universe has evolved to create a species that can partially understand it: humans.
From the beginning of chaos to the space era, as the only known intelligent life, humans have used various tools to understand the world and transform it, achieving the continuation of species and the evolution of civilization.
However, with the rapid development of artificial intelligence technology today, why do we still need to send people to the sky? How do people and machines work together on space missions? As a aerospace activity with human participation, how does manned spaceflight inject and sublimate the value of "people"?
Manned spaceflight is a complex project composed of multiple systems. It is also a system project constructed by humans, machines and the space environment. In addition to reflecting the national will, inspiring the national spirit, promoting scientific and technological progress, and continuing future civilization, this article talks about the role of humans in space from the perspective of space station engineers, as well as the efforts of manned spaceflight to meet the needs of humans in space. System design.
Human beings are precious and cannot be replaced by anything else; putting people first, aerospace starts from the original intention.
Part 1
Irreplaceable Man: The Extraterrestrial Mission of Intelligent Species
"Those who pretend to be horses are not capable of benefiting their feet, but they can travel thousands of miles; those who are falsifying boats are not capable of running water, but they are unable to reach rivers." As early as more than 2,000 years ago, Years ago, our ancestors concluded that tools such as mules, horses, and boats have greatly extended human capabilities.
Since the industrial revolution , the tools that humans can use have further developed into automated equipment, robots, artificial intelligence , etc. (this article uses the word "machine" in a broad sense). The application of machines has not replaced manpower, but has created more positions in many fields of professional division of labor, industrial chains, and third-party services.
Standing at the beginning of the space age, space pioneer von Braun believed that one of the main tasks of people in the space station was to change camera film. Today, film is no longer used for both earth and space observations. However, not only are people not unemployed in space, but they have more, more complex, and more meaningful jobs. Even astronauts careers have been subdivided. Scientists, engineers and more.
Can machines replace people? This fresh and ancient topic actually already has an answer. For hundreds of years, technology has continued to advance from the earth to the outer space, but the work that humans can do exceeds the capabilities of machines of the same era, or there are higher demands based on the capabilities of machines of the era, which can be supplemented by machines. Or it can replace part of human labor while freeing up hands and brains to do more "advanced" things. "Advanced" is relative to the times, but the unique ability of humans to surpass machines has nothing to do with the times. Therefore, manned spaceflight will always be designed with "people" as the starting point.
Astronaut Michael L. Coats removes film from a jammed IMAX camera during the 1984 Space Shuttle STS 41-D mission. (Source: Space.com/NASA)
1. The big difference is that people are on site.
Space teleoperation is already a basic way for humans to carry out aerospace activities, but the participation of people on site can achieve more efficient and direct operation effects and More comprehensive and rich results. These typical work sites include scientific research and technology experiments, space station operations, assembly and construction of space stations and other on-orbit facilities, etc. Their common feature is that people with professional knowledge and skills can make comprehensive judgments based on diverse information on site, make targeted decisions in real time, and implement physical-level operations.
(1) Scientific research and technical experiments
This type of work is exploratory and is carried out iteratively according to the process of "try-evaluate-correct-try again". People on site can obtain comprehensive test information at the first time, make judgments on the current status and form the next work plan, adjust and determine the test status and parameters. Compared with the expert team on the ground who can only rely on limited telemetry data to carry out their work, the payload expert astronauts can use rich status information to make comprehensive judgments and efficient decisions on site.
On-site experts can also directly replace test samples, adjust test pieces or test facility status.These operations must be "visible and tangible" to be carried out - at least, based on the current technical capabilities, it is much more restrictive and difficult for ground personnel to achieve the same effect through remote control. In the
space station, the configuration of high-performance computers and the development of technologies such as on-orbit 3D printing and in-situ material processing will further enhance the ability of on-site personnel to intervene in experiments. Relying on the space-ground link, manned space activities can form a working model that combines on-orbit testing by payload experts with technical support from professional ground centers, giving full play to the strengths of space and earth.
