Recent Progress in Space Science and Applications on Chinese Space Station in 2022–2024

Chinese Space Station(CSS)has been fully deployed by the end of 2022,and the facility has entered into the application and development phase.It has conducted scientific research projects in various fields,such as space life science and biotechnology,space materials science,microgravity fundamental physics,fluid physics,combustion science,space new technologies,and applications.In this review,we introduce the progress of CSS development and provide an overview of the research conducted in Chinese Space Station and the recent scientific findings in several typical research fields.Such compelling findings mainly concern the rapid solidification of ultra-high temperature alloy melts,dynamics of fluid transport in space,gravity scaling law of boiling heat transfer,vibration fluidization phenomenon of particulate matter,cold atom interferometer technology under high microgravity and related equivalence principle testing,the full life cycle of rice under microgravity and so forth.Furthermore,the planned scientific research and corresponding prospects of Chinese space station in the next few years are presented.

A guidance strategy for rendezvous and docking to the space station in the Earth-Moon NRHO orbit

With the development of space technology,it is possible to build a space station in Earth-Moon space as a transit for Earth-Moon round-trip and entering in the deep space.Rendezvous and docking is one of the key technologies for building an Earth-Moon space station.A guidance strategy for rendezvous and docking from the Earth orbit to the space station in the Earth-Moon NRHO orbit is proposed in this paper,which is suitable for engineering applications.Firstly,the rendezvous and docking process is divided into three sections,i.e.,the large-range orbit transfer section,far-range guidance section,and close-range approaching section.The suitable terminal of large-range orbit transfer is selected according to the eigenvalue of NRHO orbit state transition matrix.The two-impulse guidance method based on the relative motion equation in the three-body problem is adopted for the far-range guidance section.The impulse time and amplitude are solved with the optimization algorithm.The linear constant three-body relative motion equation is proposed for the close-range approaching section,and the rendezvous and docking is completed by a two-stage linear approximation.Finally,a simulation analysis is carried out,and the simulation results show that the adopted dynamics equations and the designed guidance law are effective,and the three flight phases are naturally connected to accomplish the rendezvous and docking mission from the Earth orbit to the space station on the Earth-Moon NRHO.

Energy conversion materials for the space solar power station

Since it was first proposed,the space solar power station(SSPS)has attracted great attention all over the world;it is a huge space system and provides energy for Earth.Although several schemes and abundant studies on the SSPS have been proposed and conducted,it is still not realized.The reason why SSPS is still an idea is not only because it is a giant and complex project,but also due to the requirement for various excellent space materials.Among the diverse required materials,we believe energy materials are the most important.Herein,we review the space energy conversion materials for the SSPS.

Monte Carlo calculation of the exposure of Chinese female astronauts to earth’s trapped radiation on board the Chinese Space Station

With the development of China’s crewed space mission,the space radiation risk for astronauts is increasingly prominent.This paper describes a simulation of the radiation doses experienced by a Chinese female voxel phantom on board the Chinese Space Station(CSS)performed using the Monte Carlo N-Particle(MCNP)software.The absorbed dose,equivalent dose,and effective dose experienced by the voxel phantom and its critical organs are discussed for different levels of shielding of the Tianhe core module.The risk of space-radiation exposure is then assessed by comparing these doses with the current risk limits in China(the skin dose limit for short-term low-earth-orbit missions)and the NASA figures(National Council on Radiation Protection and Measurements Report No.98)for female astronauts.The results obtained can be used to guide and optimize the radiation protection provided for manned space missions.

Physics package based on intracavity laser cooling ^(87)Rb atoms for space cold atom microwave clock

This article proposes a new physics package to enhance the frequency stability of the space cold atom clock with the advantages of a microgravity environment. Clock working processes, including atom cooling, atomic state preparation,microwave interrogation, and transition probability detection, are integrated into the cylindrical microwave cavity to achieve a high-performance and compact physics package for the space cold atom clock. We present the detailed design and ground-test results of the cold atom clock physics package in this article, which demonstrates a frequency stability of 1.2×10^(-12) τ^(-1/2) with a Ramsey linewidth of 12.5 Hz, and a better performance is predicted with a 1 Hz or a narrower Ramsey linewidth in microgravity environment. The miniaturized cold atom clock based on intracavity cooling has great potential for achieving space high-precision time-frequency reference in the future.

