Return Mission Research Articles

Research on Data Recorder of Sample Return Missions Against High Overload

Abstract In this paper, we present the design and implementation of an ARM-based data storage system tailored to meet the extensive data acquisition, storage, and hard landing recovery requirements of aerospace sampling and return missions. The system employs the STM32 as the primary control chip and utilizes the RS422 interface to transmit two analog signals and one image data signal. Data is stored on an eMMC chip via the eMMC 5.1 protocol. Additionally, composite buffer materials were used for protection. The mechanical casing of the data recorder was simulated using the finite element software ANSYS, and its overload resistance was validated through Machete hammer impact test. Experimental results demonstrate that the system can achieve reliable data storage at 10 Mb/s, withstand overload accelerations exceeding 4000g. Experiments have demonstrated that the system operates without packet loss or bit errors, providing a solution for high-reliability, high-speed, large-capacity, and compact data storage in the high-overload environments of aerospace sampling and return missions.

Onboard autonomous mission generation method based on user preference

This paper presents a method for autonomous onboard mission generation of Earth observation imaging satellites based on user preferences. The paper develops a planning database to store the previous user mission requirements, and proposes a database updating algorithm to track the changes in user preferences. The paper also proposes a mission generation method based on the planning database, which predicts target priorities and imaging methods. Finally, a mission allocation strategy is used to assign newly generated missions to the appropriate satellites. Simulations results show that the proposed method can effectively improve the utilization of satellite resources and thereby obtain higher mission return.

Simulation and analysis of chest loads on crews during Lunar-Earth re-entry returns.

The safety of crews is the primary concern in the manned lunar landing project, particularly during re-entry as the manned spacecraft returns from a direct Lunar-Earth trajectory. This paper analyzed the crew's chest biomechanical response to assess potential injuries caused by acceleration loads during the re-entry phase. Initially, a sophisticated finite element model of the chest was constructed, whose effectiveness was verified by experiments involving vertebral range of motion, rib lateral rupture, and chest frontal impact. The model was then subjected to the return re-entry loads simulating the Apollo and Chang'e 5 T1 (CE-5T1) test returner to specifically analyze the correlation between the acceleration load and the injury of the crew's chest tissues and organs. The results indicate that the biomechanical response of crew chest bone tissue under the two return missions is within the threshold value and will not directly cause damage. Compared to the Apollo mission, the CE-5T1 mission's load poses a higher risk to internal organs. These findings can enhance the crew's safety and provide reliable assurance for future space exploration.

From Experimental Animal to Companion: Astronaut`s Behavioural Health and Risk Management for Mars Exploration

Space science has been developed through past and current missions of the International Space Station (ISS) and Tiangong Space Station (TSS) in low Earth orbit and on the lunar surface. Numerous missions have used animals on test flights to better understand the physiological dangers of space flight for humans. A contemporary focus of space exploration is long-duration crewed travel to establish a Moon station and reach Mars. The astrotechnology of the human-less spaceflights (USA, Russia, ESA, UAE, China, and India) launched in 1965 (Mariner 4), has advanced enough to support the progressive colonisation of the Red Planet with investigating equipment (Perseverance rover, Ingenuity helicopter, Hope orbiter, Tianwen-1 orbiter, and Chinese lander-rover). Are humans, then, ready to explore for Mars soon? What are major hazards that still need to be solved? Can animals play a novel role for humans in deep space travel? While the five factors of altered gravity, radiation, confinement (isolation), distance from Earth, and unknown hostile environments have been analysed in the scientific field of space medicine, this paper explores the biological ripple effects of animal astronauts to mitigate risks for human astronauts. The countermeasures of the psychological well-being and space community security are determined considering the potential role of animals in reducing the emergence rate of behavioural health and performance decrements (loneliness, mental and emotional strain, fear, lethargy, lack of enthusiasm, and violence). This paper argues a new hypothesis that if the engineering aspects of animal (dog) support does not reduce the scientific capabilities, the cognitive policy of a �human-pet companionship� apart from the historically traditional pattern of �experimental animal� can benefit the mental, social, and physical resilience of the Martian astronauts during the return mission (2.5�3 years).

