Science Research and Utilization Planning of China’s Space Station in Operation Period 2022–2032

GU Yidong GAO Ming ZHAO Guangheng

Science Research and Utilization Planning of China’s Space Station in Operation Period 2022–2032

GU Yidong GAO Ming ZHAO Guangheng

(100094)

The core module of China’s Space Station (CSS) is scheduled to be launched around the end of 2020, and the experimental module I and II will be launched in the next two years. After on-orbit constructions, CSS will be transferred into an operation period over 10 years (2022–2032 and beyond) to continuously implement space science missions. At present, based on the project selection and research work in the ground development period of CSS, China is systematically making a utilization mission planning for the operation period, which focuses on the fields of aerospace medicine and human research, space life science and biotechnology, microgravity fluid physics, combustion science, materials science, fundamental physics, space astronomy and astrophysics, Earth science, space physics and space envir-onment, space application technology,. In combination with the latest development trend of space sci-ence and technology, China will continue to update planning for science research and technology develo-pment, carry out project cultivation, payload R&D, and upgrade onboard and ground experiment suppor-ting systems to achieve greater comprehensive benefits in science, technology, economy, and society.

China’s space station, Utilization, Planning, Experiment

1 Progress of CSS Development

The core module of China’s Space Station (CSS) will be launched by the launcher Long March 5B after 2020, the experimental module I, II will be launched in the next two years and the assembly of three modules is expected to be completed around 2022, and then the CSS will be transferred into an opera-tion period over 10 years (2022–2032 and bey-ond)[1]. At present, the scientific experimental racks and related supporting systems are in the pressurized module and some exposed facilities are being developed. By 2019, China has issued two large-scale AO (Anno-uncement of Opportunity) to solicit scientific research and application projects, published a number of project guidelines[2], a total of nearly 1000 proposals have been received, which laid a good foundation for the ground research and pre-paration for the follow-up consecutive projects of CSS. Based on all these works, China is systema-tically working out a complete scientific research plan on board for CSS operation which will guide to make full use of the experiment facilities and maximize the utilization efficiency.

2 Main Mission of CSS Operation

CSS aims to become a national space labora-toryat an international advanced level in the opera-tion period. The main mission of CSS comprehen-sively focuses on the research fields of space science, aero-space medicine, and new technology for future applications, continuously implement science and other application projects on orbit. At the same time, firstly, it is necessary to continuously update the planning of CSS utilization, carry out project cultivation (ground research), and payloads R&D,make full use of the facilities that have been planned in CSS ground development period. Secondly, it is nece-ssary to further expand the scale of researches and utilizations by making full use of the resources inside and outside three modules, to promote new scientific experimental platforms and facilities. Th-irdly, it is necessary to make rational and effi-cient use of relevant scientific data and research results, sy-stema--tically and comprehensively popul-arize tech-nology and achievements, lead interna-tional cooper-ation and expand space educations, to achieve gre-ater benefits in science, technology, econ-omy, and society ultimately.

3 Planning Ideas

The science planning should be based on the prin-ciple of combining science and technology to ensure every project with high scientific significance and cutting-edge technologies. At the same time, it must pay attention to the maturity of the technical solu-tions of the mission and consider the feasibility of the project, and establish project cultivation mech-anism to carry out ground research in depth, strengthen the integration of science and engineer-ing, and improve the Technology Readiness Level (TRL), so that engineering development could effe-ctively under the guidance of planning. Firstly, expert teams composed of chief scientists, senior scientists (inclu-ding exp-erimental system engineers) and young scientists have been organized to conti-nuously specify a syste-matic, serialized and step-by-step research plan, to optimize the top-level design of key research dire-ctions for CSS. The top-level design will contri-bute to the foundational frame-work and main con-tent of the planning. Secondly, the planning process will con-tinue to collect new research proposals and ideas through an extensive AO mechanism effectively supplement the planning contents. In addition, based on the planning priori-ties, targeted project guidance can be conducted for directional AO, so that the science planning can be closely integrated with the specific research projects, which will help to cons-olidate major projects with scientific significances and influential results.

Before the launch of CSS until the whole op-eration period, the planning is expected to provide a clear and definite reference for scientific research and utilization, continuously guide to review and select high-quality projects, and to propose a scientific project planning suitable for the project implemen-tation through ground cultivations (ground rese-arch funding), so as to maximize the outputs in funda-mental science researches, applied basic rese-arches, and related technological innovations.

