Spatio-Temporal Polar-Inclined Space Mission Architecture for a Refined Retrieve of the Earth’s Gravity Field

Future satellite gravity missions (FGMs) have been intensively studied during the last recent years for the era beyond the successful previous GRACE and current GRACE Follow-on satellite missions. Previous studies have investigated the gravity field recovery derived from combined two satellite-pairs (referred here as PI-FGM, a single polar satellite-pair like the GRACE mission combined with another inclined satellite-pair) with different orbital heights of few kilometers and different repeat orbital periods. In this contribution, new innovative idea is introduced by designing the inclined satellite-pair of the FGM at the same orbital height of the polar-type with shifted spatio-temporal (ST-FGM) orbital parameters to avoid any possible collision risk between the two satellite-pairs, polar and inclined, of the FGM architecture. The repeat orbits issue will be taken into consideration through the manuscript and will be set as identical as possible for a fair comparison. The findings through a full-scale simulation analysis show that the new design of shifted spatio-temporal polar-inclined (ST-FGM) mission architecture basically outperforms the two satellite-pairs having different orbital heights (i.e. the PI-FGM mission configuration). Regarding the gravity field recovery, the ST-FGM architecture retrieves the geoid heights with standard deviations of about 17.0 mm providing more isotropic error distribution. An overall improvement by a factor of about 80 and 60 is provided by the ST-FGM and PI-FGM mission architectures, respectively, with respect to the GRACE-like formation and a factor of about 2.4 and 1.8, respectively, with respect to the smoothed gravity solution using the Gaussian filter at radius 400 km. Therefore, the shifted spatio-temporal polar-inclined (ST-FGM) is worthy recommended as stable mission architecture and would be considered as one of the future gravity missions.

Strategic Study on the Development of Space Science in China and Proposals for Future Missions

Since 2011,the Chinese Academy of Sciences(CAS)has implemented the Strategic Priority Program on Space Science(SPP).A series of scientific satellites have been developed and launched,such as Dark Matter Particle Explorer(DAMPE),Quantum Experiments at Space Scale(QUESS),Advanced Space-based Solar Observatory(ASO-S),Einstein Probe(EP),and significant scientific outcomes have been achieved.In order to plan the future space science missions in China,CAS has organized the Chinese space science community to conduct medium and long-term development strategy studies,and summarized the major scientific frontiers of space science as“One Black,Two Dark,Three Origins and Five Characterizations”.Five main scientific themes have been identified for China’s future breakthroughs,including the Extreme Universe,Space-Time Ripples,the Panoramic View of the Sun and Earth,the Habitable Planets,and Biological&Physical Science in Space.Space science satellite missions to be implemented before 2030 are proposed accordingly.

Cutting-Edge Space Exploration Technology Maturity Level Facilitation with Support of Space Debris Removal Missions

Considering current space debris situation in outer space environment,different methods for debris removal missions are proposed.In addition,advanced technologies are needed to be demonstrated for future human space exploration programs.The main issue regarding to these missions is high mission cost for both debris removal missions and space environmental tests to achieve high maturity level for new space-usable technologies.Since,these missions are unavoidable for future of human space activities,a solution which can tackle these challenges is necessary.This paper will address to an idea which has the possibility to give a solution for facilitating technology readiness level(TRL)maturity tests by debris removal mission platform consideration.

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.

High Reliability LM-2F Launch Vehicle for Space Station Mission

As China’s only manned launch vehicle,the LM-2 F Launch vehicle successfully launched the Shenzhou 12 manned spacecraft into its predetermined orbit on June 12,2021,signifying the successful completion of the first manned launch mission in the construction and key technology test stage of China Space Station(CSS).From the launch of the Shenzhou 11 manned spacecraft on October 12,2016 to the launch of Shenzhou 12 in 2021,over the past five years,the LM-2 F launch vehicle has been continuously improved in terms of product reliability through technological innovation and design improvement,and its flight reliability index has increased from 0.97 to 0.98.Based on the new launch mission requirements for the construction stage of CSS,this paper introduces the technological innovation and reliability improvement methods of the LM-2 F from the aspects of design improvement,research methods and process optimization.The LM-2 F launch vehicle will make greater contributions in supporting the construction of CSS with higher reliability and perfect launch success rate.