THE MECHANICAL PROPERTIES AND FAILURE MODE OF SIMULATED LUNAR ROCK BY IN SITU TEMPERATURE REAL-TIME ACTION OF LUNAR-BASED

To achieve in situ condition-preserved coring of the lunar surface and deep lunar rocks and a return mission, it is necessary to explore the mechanical properties and failure modes of simulated lunar rocks that have physical and mechanical properties approximately equivalent to those of mare basalt under simulated lunar temperature environments ([Formula: see text][Formula: see text]C to 200[Formula: see text]C). To this end, real-time uniaxial compression tests were conducted on simulated lunar rocks under corresponding in situ temperature conditions, and the mechanical properties, deformation characteristics, micromorphology, and failure modes were analyzed. Based on the macroscopic analysis, as the environmental temperature decreases, the uniaxial compressive strength, peak strain, and peak strain duration of simulated lunar rocks exhibit a nonlinear increasing trend, with maximum increases of 33.00[Formula: see text], 36.16[Formula: see text], and 49.25[Formula: see text] from those at room temperature, respectively. Based on microscopic analysis, the intergranular fractures run through the entire samples under the environmental temperature. As the environmental temperature increases, intergranular and transgranular fractures coexist, and layered fractures appear at high temperatures. At the same time, some samples exhibit undulating and stepped morphologies caused by shear stress. For the fractal dimension of a simulated lunar rock main fracture surface, the fractal dimension of the actual angle and the corrected angle increase first and then decrease with increasing environmental temperature, and the maximum error of the two is only 1.84[Formula: see text]. The overall fractal dimension ranges from 2.02 to 2.28, and the fractal dimension under real-time high-temperature conditions is higher than that under real-time low-temperature conditions. In addition, the failure mode of the simulated lunar rocks under real-time in situ temperature changes is a combined tensile–shear failure mode with shear failure (primary) and tensile failure (secondary). The above research results are expected to be applied to in situ condition-preserved coring in extreme lunar environments and provide a scientific basis for the design and development of in situ condition-preserved coring robot systems for the extreme environment of deep space.

Fuel-Optimal Powered Descent Guidance for Hazardous Terrain

Future interplanetary missions will carry more and more sensitive equipment critical for setting up bases for crewed missions. The ability to manoeuvre around hazardous terrain thus becomes a critical mission aspect. However, large diverts and manoeuvres consume a significant amount of fuel, leading to less fuel remaining for emergencies or return missions. Thus, requiring more fuel to be carried onboard. This work presents fuel-optimal guidance to avoid hazardous terrain and safely land at the desired location. We approximate the hazardous terrain as step-shaped polygons and define barriers around the terrain. Using an augmented cost functional, fuel-optimal guidance command, which avoids the terrain, is derived. The results are validated using computer simulations and tested against many initial conditions to prove their Effectiveness.

Trace-element analysis of mineral grains in Ryugu rock fragment sections by synchrotron-based confocal X-ray fluorescence

A fundamental parameter-based quantification scheme for confocal XRF was applied to sub-micron synchrotron radiation X-ray fluorescence (SR-XRF) data obtained at the beamline P06 of the Deutsches Elektronen-Synchrotron (DESY, Hamburg, Germany) from two sections C0033-01 and C0033-04 that were wet cut from rock fragment C0033 collected from Cb-type asteroid (162173) Ryugu by JAXA’s Hayabusa2 mission. Trace-element quantifications show that C0033 bulk matrix is CI-like, whereas individual mineral grains (i.e., magnetite, pyrrhotite, dolomite, apatite and breunnerite) show, depending on the respective phase, minor to strong deviations. The non-destructive nature of SR-XRF coupled with a new PyMca (a Python toolkit for XRF data analysis)-based quantification approach, performed in parallel with the synchrotron experiments, proves to be an attractive tool for the initial analysis of samples from return missions, such as Hayabusa2 and OSIRIS-REx, the latter returning material from a B-type asteroid (101955) Bennu in 2023.Graphical

Assessment of Radiative Heating for Hypersonic Earth Reentry Using Nongray Step Models

Accurate prediction of the aerothermal environment is of great significance to space exploration and return missions. The canonical Fire II trajectory points are simulated to investigate the radiative transfer in the shock layer for Earth reentry at hypervelocity above 10 km/s using a developed radiation–flowfield uncoupling method. The thermochemical nonequilibrium flow is solved by an in-house PHAROS Navier–Stokes code, while the nongray radiation is integrated by the tangent slab approximation, respectively, combined with the two-, five-, and eight-step models. For the convective heating, the present results agree well with the data of Anderson’s relation. For the radiative heating, the two-step model predicts the closest values with the results of Tauber and Sutton’s relationship, while the five- and eight-step models predict far greater. The three-step models all present the same order of magnitude of radiative heating of 1 MW/m2 and show a consistent tendency with the engineering estimation. The Planck-mean absorption coefficient is calculated to show the radiative transfer significantly occurs in the shock layer. By performing the steady simulation at each flight trajectory point, the present algorithm using a nongray step model with moderate efficiency and reasonable accuracy is promising to solve the real-time problem in engineering for predicting both convective and radiative heating to the atmospheric reentry vehicle in the future.