4 Science Planning for CSS Oper-ation

China’s manned spaceflight program has accu-mulated utilization experiences and achieved fru-itful research results in Shenzhou spaceships and Tian-gong laboratories. With the ground develop-ment of CSS, planning has been carried out for many years. On those earlier bases, at present, the planning is more oriented to the international sci-entific frontier[3], to original innovations and China’s development needs[4], and all work will comply with a more com-prehensive science plan with series research fields and directions.

4.1 Aerospace Medicine

The field of aerospace medicine focuses on human science and major medical problems that restrict human long-term spaceflight[5]. It also takes into account the health needs of the general public on the ground. The planning is mainly to research and solve the problems of long-term weightlessness on astron-aut’s physiological functions and protec-tion mecha-nisms, impacts of space radiation on astronaut’s health and protection mechanisms, new technologies and methods for aerospace medical research, mech-anisms of traditional medical aero-space application technology, aerospace nutrition, and metabolic mech-anisms,. Research achieve-ments are expected to provide basic support for the long-term mission health in the space station, pro-vide technical support for improving the operation ability of astronauts, and accumulate experience for longer-term manned flight and manned deep space exploration.

4.2 Space Life Science and Biotechnology

Researching the existence, response, and activi-ties of life under space radiation, microgravity and weak magnetic could deeply understand the nature of life phenomena and the needs of human long-term space exploration. The objectives of space life scien-ce research are to promote the understanding and cognition of the essence of life phenomena and to explore the scientific laws, including the perception and response mechanism of various levels of life to the change of gravity[6]; the mechanism of damage, change and stress under space radiation; the basic issues of the controlled ecological support system, and the exploration of the origin of life. Space bio-technology is focused on obtaining innovative mate-rials, drugs, and medical technologies by using space microgravity and other environments. It is expected to help improve people’s health, the dev-elopment and application of regenerative medicine, biological cell therapy, biological medicine, and environmental biotechnology; carry out research on biomolecular design and its synthetic biology, exp-and germplasm resources by using space radiation mutagenesis, and promote agriculture and medicine service: develop the controlled ecosystem that can operate stably and adapt to the needs of long-term human space exploration.

4.3 Microgravity Fluid Physics

The planning of microgravity fluid physics fo-cuses on discovering new phenomena and new laws of fluid movement under microgravity conditions, expanding the development of fluid basic theory, realizing new systems that are difficult to construct on the ground, and forming systematic theoretical innovations and technological breakthroughs[7]. The science research focuses on the dynamics of interface and diffusion processes, including multiphase flow and heat trans-fer problems, and complex fluid behavior. The appli-cation research is closely related to fluid management, chemical smelting, biology and medicine, material manufacturing and process-ing, and is helpful to solve the key technologies of propellant management, optimizing propellant storage and transportation on-orbit. On the ground, it is con-ductive to the transfer of related technologies, and promoting R&D and manufacturing of new high-efficiency-safe space fluid and thermal equip-ment.

4.4 Microgravity Combustion Science

The planning of combustion science focuses on combustion characteristics and basic theory rese-arch, space fire safety,. In addition, microgravity com-bustion science research is closely related to energy saving and emission reduction, improving the chara-cteristics of spacecraft engines, and testing the flam-mability of related materials. The research achie-vements are expected to deepen understanding of droplet-phase, gas-phase, and solid combustion phen-omena in reduced gravity with longer durations, larger scale. CSS will establish the international leading combustion research platform which can provide advanced diagnostic means, integrate mod-els with experiment and design, and provide other knowledge to terrestrial applications.

4.5 Space Material Science

Space materials science is an integrated field with both science and applications. More discoveries, tech-niques, and methods of materials research can be obtained under microgravity conditions. The plan-ning focuses on material science and the natio-nal strategic needs, will carry out serialized and inter-di-sciplinary researches on the basic theoretical issues of material science and the development of new materials with major national needs. The plan is related to: firstly, revealing the special physical and chemical properties and processing rules of various materials under the conditions of space environment, solving key scientific issues in mater-ials micro-structure and defect control, enriching and develop basic theories of materials science, and guiding the research and app-lication of ground materials science; major break-throughs are expe-cted in the basic prin-ciples of material science, materials preparation and processingmethods, and develop-ment of new mate-rials; secondly, researching and preparing new mate-rials is expected to achieve important results in spe-cial structural materials, functional materials, energy materials and biolog-ical materials; thirdly, recogni-zing the special laws and behaviors of materials in the outer space env-ironment, and providing scientific basis for the design and development of advanced materials and com-ponents for aerospace engineering and space technology are expected; fourthly, develo-ping new types of space materials science on-orbit experimen-tal facilities, and making important brea-kthro-ughs in terms of guarantee conditions, experi-mental tech-nology and research capabilities.