Optimization Strategies of Beijing Elderly Care Service Stations Based on Questionnaire Survey Method: A Case Study of Zhanlan Road Street of Xicheng District

4 elderly care service stations in Zhanlan Road Street,Xicheng District,Beijing are selected,and questionnaires are designed and distributed to the surrounding elderly population to understand their needs and satisfaction with the station environment.By observing elderly care service stations on site,the characteristics,obstacles,and shortcomings of the environment are recorded,and relevant data are collected and analyzed,such as the characteristics of the elderly population being interviewed,the planning and design data of the station environment,and the distribution of service facilities.The overall characteristics of the spatial environment of elderly care stations are summarized,and renovation measures and optimization suggestions are provided for the current shortcomings,thereby providing some basis for the spatial design of community elderly care service stations in the future.

Recent Progress in Space Science and Applications of China’s Space Station in 2020-2022

China scheduled to complete the assembly of the T-shaped Tiangong Space Station in 2022,and will enter a new stage of utilization.There are more than 20 experiment racks inside the modules,and more than 50 external onboard payloads mounting spaces,which will support large-scale science and technology experiments during the operation.The development of internal experiment racks and external research accommodations approved during the construction has been completed,of which 4 racks in Tianhe core module,including High Microgravity Level research Rack(HMLR)and Container-less Materials Processing Rack(CMPR),have finished on-orbit tests;while other racks in Wentian and Mengtian experiment modules are under comprehensive ground tests.The Chinese Space Survey Telescope(CSST)has advanced much in the last two years with 24 pre-launch research projects funded and 4 joint science center built in preparation for CSST’s future scientific observations and operations.The systematic research planning for China’s Space Station(CSS)during 2022-2032 is updated with the researches classified into four important areas:space life sciences and human research,microgravity physical sciences,space astronomy and Earth science,and new space technologies and applications.According to the planning,more than 1000 experiments are expected to perform in CSS during the operating period.Overall,the CSS utilization missions are proceeding as planned,which will contribute to the major scientific or application output and have a positive impact on the quality of life on Earth.

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

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 environment,space application technology,etc.In combination with the latest development trend of space science and technology,China will continue to update planning for science research and technology development,carry out project cultivation,payload R&D,and upgrade onboard and ground experiment supporting systems to achieve greater comprehensive benefits in science,technology,economy,and society。

Space station short-term mission planning using ontology modelling and time iteration

This paper studies the problem of the space station short-term mission planning, which aims to allocate the executing time of missions effectively, schedule the corresponding resources reasonably and arrange the time of the astronauts properly. A domain model is developed by using the ontology theory to describe the concepts, constraints and relations of the planning domain formally, abstractly and normatively. A method based on time iteration is adopted to solve the short-term planning problem. Meanwhile, the resolving strategies are proposed to resolve different kinds of conflicts induced by the constraints of power, heat, resource, astronaut and relationship. The proposed approach is evaluated in a test case with fifteen missions, thirteen resources and three astronauts. The results show that the developed domain ontology model is reasonable, and the time iteration method using the proposed resolving strategies can successfully obtain the plan satisfying all considered constraints.

ROBUST H_∞ DESIGN OF THE ATTITUDE CONTROL/MOMENTUM MANAGEMENT SYSTEM FOR A SPACE STATION

Through input-output decom position of structured param eter uncertainties of the con- trolled plant, the robustcontrolproblem ofspace station attitude system w ith param eteruncertainties is converted to a conventionaldisturbance rejection H∞ controller design problem , then a full-state feedback H∞ robustcontrollerisform ulated, w hich can be solved using the Glover-Doyle algorithm . The proposed m ethod w asapplied to the attitude control/m om entum m anagem ent (ACMM) system ofa space station, and tw o kinds of param eter uncertainties w hich appear m ost frequently in space- craftengineering w ere considered. Sim ulation results show ed efficiency ofthe given m ethod.