Design and implementation of a structural subsystem ofChang’e-5 probe

<p indent=0mm>The Chang’e-5 probe has achieved the first unmanned lunar surface sampling and return mission in China. The probe faced several technical challenges, including complex configuration, high lightweight and precision requirements, and strict environmental and load conditions. The design scheme of the whole structure and substructure of the probe is briefly introduced in this paper. Particularly, for key technical problems, such as the lunar surface sampling, lunar orbital rendezvous and docking, and returning lunar samples to the earth at high speed <sc>(11 km/s,</sc> close to the second cosmic velocity), this paper expounds on the research contents of the lightweight of the lander and ascender, high-precision composites structure design method, structure scheme of the takeoff platform with the integrated heat-resistant and load-bearing technology, design of the returner bond buffer to adapt to the impact of oblique landing, and labyrinthine thermal-seal design of the hatch door. The results of the mission show that the design of the structural subsystem of the Chang’e-5 probe is a complete success.

Overall Scheme Trade-off Design of Chang’E-5 Mission

In response to the requirements of lunar sampling and return mission, based on the development of our country’s launch vehicle and the technical foundation in the first and second phases of the lunar exploration project, a multi-planned and multi-round iterative trade-off analysis has been made on the overall plan of the detector, the composition of the functional modules, the launch method, the flight process, etc., and the module composition, main flight process and “Chang’E-5” engineering design process of “Chang’E-5” detector have been gradually optimized and determined. The result fully proves that the scheme is in line with our country’s lunar exploration project development plan and aerospace technology development expectations, and thus is advanced and feasible. The NAFVO trade-off design method adopted in the design process can provide a useful reference for the design of complex and large-scale aerospace engineering schemes.

A New Martian Crater Chronology: Implications for Jezero Crater

Abstract Crater chronologies are a fundamental tool to assess the relative and absolute ages of planetary surfaces when direct radiometric dating is not available. Martian crater chronologies are derived from lunar crater spatial densities on terrains with known radiometric ages, and thus they critically depend on the Moon-to-Mars extrapolation. This extrapolation requires knowledge of the time evolution of the impact flux, including contributions from various impactor populations, factors that are not trivially connected to the dynamical evolution of the early Solar System. In this paper, we will present a new Martian crater chronology based on current dynamical models, and consider the main sources of uncertainties (e.g., impactor size–frequency distribution; dynamical models with late and early instabilities, etc.). The resulting “envelope” of Martian crater chronologies significantly differs from previous chronologies. The new Martian crater chronology is discussed using two interesting applications: Jezero crater’s dark terrain (relevant to the NASA Mars 2020 mission) and the southern heavily cratered highlands. Our results indicate that Jezero’s dark terrain may have formed ∼3.1 Ga, i.e., up to 0.5 Gyr older than previously thought. In addition, available crater chronologies (including our own) overestimate the number of craters larger than 150 km on the southern highlands, suggesting either that large craters have been efficiently erased over Martian history or that dynamical models need further refinement. Further, our chronology constrains the age of Isidis basin to be 4.05–4.2 Ga and that of the Borealis basin to be 4.35–4.40 Ga; these are predictions that can be tested with future sample and return missions.

An adaptive optimization algorithm based on clustering analysis for return multi-flight-phase of VTVL reusable launch vehicle

The return multi-flight-phase trajectory optimization of reusable launch vehicle is the key problem of vertical takeoff and vertical landing (VTVL) technologies. In order to solve the problem of ac-curate pinpoint soft landing in the high-dimensional parameter space composed of complex multi-variables and multi-constraints, this paper proposes a strategy of automatic parameter identification and classification and adaptive allocation of optimization algorithms based on clustering analysis. Firstly, state transition matrix of the terminal constraint variables relative to the design variables in the high-dimensional parameter space is obtained, which describes the sensitivity of the terminal constraint variables to the perturbation of the design variables. Then, K-means clustering algorithm is used to classify the sensitivity of the data elements in the state transition matrix, and the linear and nonlinear constraint variables and design variables together with linear state transition matrix are obtained according to the given linearity criterion. Finally, different optimization algorithms are allocated adaptively according to the linear and nonlinear characteristics of different parameter variables. Numerical simulation shows that the proposed algorithm can effectively deal with complex landing constraints, which has well accuracy, convergence and computational efficiency, and reduces the dimension and complexity of parameter space for the return trajectory optimization problem. Besides, the proposed algorithm is suitable for different return missions and has good adaptability and high expansibility.