Screenshot of the video from the official website of China Manned Spaceflight on November 21, 2021, where the Shenzhou-13 crew conducted on-orbit scientific experiments. ( Xinhua News Agency )
(2) Operation of the space station
The space station is a huge comprehensive mechanical, electrical, and thermal facility, containing a large number of mechanisms and electromechanical products. Direct operation by humans is not only efficient, but also easy to operate. Judge the operation results. For example, for the switching or motion status of products such as valves and action mechanisms, the ground is usually based on "whether the open/close command is issued" or "whether a certain part of the mechanism triggers the pressure point switch"; restricted by the sensor principle and implementation method, In many cases, it is difficult to directly judge whether the physical movement of the moving parts of the equipment is in place. Human operation can directly determine the operation results in real time from the handle position, valve angle, mechanism shape, etc.
The biggest advantage of having people on site is the ability to handle things quickly. Once "action failure" occurs, it can be quickly determined whether it is an actual physical action failure or a problem with other links such as sensors or information transmission, and it can be dealt with immediately. The physical actions of mechanical products are most suitable for "seeing is believing". This is why unmanned spacecraft are increasingly equipped with cameras, allowing ground personnel to directly judge the status of the solar wing, the expansion of the solar wing, and the movement of the robotic arm from the images.
(3) Assembly and construction of the space station and other on-orbit facilities
We often compare the on-orbit construction of the space station to building blocks and building a house in space. It is essentially a process of continuous addition, splicing or adjustment of infrastructure, involving a large number of complex and delicate mechanical and electrical operations inside and outside the cabin, which is most suitable for people to show their talents on site.
International Space Station The two big moves last year are typical examples of this type of operation. First, the U.S. module completed the installation and upgrade of two new solar arrays through multiple groups of astronauts going out to perform installation, connection, deployment and other work. Second, Russian astronauts connected cables, network cables and installed extravehicular facilities through extravehicular and in-cabin operations, making the newly launched Nauka multifunctional module truly an integral part of the International Space Station. Since the first module of
was launched in 1998, the assembly of the main structural truss of the International Space Station and the expansion of many cabin sections have been completed by astronauts with the assistance of the robotic arm . As of April 28, 2022, the International Space Station has carried out 250 astronaut extravehicular activities to assemble, maintain and upgrade the space station.
On April 28, 2022, Russian astronauts carried out the 250th extravehicular activity of the International Space Station, setting up a new European robotic arm to help launch it. (Source: NASA)
2. Humans are the backup or supplement of machines.
In manned space activities, human-controlled operations are often used as backup or supplementary means for automatic operations. We can understand that human operation and automatic operation are two independent sets of heterogeneous controllers with different principles. The cooperation of the two can greatly improve system reliability.
A typical independent backup design is rendezvous and docking. In most of the rendezvous process, the system needs to determine the orbit and calculate the orbit, which is beyond the capabilities of humans. At the end of the rendezvous, the active aircraft needs to control its position and attitude with six degrees of freedom, and human vision and movement abilities can come into play during this critical period.At this stage, the automatic system uses radar or optical measurement equipment to measure position and speed, uses an optical sensor combined with a three-dimensional target to determine the relative attitude, uses a control computer to calculate the control parameters and issues control instructions to the propulsion system; the astronauts Observe the target image with direct vision or a camera, rely on human stereoscopic vision to determine the posture, operate the handle based on your own sense of spatial motion and posture judgment, and control the flight movements of the spacecraft . Such a design can ensure that human control can take over immediately when the automatic system fails, ensuring safety and continuing the mission.
Human control as a supplementary design is common in robotic arm operations. In the process of robotic arm-assisted extravehicular activities, large-scale transfers are usually path planned and executed by computers, which can effectively avoid obstacles and optimize mechanism movement. When fine-tuning is required at the operating point, the on-site astronauts understand their own needs better and can obtain more comprehensive three-dimensional spatial information through direct observation than relying on camera images. Therefore, at this stage, the method of "listening to the operating astronaut's command" is often used to carry out mechanical operations. Local posture adjustment of the arm. In order to improve efficiency, this kind of command and execution is usually no longer carried out in the space-ground coordination mode. Instead, the astronauts in the cabin operate the instruments and handles in accordance with the commands outside the cabin. The on-site operation of the European Robotic Arm (ERA) is more "on-site", with an operation box specially configured for extravehicular astronauts. Through the handles and buttons on the operating box, astronauts can operate the robotic arm like an excavator at the extravehicular operation site.