4.6 Fundamental Physics

An important advantage of using space condi-tions to research fundamental physics is that high- precision physical measurements can be performed, many of the essential problems of modern physics are likely to be solved only through space research. The planning of fundamental physics in microgr-avity is going to make use of the Cold Atom Exp-erimental Rack (CAER) for carrying out a series of ultra-cold atomic physics experiments under extr-eme conditions to achieve breakthroughs in the theories of modern phy-sics[8]. Utilizing the High-precise Time-Frequency Rack (HTFR) to improve the stability and accuracy for precise fundamental physics research, will pro-mote practical applications, such as leading the quan-tum sensor technology, and promoting the advanced technologies and science for high precision measure-ment in space. As for the complex plasma physics research, a world-leading microgravity complex pla-sma experiment platform will be developed into a series of basic science and applications such as the interaction between dust particles and the spacecraft.

4.7 Space Astronomy and Astrophysics

With the prosperity of international big-science project, the observation of space astronomy entered a new age of multi-messenger with all-weather, all- round, high-resolution, high-sensitivity, and wide- field detection. Space Astronomy and Astrophysics is highly valued in CSS, the 2 m-caliber China Space Station Telescope (CSST, or called Multifunctional Optical Facility)[9], the High Energy Cosmic-Radia-tion Detection (HERD)[10], POLAR-2[11]and other astronomical observation equipment will be laun-ched after 2022, those will acquire a series of major breakthroughs in international frontier hotspots such as dark matter and dark energy, the origin of cosmic rays, the formations and early evolutions of the universe, the large-scale structure of the unive-rse, galaxies and supermassive black holes, and exoplanet search,.,it is demonstrated the ult-raviolet teles-cope will open up a new research field and fill in the blank of the observation of the ultraviolet diffuse source. These studies will make outstanding contri-butions to the development of astronomy, physics, and a series of key technologies such as high-sensi-tivity particle detection, ultra-low temperature refr-igeration, and high-precision pola-rization detection. These technologies will streng-then engineering deve-lopment, including optics, high-performance elec-tronic devices, and advanced electromechanical and thermal technologies.

4.8 Earth Science

Using the CSS platform to conduct Earth sci-ence project could cross-penetrate with other discip-lines and supplement science satellites, with a long term, a more refined, in-depth and more quanti-tative pers-pective to detect and understand the Earth, and can provide possibilities for many basic scientific problems on Earth science and acquire many application achievements that were difficult to solve on the ground. The planning of Earth sci-ence focuses on developing a new generation of high-precision and quantitative remote sensing technology, to acquire multidimensional information of the Earth system, research global climate change and natural disasters, monitor environmental poll-ution, and explore resources.

4.9 Space Physics and Environment

The orbit of the CSS is located in the middle chain of the Sun-Earth system, which is involved with different physical properties, various physical phenomena in unique high-vacuum, high-radiation, and high-condu-ctivity environments. It is an imp-ortant channel for material and energy transfer, such as the mechanism and path of the matter outflow, the energy deposition[12]. The science plan-ning foc-uses on a comprehensive exploration of near-earth space environment, remote sensing of solar physics, and remote sensing of planetary space environment. Making full use of the advantages of long-term stab-ility in orbit, multiple detectors with long-term ob-servation data, explore the role of the plasmasphere in the coupling process of the iono-sphere and the magnetosphere, the influence of the plasmasphere on the near-Earth space envi-ronment, to establish a dynamic three-dimensional model of the plasma-sphere. To understand the origin and burst mech-anism of the solar activity such as the transmission mechanism of matter and energy in the solar atmo-sphere, scientific problems such as coro-nal heating, triggering and acceleration of solar wind, the origin of solar activity will be analyzed in order to improve the forecasting model accuracy of near-earth space weather.

5 Upgrade Planning of Experiment Support Systems

5.1 Onboard Experiment Support Systems

The onboard science experimental systems are mai-nly composed of experimental racks in-station and exposed experiment facilities extra-station. At present, the experimental racks include experiment rack Life and Ecology Research Rack (LER), Biot-echnology Research Rack (BTR), High Microgravity Level Research Rack (HMLR), Fluid Physics Rese-arch Rack (FPR), Cold Atom Physics Research Rack (CAPR), High Precision Time-Frequency Sy-stem (HPTFS), High-Temperature Materials Rese-arch Rack (HTMR), Containerless Materials Proc-essing Rack (CMPR), Two-Phase System Research Rack (TPSR), Combustion Sciences Research Rack (CSR),Glovebox and Cold Storage Rack (GCSR), On-orbit Maintenance and Manipulation Work-bench (MMW), Varying Gravity Research Rack (VGR)[13]. The exp-osed experiment facilities include Biology Research Exposed Facility (BREF), Mat-erial Research Exp-osed Facility (MREF), and Components Test Exposed Facility (CTEF). All the experiment capabilities can provide effective supp-ort for most of the projects planned in the early operation period.