Biological safety in the context of backward planetary protection and Mars Sample Return: conclusions from the Sterilization Working Group

AbstractThe National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA) are studying how samples might be brought back to Earth from Mars safely. Backward planetary protection is key in this complex endeavour, as it is required to prevent potential adverse effects from returning materials to Earth's biosphere. As the question of whether or not life exists on Mars today or whether it ever did in the past is still unanswered, the effort to return samples from Mars is expected to be categorized as a ‘Restricted Earth Return’ mission, for which NASA policy requires the containment of any unsterilized material returned to Earth. NASA is investigating several solutions to contain Mars samples and sterilize any uncontained Martian particles. This effort has significant implications for both NASA's scientific mission, and the Earth's environment; and so special care and vigilance are needed in planning and execution in order to assure acceptance of safety to Earth's biosphere. To generate a technically acceptable sterilization process across a wide array of scientific and other stakeholders, on 30–31 January 2019, 10–11 June 2019 and 19–20 February 2020, NASA informally convened a Sterilization Working Group (SWG) composed of experts from industry, academia and government to assess methods for sterilization and inactivation, to identify future work needed to verify these methods against biological challenges, and to determine their feasibility for implementation on robotic spacecraft in deep space. The goals of the SWG were:(1)Understand what it means to sterilize and/or inactivate Martian materials and how that understanding can be applied to the Mars Sample Return (MSR) mission.(2)Assess methods for sterilization and inactivation, and identify future work needed to verify these methods.(3)Provide an effective plan for communicating with other agencies and the public.This paper provides a summary of the discussions and conclusions of the SWG over these three workshops. It reflects a consensus position based on qualitative discussion of how agencies might approach the problem of sterilization of Mars material. The SWG reached a consensus that sterilization options can be considered on the basis of biology as we know it, and that sterilization modalities that are effective on terrestrial materials and organisms should be part of the MSR planetary protection strategy. Conclusions pointed to several industry standards for sterilization to include heat, chemical, UV radiation and low-heat plasma. Technical trade-offs for each sterilization modality were discussed while simultaneously considering the engineering challenges and limitations for spaceflight. Future work includes more in-depth discussions on technical trade-offs of sterilization modalities, identifying and testing Earth analogue challenge organisms and proteinaceous molecules against chosen modalities, and executing collaborative agreements between NASA and external working group partners to help close data gaps, and to establish strong, scientifically grounded sterilization and inactivation standards for MSR.

Vertical controlled landing on 67P / Churyumov-Gerasimenko

With the increasing interest of small body science due to its important role in the puzzle of the solar system formation, missions to small bodies are studied and developed in preparation for future exploration. Together with the operational experience gained and the general rapid technology development, landers and surface mobility elements enable more and more an enhancement of the scientific mission return by collecting in-situ measurements or samples of the surface. Hence, the descent and landing operations become a vital part in a successful execution of the mission.In this paper, a descent strategy for a vertical landing on small bodies is presented. A controlled descent and landing sequence is proposed as opposed to ballistic descents used in previous small body landers (Ulamec and Biele, 2009). The analysis aims for a generic investigation of the surface accessibility of a small body on the example of the comet 67P/Churyumov-Gerasimenko. A vertical controlled descent trajectory concept is proposed and applied to all surface facets of the downscaled ESA polyhedron shape model (released in 2015 (ESA, 2015)). The trajectories are assessed by their duration of descent, Δv need and their surface accessibility with respect to safety distances to the surface and the canyon walls.The analysis results in Δv need ranges between Δvmin=0.7 m s−1 and Δvmax=3.1 m s−1, the duration of descent between tmin=65 min and tmax=275 min. If a minimum distance of 175 ​m to the canyon surface or walls is considered as safe, 90% of the comet’s surface is accessible with the described implemented strategy.