China's first manual rendezvous and docking was successful
3. Responding to accidents is a unique human advantage
The on-orbit facility maintenance that astronauts need to perform is mainly the replacement or repair of hardware equipment, that is, those that cannot be achieved through "soft" methods such as data injection and software upgrades. And the machine can perform projects that are very difficult. During more than 20 years of flight on the International Space Station, astronauts have updated the mechanical pump set that has expired, replaced the malfunctioning control torque gyro, and upgraded the nickel hydrogen battery to a lithium battery. Human operations have covered various types of Equipment repair and maintenance work.
The job where astronauts play a greater role is to deal with problems that are not in the design state and require on-site judgment based on specific conditions. Typical examples include the 5 in-orbit repairs and maintenance upgrades of the Hubble Telescope , and the Alpha Magnetic Mass Spectrometry on the International Space Station. Maintenance of thermal control system of Alpha Magnetic Spectrometer/AMS. In order to solve the problem of Hubble telescope lens assembly error, astronauts went to space to install a correction mirror tailor-made for Hubble ; to make room for the installation within the restricted volume, a relatively unimportant piece of equipment had to be dismantled ( high speed photometer). In the second case, the project developed more than 20 kinds of special tools, which were operated on the ground after ground testing. Follow-up mission plans were formulated based on the actual operation of the astronauts each time they left the spacecraft, and the maintenance of the AMS refrigeration system pipeline was finally completed. .
Emergency rescue is the most severe failure that astronauts deal with, and it is not uncommon in the history of global manned spaceflight. There was a leak in the sealed cabin of the International Space Station. The astronauts located the leak point by closing the door to isolate the cabin section and covering the suspected leak area with plastic film; The air composition was restored and some equipment repaired; the out-of-control Salyut 7 space station was manually docked and repaired by Soyuz T-13 astronauts. Thanks to the astronauts' on-orbit maintenance, the Mir space station, which has a designed life of 5 years, has continued to work for 15 years. The International Space Station can still technically extend its life after more than 20 years of operation.
's "adaptive" on-site handling and emergency rescue are all "unexpected". Once such an abnormal situation occurs, it will be difficult for the machine to respond with optimal performance because the input data is too different from the training data. People rely on their own knowledge, experience and logic to make judgments, and can often solve problems and resolve crises intelligently.
In February 1997, American astronauts went out to repair the Hubble Telescope during the space shuttle STS-82 mission (Source: NASA/ESA)
4. Researchers themselves are also important in aerospace tasks.
Humans are the main body of manned spaceflight activities and are also One of the research objects.From one day on Shenzhou 5 to the six-month stay on the space station mission, Chinese astronauts have been flying continuously in orbit for longer and longer periods of time; research on people in the space environment is not only the basis for ensuring the health and safety of current missions, It is also a prelude to future manned moon landings and interstellar voyages.
Through comparative studies on the physiological and psychological indicators of identical twin astronauts who stayed in space and on the earth for one year respectively, NASA science team partially revealed the impact of space flight on human chromosome telomeres, cognitive ability, and genes. impact on expression. Our country has also conducted in-depth research on the occurrence mechanism of aerospace medical problems based on previous manned missions, and developed high-efficiency comprehensive intervention and protection measures. Aerospace medical experiments, space scientific research and applications, and aerospace technology experiments constitute the three major application areas of China's space station.
Shenzhou 12 Astronaut Nie Haisheng Testing cardiopulmonary function in orbit (Source: CCTV)
Although brain science research has made significant progress, our understanding of the working mechanism of the human brain is still very limited. The complex information processing ability and comprehensive judgment ability are simply like a special gift from the world to the human species.
Allowing machines to perform tasks with a large amount of calculations and relatively certain logic, and allowing people to engage in advanced, creative, and even unpredictable activities, has not only become a consensus in the field of science and technology and production on the earth, but also is a requirement for countries around the world to develop manned spaceflight. The foundation of system design for people to move from near earth to deep space.
Part 2
A foolproof system: the best platform for people in space
Since the role of people in space is irreplaceable, the fundamental responsibility of manned spaceflight is to create a platform for people to work and live in space. Although this platform is most directly embodied in the manned spacecraft , its dimensions actually far exceed the spacecraft itself. It is through the optimized combination of human factors design and technical solutions of various engineering elements, so that the entire system can achieve " People” service at its best.