To ensure the continuous and efficient develo-pment of on-orbit science projects, it is necessary to carry out maintenance and capacity improvement of onboard experimental support systems including scientific experimental racks, CSST, payload adap-ters, exposed experiment facilities, information sy-stems, application fluid circuits. The scientific expe-riment racks need to be periodically replaced with components, upgraded in the diagnostic met-hods and scientific experiment modules, replaced by new SDU and SPU,. The fluid circuit needs to be upgraded and improved in heat dissipation capacity. The level of microgravity environment needs to be improved by developing the active vibration isola-tion devices and microgravity measurement network. The on-orbit storage and transportation equipment needs to be developed to meet the storage require-ments such as active biological samples and special test samples. The CSST needs to reserve key com-ponents, coope-rate with astronauts and space sta-tion systems to conduct maintenance training, prepare maintenance manuals, and update back-end scientific modules.

5.2 Ground Experiment Support Systems

The ground experimental support system mai-nly consists of the mission development support system, Payloads Operation Management Center, and ground research infrastructures. During the operational period, Firstly, it is needed to ensure the routine operation and maintenance of the fac-ility building in CSS ground development period. Secondly, it is needed to build a full-lifecycle coll-aborative design system, demonstration support system, project certification test system,., for the large-scale and complex characteristics of a science project during the operation period. The upgrading of the ground experiment support system will strengthen the ope-rational support for planning, demonstration, deve-lopment, and management of space science project, and will improve the capab-ility of integrated test for experimental payloads, and will improve the support capability and intellig-ence level of the payload operation management system.

The ground experiment base of space labora-tory aims to build the world's leading ground exp-eri-mental base, including experimental research, sample analysis, simulated microgravity experi-ments, and data processing. In the meantime, the ground mirror platforms of the experiment system are being developed and built, which could solve the problem of the shortage of ground station scientific research facilities and provide support for the continuous research work before launching.

6 International Cooperation, Education and Achievements Transfer

International cooperation in a variety of ways can be carried out during the CSS operation, in-cluding sci-entific experiment, project cooperation, astronaut training, and visits,. In 2018, China Manned Space Agency and the United Nations Office for Outer Space Affairs jointly issued a coo-peration opportunity announcement to the United Nations members, inviting member states to parti-cipate in space science and utilizations in the China Space Station. 42 project proposals from 27 coun-tries were received. Through two stages of primary and final selections, 9 projects from 17 countries and 23 en-tities were successfully selected, which include space astronomy, space life science and biotechnology, space application technology, micro-gravity fluid phy-sics, combustion science, and Earth science[14]. China will actively use the cap-abilities of CSS pla-tform to organize international big science project and contribute to the develop-ment of space science and technology all over the world.

Manned spaceflight, as a participatory space exploration activity, has a unique advantage as an educational resource and platform. In terms of the science outreach program, an integrated STEM (Science, Technology, Engineering, and Mathema-tics) education system with unique characteristics of manned spaceflight will be built to carry out various science education activities such as scientific exp-eriment projects, popular science competitions, hardware development, and educational demon-strations. It is expected to strengthen public sup-port for the space industry and stimulate young people's interest in manned spaceflight.

It is an important work to transfer new tech-nologies produced in the CSS operation period into new products, new processes, new materials, and to promote new jobs and industries. Establishing a comprehensive platform for the release of scientific and technological achievements will build an effec-tive bridge between CSS knowledge, technologies, and the market. These scientific and technological achieve-ments could be transferred into biopharm-aceuticals, medical health, material manufacturing, advanced energy, disaster relief support, land reso-urce explo-ration. Improvement in the comprehen-sive benefits of CSS will drive industrial reform and promote socio-economic development.

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GU Yidong, GAO Ming, ZHAO Guangheng. Science Research and Utilization Planning of China’s Space Station in Operation Period 2022–2032., 2020, 40(5): 609-614. DOI:10.11728/cjss2020.05.609

E-mail: gxd@nssc.ac.cn

May 25, 2020