Coupled Dynamics and Integrated Control for Position and Attitude Motions of Spacecraft:A Survey

Inspired by the integrated guidance and control design for endo-atmospheric aircraft,the integrated position and attitude control of spacecraft has attracted increasing attention and gradually induced a wide variety of study results in last over two decades,fully incorporating control requirements and actuator characteristics of space missions.This paper presents a novel and comprehensive survey to the coupled position and attitude motions of spacecraft from the perspective of dynamics and control.To this end,a systematic analysis is firstly conducted in details to show the position and attitude mutual couplings of spacecraft.Particularly,in terms of the time discrepancy between spacecraft position and attitude motions,space missions can be categorized into two types:space proximity operation and space orbital maneuver.Based on this classification,the studies on the coupled dynamic modeling and the integrated control design for position and attitude motions of spacecraft are sequentially summarized and analyzed.On the one hand,various coupled position and dynamic formulations of spacecraft based on various mathematical tools are reviewed and compared from five aspects,including mission applicability,modeling simplicity,physical clearance,information matching and expansibility.On the other hand,the development of the integrated position and attitude control of spacecraft is analyzed for two space missions,and especially,five distinctive development trends are captured for space operation missions.Finally,insightful prospects on future development of the integrated position and attitude control technology of spacecraft are proposed,pointing out current primary technical issues and possible feasible solutions.

Estimation of far-field wavefront error of tilt-to-length distortion coupling in space-based gravitational wave detection

In space-based gravitational wave detection, the estimation of far-field wavefront error of the distorted beam is the precondition for the noise reduction. Zernike polynomials are used to describe the wavefront error of the transmitted distorted beam. The propagation of a laser beam between two telescope apertures is calculated numerically. Far-field wavefront error is estimated with the absolute height of the peak-to-valley phase deviation between the distorted Gaussian beam and a reference distortion-free Gaussian beam. The results show that the pointing jitter is strongly related to the wavefront error. Furthermore, when the jitter decreases 10 times from 100 nrad to 10 nrad, the wavefront error reduces for more than an order of magnitude. In the analysis of multi-parameter minimization, the minimum of wavefront error tends to Z[5,3] Zernike in some parameter ranges. Some Zernikes have a strong correlation with the wavefront error of the received beam. When the aperture diameter increases at Z[5,3] Zernike, the wavefront error is not monotonic and has oscillation.Nevertheless, the wavefront error almost remains constant with the arm length increasing from 10-1Mkm to 10~3Mkm.When the arm length decreases for three orders of magnitude from 10-1Mkm to 10-4Mkm, the wavefront error has only an order of magnitude increasing. In the range of 10-4Mkm to 10~3Mkm, the lowest limit of the wavefront error is from 0.5 fm to 0.015 fm at Z[5,3] Zernike and 10 nrad jitter.

Progress of Solar Wind Magnetosphere Ionosphere Link Explorer(SMILE) Mission

SMILE(Solar wind Magnetosphere Ionosphere Link Explorer) mission is a joint ESA-CAS space science project. The working orbit is a 19 Re 5000 km HEO with 4 scientific instruments: Soft X-ray Imager(SXI), Ultra-Violet Imager(UVI), Magnetometer(MAG) and Light Ion Analyzer(LIA). SMILE aims to understand the interaction between the solar wind and the Earth's magnetosphere through the images of SXI and UVI and in-situ measurement from LIA and MAG. After the kick-off in 2016, the SMILE project went to Phase A study. The mission adoption is scheduled for November 2018, with a target launch date in 2022–2023.In this paper, the background of the mission, scientific objectives, the design and characteristics of scientific instruments and the mission outline will be introduced in details.

Progress and Prospects of the Strategic Priority Program on Space Science

In May 2018,the second phase of the Strategic Priority Program on Space Science(SPP II)was officially approved by the Chinese Academy of Sciences,in view of the significant scientific achievements of the first phase of the Strategic Priority Program on Space Science(SPP I)which includes 4 space science missions:the Dark Matter Particle Explorer(DAMPE),ShiJian-10(SJ-10),Quantum Experiments at Space Scale(QUESS)and Hard X-ray Modulation Telescope(HXMT).Aiming to address fundamental scientific questions,SPP II focuses on two major themes:How the universe and life originate and evolve and What is the relationship between the solar system and human beings.In areas that Chinese scientists have advantages,new space science missions including Graviational wave high-energy Electromagnetic Counterpart All-sky Monitor(GECAM),the Advanced space-based Solar Observatory(ASO-S),the Einstein Probe(EP),and Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)have been approved in the framework of SPP II.This paper presents the research highlights of the SPP I,introduces the recent progress of SPP II,and puts forward the prospects for future development.