As aerospace engineers, we need to ensure human safety through the design of spacecraft and its operating systems, establish comfortable living conditions for people based on the basic living environment, and finally design and build efficient workplaces and security condition. All this is not only a response to the needs of manned space missions, but also reflects the late-mover advantage of China's space station design.
1. Safety-first system design
Ensuring the safety of people in space is the top priority of manned spaceflight. Manned spaceflight is a multi-system, multi-professional system engineering project. Focusing on the requirements of ensuring human safety, multiple safety measures have been designed for the configuration and operation of the entire large system.
(1) Safety logic of multi-module space stations
A major advantage of multi-module space stations is that each module is relatively independent and can undertake safety and security functions in a distributed manner, and can ensure global security through physical isolation when local problems occur. .
For example, in the function allocation of the International Space Station module, safety-related functions are backed up and redundant with each other. Despite the high technical difficulties and the inconsistent technical routes between the two countries, the Russian and American cabins still ensure that each section is equipped with a regenerative life support system.
The Chinese Space Station uses the Tianhe core module as the platform control and management center to conduct unified control of the entire station. The Wentian experimental module backs up key functions such as complete energy management, information systems, control systems and manned environment, and can take over overall station control when the core module fails. In response to major failures such as core module fires and loss of pressure, it is also equipped with a complete set of regenerative life support systems and emergency supplies to prepare astronauts for long periods of time waiting for ground fault handling and rescue. The Mengtian experimental cabin has device-level backup of key functions to further improve system security. For the safety of astronauts' extravehicular activities, the Wentian experimental module is equipped with a main airlock module, and the Tianhe core module node module serves as a backup airlock module. If there is a problem with the main airlock module during the exit process, the astronauts can return to the cabin through the node module to ensure the safety and reliability of the exit activity.
The assembly process of the Chinese Space Station in orbit (Source: China Manned Space Engineering Office )
(2) Lifeboats and the ultimate safety solution
Once astronauts encounter safety problems, the ultimate solution is to return to the ground. The ground environment avoids all unsafe factors in space, and the protection that people can get on the ground is almost infinite compared to that in orbit. This "safest" principle puts forward the requirement for the space station to allow astronauts to return to the ground at any time, which leads to the concept of "lifeboat" - the manned spacecraft does not evacuate immediately after sending the astronauts to the space station, but Always stay docked and be a lifeboat for those on the station.
How many people are on the site depends on how many people have life-saving capabilities. This is consistent with the requirement for ships to be equipped with lifeboats. In terms of task arrangement, there are also a series of specific requirements and measures to ensure:
- there cannot be a situation where there are people on the station but no lifeboat, or there are more people on the station than the capacity of the lifeboat, neither temporarily nor long-term. For example, if a rendezvous test is required, or the spacecraft temporarily separates and re-docking to change the docking port, no matter how many people are needed for the operation, all the corresponding crew members must enter the spacecraft to ensure that everyone can be on board if there is a problem with the mission. They are all on the spacecraft and can return to the ground safely.
——The lifeboat cannot completely cut off power during docking, but is in a dormant state. The measurement and control equipment remains on and on duty, and can receive instructions to wake up the entire ship at any time.
- Necessary return materials are stored in the lifeboat, and it is powered on and inspected regularly. The astronauts also have to enter the spacecraft regularly for inspection to ensure that the spacecraft is in good condition and available at any time.
——If the lifeboat fails and cannot return, a new spacecraft must be launched as soon as possible and to the best of its ability to take over.
On October 16, 2021, the Shenzhou 13 spacecraft successfully docked at the radial port of the Tianhe core module. (Picture source: China Academy of Space Technology )
(3) Before going to space, it called the ground rescue ship
to take over the spacecraft of the malfunctioning lifeboat immediately, that is, the ground rescue ship. The long-term manned operation of the space station requires that there must be a rescue spacecraft on the ground that is continuously on standby to truly ensure the safety of personnel in orbit at all times.