Surface Charging Controlling of the Chinese Space Station with Hollow Cathode Plasma Contactor

A highly charged manned spacecraft threatens the life of an astronaut and extravehicular activity, which can be effectively reduced by controlling the spacecraft surface charging. In this article, the controlling of surface charging on Chinese Space Station （CSS） is investigated, and a method to reduce the negative potential to the CSS is the emission electron with a hollow cathode plasma eontactor. The analysis is obtained that the high voltage （HV） solar array of the CSS collecting electron current can reach 4.5 A, which can be eliminated by emitting an adequate electron current on the CSS. The theoretical analysis and experimental results are addressed, when the minimum xenon flow rate of the hollow cathode is 4.0 sccm, the emission electron current can neutralize the collected electron current, which ensures that the potential of the CSS can be controlled in a range of less than 21 V, satisfied with safety voltage. The results can provide a significant reference value to define a flow rate to the potential controlling programme for CSS.

Computed Tidal Relativistic Red-Shifts of Frequency Standards on Earth and in Space Stations

Frequencies of frequency standards are shifted by the local static gravity red shifts and also modulated by the tidal relativistic red shifts. We compute the tidal relativistic red shifts using a time-domain method and present the numerical results for the National Institute of Metrology （NIM） in Beijing, Laboratoire National de Metrologie et Essais-Systeme de References Temps-Espaee （LNE-SYRTE） in Paris and Physikalisch-Teehnische Bundesanstalt （PTB） in Braunschweig. The differences of the tidal relativistic red shift approach as large as 1.1 × 10^-16 when frequency standards at NIM are compared with those at SYRTE and PTB. Moreover, the tidal relativistic red shifts of frequency standards in space stations are also computed.

Space Research Plan of China's Space Station

China's manned spaceflight missions have been introduced briefly,and the research planning of space sciences for China's Space Station(CSS) has been presented with the topics in the research areas,including:life science and biotechnology,microgravity fluid physics and combustion science,space material science,fundamental physics,space astronomy and astrophysics,earth sciences and application,space physics and space environment,experiments of new space technology.The research facilities,experiment racks,and supporting system planned in CSS have been described,including:multifunctional optical facility,research facility of quantum and optic transmission,and a dozen of research racks for space sciences in pressurized module,etc.In the next decade,significant breakthroughs in space science and utilization will hopefully be achieved,and great contributions will be made to satisfy the need of the social development and people's daily life.

Space Resources Planning and Design of Rail Transit Station in Chongqing

According to the study on 39 sites of rail transit Line 3 in Chongqing, the sites are classifi ed into three types: residential type, business center type, traffi c hub type in this paper. The study shows that the sites have many problems such as discordance of land use, severity of spatial segregation, low rate of site utilization. To solve these problems, development approaches of site space resources within 1,000 m around the site area are further explored. The approaches include four aspects: characteristics of land use, functional composite, walking guide and shuttle transportation. In addition, appropriate planning and design methods are proposed.

Artistic Space Design of Subway Station Based on Regional Characteristics

On the basis of existing problems in the spatial design of subway station, this paper explored the principles that regional culture involves in the artistic space design of subway station; based on the analysis of three main design sections and site cases-spatial interface, public art and color, the paper also discussed the artistic application and design embodiment of regional culture characteristics reflected in every element of subway station space design, so as to provide a consolidated design example for subway station space design featuring regional characteristics in the future.

Space Environment Measurements and Applications on the Tianhe Core Module of China Space Station

Tianhe Core Module of China Space Station(CSS)equips a set of instruments consisting of a Particle Fluxes and Solar Activity Detector(PFSAD)and two Atmospheric Density Multi-directional Detectors(ADMDs).The PFSAD is to measure X-rays from the Sun and energetic particles in the low-latitude and low altitude regions,including electrons,protons,and helium ions.The ADMDs are to measure thermospheric atmospheric density.The instruments provide real-time data of the orbital space environment,including solar flares,energetic particle variation and thermospheric density enhancement.All the data contribute to the CSS space weather service for mission control and astronaut’s safety.The paper gives preliminary analyses of the space environment measurements from the PFSAD and the ADMDs.By further analysis,the 1024-channel fine spectra of the solar X-ray can be used to study the mechanism of solar flares and their impacts on the Earth’s atmosphere.Data accumulation will be helpful for analyzing mid-term and long-term variations of the South Atlantic Anomaly and atmosphere density.Furthermore,the data are useful to calibrate previous empirical models and establish new models to study the space environment.