China's Space Science Program(2025-2030):Strategic Priority Program on Space Science(Ⅲ)

The Strategic Priority Program(SPP)on Space Science,which is under the leadership of the Chinese Academy of Sciences(CAS),has established China’s space science satellite series from scratch.A number of major scientific achievements have been made by the first phase of the Program(SPPⅠ),while SPPⅡhas been currently being implemented.The future development of space science needs urgent top-level planning and advanced layout to clarify the overall goal and investment portfolio from 2025 to 2030.We will briefly introduce the initiative and possible space science missions of SPPⅢ,including the preparatory work which already started in July 2021.Following the effective administrative tradition since SPPⅠ,National Space Science Center(NSSC,CAS)is responsible for the whole procedure,including soliciting,assessment,and implementation of SPPⅢ.Brief information on the 13 candidate missions will be described,including missions in the fields of astronomy&astrophysics,exoplanets,heliophysics and planetary&Earth science,respectively.

Achievements of Space Scientific Experiments Aboard SJ-8 Satellite

As scientific experiment payloads,microgravity experiments of fluid physics,life science,combustion science,physics and accelerator measurement were conducted on board the Chinese recoverable satellite SJ-8 during 18-day orbital flight.The experimental payloads and an experiment support system constituted the microgravity experiment system of the flight mission.This article has presented the briefs of the scientific achievements of these space experiments,the composition and performance of the Microgravity Experimental System(MES) and the general picture of the overall flight mission,respectively.

面向战区联合作战的空间需求响应任务规划

针对战区联合作战中的空间需求响应问题,描述了面向战区联合作战的空间需求响应任务规划的背景;从空间资源能力、空间需求响应机制、空间需求响应效益和代价等方面,分析了空间需求响应任务规划所需考虑的主要因素;定义并描述了任务规划模型,设计了任务规划计算方法,并结合战区联合作战实际进行了案例仿真与分析,验证了模型和方法的有效性,为战区联合作战中空间需求的有效响应提供了理论和方法支撑。

航天任务分析与设计工业软件发展战略分析

航天工业设计软件是我国航天事业当前亟需重点攻克的“卡脖子”技术领域。航天任务分析与设计软件是航天任务全寿命周期的关键软件,是航天工业设计软件体系中主根系软件。本文首先对其中最具代表性的软件产品——美国STK的发展历程、主要功能特点进行总结剖析;在此基础上从模型算法创新、软件协作开发和数字化发展趋势等方面概括STK的发展启示;进一步通过该类软件的特点分析,结合探索实践历程,对国产软件替代的可行性进行分析研判;最后提出了我国自主软件的发展思考和对策建议,包含软件研发模式、软件推广与应用、国家政策支持等方面。

Retrospect to Human Deep Space Exploration History and Its Prospect in China

The definition, goal and impacts of deep space exploration are summarized. After a retrospect to past deep exploration activities of human being to date, both recent deep space missions and future missions in 5 years are also listed. There are also brief introductions about the future strategic plans of NASA, ESA, RAKA, JAXA and ISRO. Then authors analyze some important features of global deep space exploration scheme. Key technologies of deep space exploration are also determined. The status of China deep exploration plan is introduced including CE-1 lunar orbiter, the subsequent China Lunar Exploration Program, especially proposal for the second stage of China Lunar Exploration Program, Mars exploration program of China with Russia Kuafu mission, Hard X-Ray Modulated Telescope, Space Solar Telescope. At the end, some suggestions for China future deep space exploration are made.