Starting from the Shenzhou 12 mission, our country has carried out ground rescue duty in a rolling manner in conjunction with continuous missions. When Shenzhou 12 was preparing to launch, Shenzhou 13 also entered the launch site and completed the test; after Shenzhou 12 was launched, Shenzhou 13 was on standby as a rescue ship at the launch site, and could launch in the shortest time after receiving the rescue order. And perform rescue; before the official mission of Shenzhou 13 begins, Shenzhou 14 enters the launch site and completes the test... In this cycle, each ship performs rescue standby and normal flight missions on a rolling basis. The advantage of this mission mode is that the waiting time on the ground for each spacecraft is short and similar, avoiding a series of problems caused by long-term storage of dedicated rescue ships.
On September 17, 2021, as Shenzhou 12 returned to Earth, Shenzhou 13 changed from a rescue spacecraft to a formal mission spacecraft. (Photo by Xinhua News Agency reporter Ju Zhenhua)
(4) Orbital design aims at safe return
Returning to Earth is the safest, so the orbital design of the space station should also create the best conditions for returning to Earth as soon as possible under various circumstances.
- using the regression track. Manned space stations in various countries are located in orbits at an altitude of 340-450km. This is not only the result of a balanced consideration of the protective effect of the atmosphere on cosmic radiation and orbital attenuation factors, but also because orbits at this altitude have a return characteristic of 2-3 days. In other words, the ground area that the space station passes through (including the return landing area and the ground measurement and control station) repeats in a 2-3 day cycle, and a relatively fixed return flight procedure can be developed. This is very beneficial for ensuring return safety, especially for emergency returns where the time of occurrence is uncertain.
- Design selection return drop zone. When returning normally, the spacecraft should land in an area with better geographical, climate, search and rescue conditions.Our country adopts a land return and landing plan, which has greater design constraints than the splashdown plan at sea, because the landing area that meets the conditions of the landing site is limited and the geographical location is fixed. This requires designing the orbital inclination angle so that the space station can land as much as possible during the return period. Pass the landing zone. If you pass it once a day, you can return to the scheduled landing area according to normal procedures every day. In order to cope with the uncertainty of ground meteorological conditions, it is also necessary to consider setting up a secondary landing area far enough away from the main landing area and where the weather is different. When the space station operates stably and can provide sufficient safety and material support, it can avoid bad weather on the ground and reduce dependence on secondary landing sites by waiting in orbit. In other words, time (waiting for weather) is exchanged for space (choosing another area to land).
- Design selection emergency landing zone. The emergency landing area is set up in case the spacecraft malfunctions when flying alone without the support of the space station and needs to land as soon as possible to ensure the safety of the astronauts. The "as soon as possible" here means that the spacecraft must land safely before its own energy, oxygen and other resources are consumed. Considering the worst case scenario, the failure may occur at any time. The project must combine the orbit return characteristics and select enough and suitable areas around the world as emergency landing areas to ensure that the spacecraft can selectively land in these areas as soon as possible. within the area without falling outside the designed area.
Flight trajectory of Tiangong-1 Space Laboratory (Source: Phillyvoice)
(5) Safety strategy for manned lunar exploration
For manned spaceflight in low-Earth orbit, the spacecraft can return to the ground in about 45 hours in case of emergency; even if Be sure to return to the main landing site, no more than 1 day. Therefore, "returning to the ground" has become a countermeasure for many emergency modes in near-Earth missions. In the Mir fire incident mentioned above, we considered immediately abandoning the space station and returning. In the end, because the fire was under control, we decided to return three people first, leaving three people to continue repair work on the station.
But the moon mission is different. Even if we do not consider the work of taking off from the lunar surface and changing the orbit around the moon, it will take more than 3 days just to return from the lunar orbit back to the earth orbit, which is too long in terms of emergency situations. When the author communicated with his Russian colleagues, the other party attached great importance to the fact that if manned lunar exploration is to continue on the lunar surface, the emergency strategy for low-Earth orbit must be changed and a new emergency system must be formed.
In fact, in the long-term lunar exploration mission plans currently proposed by various countries, lunar orbiting space stations have been designed. An important role of the lunar orbit station is to serve as a temporary safe shelter for lunar personnel in emergency situations. Compared with the unknown environment of the lunar surface and the cost of propellant required for landing on the moon, a space station that is safer, more reliable and has more sufficient resources can be built and operated in a stable lunar orbit. From a security perspective, such a configuration plan actually forms a security system of "forward exploration (lunar surface activities) - forward base (lunar orbital space station) - rear area (earth)".