Multi-Layer and Multi-Objective Optimization Design of Supporting Structure of Large-Scale Spherical Solar Concentrator for the Space Solar Power Station

Space solar power station is a novel renewable energy equipment in space to provide the earth with abundant and continuous power.The Orb-shaped Membrane Energy Gathering Array,one of the alternative construction schemes in China,is promising for collecting space sunlight with a large-scale spherical concentrator.Both the structural and optical performances such as root mean square deformation,natural frequency,system mass,and sunlight blocking rate have significant influences on the system property of the concentrator.Considering the comprehensive performance of structure and optic,this paper proposes a novel mesh grid based on normal polyhedron projection and spherical arc bisection for the supporting structure to deal with the challenge of the large-scale structural modular design.For both achieving low system mass and high surface precision,a multilayer and multi-objective optimization model is proposed by classifying the supporting structure into different categories and optimizing their internal and external diameters.The Particle Swarm Optimization algorithm is adopted to find optimal sectional dimensions of the different kinds of supporting structure.The infinite model is also established and structural analysis is carried out,which are expected to provide a certain reference for the subsequent detailed structural design.The numerical results indicate that the spherical concentrator designed by the novel mesh grid would obtain as high as 94.37%sunlight collection efficiency.The supporting structure constructed with the multiple layers would reduce the system quality by 6.92%,sunlight blocking rate by 28.54%,maximum deformation by 41.50%,and root mean square by 9.48%to the traditional single layer,respectively.

Evolution of Commercial Space near the Subway Stations of Community Type Based on Self-Organization Theory: A Case Study of Chengdu Wannianchang Subway Station

The subway stations of urban community type are not only main nodes in the urban traffic network, but also important places for peopled daily life. Widi the rapid development of urban metro and urban economy, the commercial space near tiie subway station has become the focus of urban planning and urban spatial development, and commercial self-oiganization pkys an important role in the development of commercial operations, commercial structures, and commercial scales, so how to make effective use of the inherent laws of the commercial space evolution, and further guide the rational development of community businesses needs more attention and research. This paper takes Chengdu Wannianchang Subway Station as an example to study the evolution stage, influencing factors, evolution characteristics and laws of the neatby commercial space. Moreover, suggestions were put forward such as coordinating competition and collaboration, optimizing space design and management, co-directional self-organization and heter-oiganizations, in order to provide a new reference for the healthy and ordedy development of the neighboring commefdal space near the subway stations of community type.

基于CiteSpace的国内外站域交通空间的适老性研究

随着全球老龄化进程的进一步加快,中国作为世界上老龄人口最多的国家之一,城市化和老龄化的共同加剧,使得老年人出行需求成为社会关注的重点。尽管由老龄化带来的各种社会问题已经引起全社会的关注并且出台了许多适老化政策,但是由于中国老年人口基数大增长快,新政策、新理念的贯彻落实不到位,老年人在交通空间的出行方面仍存在困难,尤其是当下站域交通空间的适老性应对仍较为欠缺。文章以乐龄友好出行为切入点,通过对2007—2022年国内外站域交通空间适老性研究成果的梳理,发现:①国外对于站域交通空间适老性研究起步早且趋于成熟,国内方面起步晚于国外,在政府及社会的多方面支持下适老性研究虽呈现爆发式增长,但针对交通适老的研究处于发展前期未形成发散的研究网络;②国内站域交通空间适老性研究还停留在无障碍设计及通用设计宏观方面,且研究主题分布较为集中缺乏对老年人心理需求的研究,而国外在该领域的研究呈现交叉互动,方向也更加微观、多元。

Alpha Magnetic Spectrometer (AMS02) experiment on the International Space Station (ISS)

The Alpha Magnetic Spectrometer experiment is realized in two phases. A precursor flight (STS-91)with a reduced experimental configuration (AMS01) has successfully flown on space shuttle Discovery in June 1998.The final version (AMS02) will be installed on the International Space Station (ISS) as an independent module inearly 2006 for an operational period of three years. The main scientific objectives of AMS02 include the searches forthe antimatter and dark matter in cosmic rays. In this work we will discuss the experimental details as well as the im-proved physics capabilities of AMS02 on ISS.