载银抗菌材料在载人航天水处理任务中的应用前景

银具有广谱抗菌、低毒无耐药性的特点,是一种可应用于长期载人航天任务水处理系统的优选抗菌剂。本文首先介绍了银的抗菌机理,分别从抗菌剂和载体材料两个角度对载银抗菌材料进行了分类,重点关注载银抗菌材料的缓释性能,并从银离子负载优化、载体材料预处理和负载制备工艺优化三个角度总结了现阶段增强载银抗菌材料缓释性能的途径。结合地面水处理工程中载银抗菌材料的应用实际,现有载银抗菌材料的缓释效果有限,且银离子释放浓度低。基于长期载人航天任务中水处理系统杀菌抑菌的应用工况,要求载银抗菌材料能够实现长效稳定缓慢释放,基材性能稳定且无次生污染物溶出,并可耐受航天发射上行力学要求。如能实现,不仅是对现有空间站洁净水电解加银技术的补充,更对我国长期载人航天任务的多场景抑菌杀菌具有重要应用意义。

载人月球探测混合云架构体系仿真系统研究

针对载人月球探测工程任务需求,设计了一种基于混合云架构的体系仿真系统,实现了辅助设计、方案验证和协助任务等功能应用。分别从任务设计和应用模式角度分析了体系仿真系统功能需求;根据需求给出体系仿真系统总体架构,采用仿真平台和仿真支持库统筹建设的方式,完成了系统开发与集成;提出了针对体系仿真系统建设涉及的体系建模、任务规划、推演展示、效能评估和系统联动与扩展关键技术实现方案;应用该系统实现了对典型载人月面活动场景的仿真,得到了关键参数模拟推演结果,验证了体系仿真系统各项功能有效性和正确性;最后给出了思考和展望。该体系仿真系统可支撑未来载人月球探测相关任务开展发展论证和综合评估验证,能够为同类系统开发提供方案参考。

国际空间站舱外多载荷运行任务规划

空间站舱外载荷平台支持部署众多不同类型的载荷,为开展大规模空间科学研究提供了机会.但随着舱外载荷数量及相应任务量的不断增加,且在受限于资源约束的情况下,需要制定科学合理的任务规划,以提高舱外载荷的工作效率.针对舱外多载荷运行任务规划方法,深入分析了国际空间站舱外载荷任务规划现状,重点分析了其舱外载荷平台、载荷类型及特点和多载荷运行任务规划方法,分析当前任务规划策略、方法及未来发展方向.根据中国空间站舱外载荷平台特点,从载荷总体设计和运行任务规划方法等方面为中国空间站后续舱外多载荷系统运行任务规划提供参考和建议.

航天任务系统容灾备份技术应用

传统航天任务系统面临多代并存、部署不灵活、容灾手段不完善、应急切换速度慢等问题,难以适应后续云架构下一体化融合管控模式,必须解决容灾备份体系设计和系统级迁移切换难题。分析了传统航天任务系统存在的安全风险和特点规律,设计了云架构下异地容灾备份体系,提出了虚拟化迁移、网络层控制改造、应用层域名改造、通信配置集成管理等解决方法,形成了迁移部署流程和快速切换建链方法。试验表明,相比传统备份手段,云架构下异地容灾备份系统能够有效缩短系统级部署与切换时间至3小时,明显提升异常应对能力,可为后续一体化管控模式下容灾备份体系建设与特殊场景应用提供技术支持。

深空探测任务进展与展望

本文全面综述了国际深空探测任务设计的最新进展,涵盖月球探测、大行星探测及小天体探测领域。月球探测方面,介绍了美国Artemis计划、中国探月工程等地月空间战略布局;大行星探测方面,回顾了水星、金星、火星及木星、土星等外行星的探测历史与现状;小天体探测方面,探讨了其技术难点及科学意义,详述了小行星飞越、环绕、采样和撞击等任务。在此基础上,总结了深空探测任务的启示与发展趋势;结合我国深空探测能力与国际行星科学发展,提出相关任务建议与设想,为我国未来深空探测任务设计提供参考。

基于任务效能评价张量进化的航天器任务规划

航天器在空间探索时需要面对各种多任务场景,复杂的任务耦合关系和航天器轨迹约束给任务规划带来困难。本文提出了基于任务效能评价张量进化的航天器任务规划方法,利用张量形式来描述任务规划中任务点间转移轨迹与前序任务集的耦合关系,精确地评价不同任务规划方案下的转移轨迹代价和任务收益,从而有效地提高了任务规划效能,并极大缩减了任务规划的计算量。