2. Spacecraft as a place for space survival
On the premise that safety is guaranteed, spacecraft must provide basic living conditions for people.
(1) Atmospheric environment
During orbital flight, people spend most of their time in a sealed cabin, which consumes oxygen and produces carbon dioxide and some harmful gases. At the same time, the equipment and test devices on the space station will also release a small amount of harmful gases. Therefore, the cabin environment requires dynamic control of atmospheric pressure and composition. Since the Mir Space Station, long-term space stations have carried regenerative life support systems; the Chinese Space Station is also equipped with systems such as electrolytic oxygen production, regenerative carbon dioxide removal, trace harmful gas purification, condensate water treatment, and urine treatment to achieve high-material Closed-loop manned environment control.
(2) Microbial control
Microorganisms will breed in the environment where people live. If left unchecked, microorganisms not only harm human health but also corrode equipment. Therefore, microbial prevention and control is an important issue involving the safety of the living environment for long-term manned flights.
The microbial control of the space station is also a systematic project.From the selection of antibacterial and anti-mildew materials, cleaning, inspection and environmental control during equipment production and cabin assembly testing, to purification through air purification, water purification and surface wiping after flight, only continuous control of microorganisms can ensure a healthy living environment for people. .
(3) Space environment protection
Cosmic rays harm human health. Atmospheric protection, aircraft protection and flight time control are three ways of human body protection. In terms of protection equivalent, the earth makes the greatest contribution. Protection of the earth's atmosphere and magnetic field in the low-Earth orbit area can reduce the intensity of galaxy cosmic ray radiation by 70%-90%; the aircraft adopts a metal structure, and the equipment is reasonably laid out in human activities The perimeter of the zone is an effective means of protection; at present, astronauts from various countries usually do not fly for more than half a year each time, in order to control the total radiation dose.
In the following situations, if the above three methods are not met at the same time, there will be a risk of impact on the space environment:
- Extravehicular activities. The astronauts lose the protection of the spacecraft's metal shell during EVA activities, and the radiation dose accumulated during the EVA period must be calculated separately. In addition, when countries plan normal extravehicular missions, they usually ask astronauts to avoid the South Atlantic anomaly during the 6 to 8 hours of extravehicular flight - the magnetic field intensity in this area is 30-50% weaker than the surrounding area, The Van Allen radiation belt is depressed here to 200km, and a space station flying in a 400km orbit will receive stronger radiation when it passes through it.
- Flexible inflatable cabin. Bigelow Aerospace's Bigelow Expandable Activity Module (BEAM) has been docked and put into experimental application on the International Space Station, and many other companies' commercial space stations have also adopted flexible cabin solutions. Flexible cabins constructed with multiple layers of new materials have greatly improved performance in terms of thermal insulation, space debris protection, structural strength, sealing, and internal anti-scratch and puncture resistance. However, due to the low density of the material, the protection effect against space radiation is limited. Still much lower than metal. Therefore, BEAM is currently just a test chamber with a normal atmospheric environment. Personnel can enter but cannot stay for a long time. The on-orbit performance of the flexible inflatable capsule is still being evaluated.
- deep space flight. Manned deep space flights often take months or even years and are far away from the earth. The current level of spacecraft technology cannot guarantee the safety of radiation doses for crew members, and all three protection measures are insufficient. The same problem exists when working in an atmosphere-free environment such as the moon for a long time. Therefore, radiation protection measures for deep space vehicles and the use of in-situ resources on the lunar surface to build protective sites are worthy of in-depth study.
Space station regenerative life support system architecture (Source: Aerospace Medicine and Medical Engineering )
3. Life in space can be better
After the survival problem is solved, it is necessary to improve the living conditions for astronauts so that they can fly longer and work better . With the accumulation of practical experience in manned spaceflight and the advancement of technology, the living conditions of the space station have gradually evolved from ensuring adequate hardware conditions to taking into account both physical and mental health.
