the operating instructions

# Dazzling control area#

Before the 1970s, as computer technology was not yet mature enough, scientific researchers used assembly language to develop spacecraft operating instructions. Manned spacecraft displayed status and operating procedures through displays and were equipped with a large number of joysticks, buttons, alarm lights, instruments, etc.

At that time, most manned spacecrafts of the United States and the Soviet Union used electromechanical instruments, and the layout of the cockpit was inspired by the "T"-shaped layout of aircraft cockpits of the same period. According to the navigation mission of the manned spacecraft, the most important instruments for astronauts to operate, such as the full attitude indicator, horizon, flight altitude and other basic instruments, were placed in the main viewing area of ​​the astronauts to complete the main task. In addition, some minor flight instruments were arranged near the main viewing area.

Photographer Dan Winters once took a photo collection titled "Space Capsule", which shows the cockpits of three space shuttles: "Endeavour", "Atlantis" and "Discovery". Buttons of different shapes and functions are arranged near the cockpit control panel, installed on the four walls of the cockpit and even on the "ceiling".

On January 16, 2015, NASA released a video of the internal structure of the International Space Station. In order to meet the needs of astronauts' lives, space station maintenance, scientific research, etc., the functions of the space station buttons are more diverse.

NASA releases photos of the interior of the International Space Station

These buttons include buttons to ensure the normal operation of the spacecraft, mainly buttons to control the attitude control system, life support system, radio communication system, etc.; there are also buttons to ensure the work and life of astronauts, such as buttons to control the air renewal system, wastewater treatment and regeneration system, and space services. Their functions include controlling the flight attitude of the spacecraft, monitoring the working status of the spacecraft, and protecting the lives of astronauts. However, in many cases, these systems are automatically controlled by computers, and only in emergencies or when there are special needs will astronauts manually operate those buttons.

# Unwelcome touch screen#

With so many buttons on manned spacecraft, scientific and reasonable design is particularly important. It is necessary to ensure ease of operation while avoiding various designs that are prone to problems.

For example, when a manned spacecraft is operating in space, due to the complex space environment, astronauts may often be in an upside-down position to operate buttons, making it difficult to input complex commands. Therefore, when defining buttons, it is necessary to try to avoid having astronauts input commands frequently or input commands that are too long.

Touch screens should be avoided as much as possible in manned spacecraft. Touch screens are easy to operate and bring great convenience to people's lives, but they are rarely seen in manned spacecraft. Why is that?

First, from the perspective of operability, touch screens are more prone to "misoperation". Unlike physical buttons that require "pressing", the virtual buttons on touch screens are "just tapping". Spacecraft will shake violently during flight, and it is very difficult to "hit the target with one shot", so it is difficult for astronauts to control the spacecraft on the touch screen at this time.

Secondly, from the perspective of reliability, touch screens are more likely to have problems or be damaged than physical buttons, and once a problem occurs, the control keys on the entire screen will be unusable. If the touch screen becomes the only operating medium for the main control system, once a problem occurs, astronauts will lose control of the spacecraft.

On the contrary, physical buttons have been recognized as the most reliable design and have accompanied the development of manned spacecraft. It gives people physical feedback during operation and is more realistic and accurate than touch screens.

Orion spacecraft control interface

# Five Principles of Button Design#

Spacecraft are not programmers' computers that just need to input commands and wait for output results. In daily flight, astronauts need to manually operate buttons to complete specific tasks, such as extravehicular maintenance, scientific experiments, and human health testing. There are five main principles for designers to design products based on user needs:

First, the button design must be absolutely simple. Complex functions should be integrated into one button, and one control button should complete one function. Moreover, the buttons are independent of each other, so the damage of one button will not affect the normal operation of other buttons.

For example, the docking and separation actions of the cabin are controlled by independent buttons, including buttons for docking and separation controlled according to program settings, as well as buttons for manual docking and separation.

Second, it is necessary to provide operating instructions. Spacecraft designers have compiled operating instructions, but they still need to spend a lot of time to memorize these operations before they can perfectly complete the demonstration and verification test. Astronauts are not spacecraft designers. Although they have also undergone long-term training, they cannot rely entirely on their memory of operating instructions in a high-pressure environment. Instead, they must be equipped with operating instructions in case of emergency.

The "Shenzhou XII" astronauts held the operating instructions in their hands while performing operations, which were specially provided by the designers for users.

Third, the buttons should be arranged according to their importance and different colored button lights should be set. These designs can help astronauts intuitively understand the importance of the button functions, shorten the search time, facilitate operation, and reduce the probability of making mistakes.

The buttons of the US space shuttle follow the above principles. These buttons of different colors are arranged neatly and regularly on the control panel, making them clear at a glance.

Fourth, important indicators and alarms are clear at a glance. When a manned spacecraft has a problem, in addition to the alarm, a warning light will also flash, and the warning light will also be set to different colors to distinguish the importance of the alarm.

Red marks the highest alarm, and the most difficult problems must be placed in the most obvious position, such as when there is insufficient oxygen.

Fifth, there must be a design to prevent accidental operation. Important control buttons should be equipped with protective covers to prevent accidental touches, such as the return button. Imagine that an astronaut accidentally pressed the return button during a mission...

In addition, software and hardware are used in manned spacecraft to coordinate the operation process. For example, the attitude control of the spacecraft is completed by three parts: the measuring device, the data processing system and the actuator.

# Future Development Trends#

Human-computer interaction adheres to the human-centered design concept. After years of development, the level of voice control technology has rapidly improved. With the support of voice recognition technology, computers can understand human language instructions to complete control. This technology can be used to realize the flight automation of manned spacecraft. The expansion of this function can not only reduce the physical load of astronauts' operations, but also shorten the astronauts' reaction time.

On May 31, 2020, the manned Dragon spacecraft developed by SpaceX successfully completed its first flight. During the launch, in addition to the launch vehicle, many people also noticed the operating system of the manned Dragon spacecraft. Its control interface does not have many buttons and dials, but uses a super large touch screen, which looks like the touch screen on the Tesla electric car. There are many complex systems integrated on the screen, and the entire operating system looks very cool and amazing. Due to the few physical buttons, the entire cockpit looks very simple and full of technology.

Extra-large touch screen of manned Dragon spacecraft

For emergency use on the manned Dragon spacecraft

Physical buttons

With the continuous development of aerospace technology, a series of changes are taking place step by step, and the number of physical buttons on manned spacecraft is gradually decreasing.

With the improvement of touch screen reliability and the development of voice assistant technology, perhaps in the near future, manned spacecraft will be very easy to use and more in line with our imagination of what a spacecraft should look like.

Source/China Aerospace News WeChat Official Account Text/Ma Zhenzheng

Editor/Yang Sishuang

Review/Yang Jie

Producer/Cao Xiaoyong