The dome module (Cupola) on the International Space Station is an excellent design. It is a panoramic attic that protrudes 1.5 meters from the surface of the cabin. It provides an observation point for flight engineers during tasks such as robotic arm operation and docking of visiting aircraft. It has a more meaningful role in allowing astronauts who have lived in small and confined spaces for a long time to come here. Look at the earth and starry sky everywhere, adjust and relax your mood. The dome cabin should be the result of the dual effects of design concepts and technological progress. In the past, it was difficult to imagine that anyone would specially develop a panoramic skylight with a diameter of nearly 3 meters and a weight of 1.8 tons. It seemed to have no substantive engineering functions and send it to the sky.
The dome module on the International Space Station (Source: NASA)
In terms of living conditions, the Chinese Space Station has introduced livable design concepts to provide astronauts with convenient living and psychological and physiological health protection:
- living area and work area. The two areas are relatively independent, and the space size, lighting, color, logo, etc. have been specially designed. The living area is equipped with bedrooms, kitchens and bathrooms, and convenience and privacy are fully considered in the layout and equipment configuration. As a design requirement, each bedroom has portholes, and the living and working areas have corresponding noise indicators and control measures.
– Exercise facilities. The cabin is equipped with fixed exercise facilities such as treadmills and bicycles. The astronauts are also equipped with portable exercise equipment and resistance exercise devices such as tensioners . Scientific on-orbit exercise helps astronauts maintain their physical fitness and physical functions, which is beneficial to both completing on-orbit missions and returning to the ground for recovery.
- smart home management and entertainment. Based on the wireless WiFi network, the project designed work, life, and entertainment APPs for astronauts to realize smart home management and material management of the space station through smartphones and tablets.
- Tiandi Network. The space network ensures two-way audio and video. Astronauts can not only watch TV programs on the ground, but also use Internet calls to talk to family members, teammates, doctors, and technical support personnel. This is truly "the world is as close as our neighbor".
Shenzhou 12 astronauts exercise in orbit (Source: China Academy of Space Technology)
4. Going to heaven is for work
Going to heaven is to perform tasks. On the premise of being safe and livable, manned spaceflight must design better workplaces and convenient working methods for astronauts.
(1) human-machine interface design
For the equipment and interactive interfaces operated and used by astronauts, ergonomic design is carried out simultaneously from the planning stage. With the development of the space station, related products must also be verified and evaluated on the ground at all levels from system to standalone to ensure that astronauts can control them safely, efficiently and conveniently after going to space.
(2) Maintenance design
If a worker wants to do his job well, he must first sharpen his tools. Since maintenance is an important part of astronauts' on-orbit work, the space station must carry out a series of designs to meet maintenance needs. Its main tasks include:
- maintenance needs identification. Simply put, equipment that is relatively easy to break and has a short lifespan, or important equipment that affects safety and missions if broken, must be designed to ensure that they are repairable. The former is like batteries and pumps with limited life, and the latter is like life support equipment. On the other hand, if some equipment cannot be repaired or is too costly to repair, it must be designed and manufactured to be reliable enough, such as piping systems and trunk cable networks. This is similar to renovating a house: faucets and light bulbs are replaceable, but the upper and lower water pipes and power supply lines buried in the wall usually cannot be repaired or replaced and are not easy to break.
- The device is repairable. For a single piece of equipment, it is necessary to ensure that astronauts can see clearly and operate it reliably in a weightless environment or even wearing extravehicular suits, and that the repair effect can be effectively tested. Special tools can be designed if necessary. The maintenance of extravehicular equipment is more difficult. In order to allow astronauts to carry out corresponding operations while wearing extravehicular gloves, operating handles, cable plugs, etc. are specially designed. When making equipment installation layout, consider that astronauts have sufficient operating space and lighting conditions.
- System support for serviceability. On-orbit maintenance cannot shut down the entire station like it can on the ground. During maintenance, the faulty equipment must be isolated and the system must be kept running. Just like when changing a faucet, the upstream water valve must be turned off, and when changing a light bulb, the switch in this room must be opened, while other rooms can still use water and electricity normally. The design on the spacecraft includes: repairable equipment can have alternative equipment to continue to work and maintain functions, or it can be powered off for a short time without affecting system operation; the power supply system can be partially powered off to repair or replace faulty equipment, and the rest can maintain power supply. The equipment can maintain system operation; the information system must allow the equipment to be removed and connected without causing problems such as network protocol conflicts.
- Tool design. Astronauts' hand tools, robotic arms and even robots are all tools that need to be designed. From the four extravehicular missions that the Chinese Space Station has completed, we can see typical extravehicular operation tools and their performance. The astronaut crew performs efficient human-machine collaboration and controls the robotic arm to complete the transfer of people and equipment; the extravehicular astronauts use fully functional tools to complete maintenance or assembly tasks; the astronauts wearing extravehicular suits are arranged on the outer wall of the space station. The foot limiters used to fix the body ensure that the astronauts can use their hands and feet at the operating point.
Chinese Space Station robotic arm during ground testing (Source: China Academy of Space Technology)
(3) "Spaceport" design
The entire space station is a "easy" workbench and "handy" tool for astronauts. It also It can become a space home port for visiting spacecraft and provide them with service guarantees. For example, based on the innovative on-orbit service model of co-orbital spacecraft, the survey space telescope can dock at the Tiangong Space Station for a short period of time for propellant replenishment and equipment maintenance and upgrades.
Compared with the huge cost when the United States had to launch space shuttles multiple times to repair the Hubble Telescope, the common-orbit flight service model is convenient and economical, and has greatly expanded the "one specialty, multiple capabilities" of manned spacecraft. This working mode also gives full play to the strengths of unmanned and manned aircraft and avoids conflicts that may arise from different working states. When the survey telescope is working normally, it is an unmanned satellite. There is no interference from human activities, and it can obtain high-precision and high-stability attitude control, which is extremely beneficial to astronomical observations. When it needs repair and maintenance, it will be docked on the space station and become the backbone of the manned spacecraft. In part, astronauts can perform related operations.
(4) The cooperation between heaven and earth guarantees
Astronauts do not fight alone in the sky. Efficient coordination between heaven and earth is an important guarantee for giving full play to the strengths of heaven and earth.
The return of Apollo 13 is a classic case: the spacecraft was close to the moon, the service module oxygen tank exploded, and the ground control center made a decisive decision to cancel the moon landing mission; the astronauts implemented emergency power supply and air purifier modifications with the support of the ground engineer team and return braking, and finally successfully returned to Earth. The BEAM inflatable capsule mentioned earlier provides a contemporary example of space-earth collaboration: During the first deployment of BEAM, the deployment was aborted because the friction between the soft fabrics of the inflatable capsule exceeded expectations. The three teams of space and earth - the spaceflight in orbit The crew, the NASA team at the flight control center, and the Bigelow development team—coordinated to locate and handle the fault. Ground engineers observed changes in the status of the cabin all night long. Combined with the astronauts' on-site inspection, several parties discussed to locate the problem and guided the astronauts' operations in real time, forming a "astronaut operation - changes in the inflatable cabin - collaborative observation and judgment between space and ground - discussion and formation." A closed loop of "opinions on next steps". During the more than 7 hours of the second deployment, the astronauts manually opened the inflation valve 25 times to successfully fill and deploy BEAM.
The core module of the China Space Station has been flying in orbit for more than a year. Judging from the completed missions outside and inside the cabin, the on-orbit operation mode supported by the space and earth system has taken shape. In the future construction, expansion, upgrade and on-orbit service applications of the space station, astronauts' on-orbit operation capabilities supported by professional ground teams will be more powerful and will more fully play the role of humans in space.
The scene of Shenzhou 13 astronaut Zhai Zhigang exiting the cabin, taken at the Beijing Aerospace Flight Control Center on November 7, 2021 (Photo by Xinhua News Agency reporter Guo Zhongzheng)
Over the past thousands of years, technology has changed the main form of human labor, which has further highlighted the of human intelligence. The update of technology and the progress of people are moving forward in dynamic complementation and adaptation to each other. People use their wisdom to continuously create more advanced technologies, and people must improve themselves to adapt to the speed of technological iterations; technology extends people's capabilities, expands people's living space, and provides better conditions for realizing people's all-round development.
This is what it means to be in space.
The era of China’s space station is slowly beginning. People have made the space station, and the space station will also make and enhance people's value and dignity; people are part of manned spaceflight, and together with manned spaceflight, they form a larger system, where they can jointly explore the margins and question the world. (End)
Producer: Li Xiaoyun
Editor: Wang Xinrong
Proofreading: Cui Yicong