Lunar Regolith Temperature Variation in the Rümker Region Based on the Real-Time Illumination

Chang’E-5 will be China’s first sample−return mission. The proposed landing site is at the late-Eratosthenian-aged Rümker region of the lunar nearside. During this mission, a driller will be sunk into the lunar regolith to collect samples from depths up to two meters. This mission provides an ideal opportunity to investigate the lunar regolith temperature variation, which is important to the drilling program. This study focuses on the temperature variation of lunar regolith, especially the subsurface temperature. Such temperature information is crucial to both the engineering needs of the drilling program and interpretation of future heat-flow measurements at the lunar landing site. Based on the real-time illumination, and particularly the terrain obscuration, a one-dimensional heat equation was applied to estimate the temperature variation over the whole landing region. Our results confirm that while solar illumination strongly affects the surface temperature, such effect becomes weak at increasing depths. The skin depth of diurnal temperature variations is restricted to the uppermost ~5 cm, and the temperature of regolith deeper than ~0.6 m is controlled by the interior heat flow. At such a depth, China’s future lunar exploration is adequate to measure the inner heat flow, considering the drilling depth will be close to 2 m.

Jonathan Chao and “Return Mission”: The Case of the Calvinist Revival in China

Abstract Studies on mission and migration have often focused on the propagation of Christianity from a home context to a foreign context. This is true of studies of Christian mission by Catholics and Protestants, but also true in the growing discussion of “reverse mission” whereby diasporic African and Korean missionaries evangelize the “heathen” lands of Europe and North America. This article proposes the alternative term “return mission” in which Christians from the diaspora return to evangelize the lands of their ancestral origins. It uses the case study of Jonathan Chao (Zhao Tian’en 趙天恩), a return missionary who traveled in and out of China from 1978 until near his death in 2004 and is considered an instrumental figure in the revival of Calvinism in China. This article suggests that “return mission” provides a new means to understand the subjects of mission and migration, and raises new challenges to questions about paternalism and independency.

Reentry Capsule for Sample Return from Asteroids in the Planetary Exploration Missions

For carrying sample from the bodies of interplanetary space, a wide range of knowledge of reentry technology is needed. HAYABUSA(MUSES-C) was an asteroid explorer returned to the earth after the 7 years of voyage, and its capsule reenters into the Earth’s atmosphere, which was a good example of reentry technology implemented to the flight vehicle. It performed a safe reentry flight and recovery. For the design of the capsule, many considerations were made due to its higher entry velocity and higher aerodynamic heating than those of normal reentry from the low earth orbit. Taking into account the required functions throughout the orbital flight, reentry flight, and descent/recovery phase, the capsule was deigned, tested, manufactured and flight demonstrated finally. The paper presents the concept of the design and qualification approach of the small space capsule of the asteroid sample and return mission. And presented are how the reentry flight was performed and a brief overview of the post flight analysis primarily for these design validation purposes and for the better understanding of the flight results.

No‐guess indirect optimization of asteroid mission using electric propulsion

SummaryThis paper researches the optimal opportunities and trajectories for an asteroid‐Earth return mission and compares different options in terms of time length and reentry velocity. High specific impulse and steering capabilities of solar electric propulsion are exploited to perform deep space maneuvers. An indirect method based on the theory of optimal control is applied to find the trajectory that maximizes the final mass. The boundary value problem that arises from the application of the optimal control theory is solved by means of a shooting procedure based on Newton's method. In particular, the best opportunities to reach the Earth are first analyzed by searching a time‐free transfer that intercepts the Earth's orbit at the most favorable point; suitable launch windows are then determined. This technique shows significant benefit to define the initial solution that is required to start the optimization process so that no initial guess of adjoints is required for the optimization. Mission opportunities returning from asteroid Bennu (101955) are presented.

Mission to Mars: Adaptive Identifier for the Solution of Inverse Optical Metrology Tasks

A human mission to Mars requires the solution of many problems that mainly linked to the safety of life, the reliable operational control of drinking water as well as health care. The availability of liquid fuels is also an important issue since the existing tools cannot fully provide the required liquid fuels quantities for the mission return journey. This paper presents the development of new methods and technology for reliable, operational, and with high availability chemical analysis of liquid solutions of various types. This technology is based on the employment of optical sensors (such as the multi-channel spectrophotometers or spectroellipsometers and microwave radiometers) and the development of a database of spectral images for typical liquid solutions that could be the objects of life on Mars. This database exploits the adaptive recognition of optical images of liquids using specific algorithms that are based on spectral analysis, cluster analysis and methods for solving the inverse optical metrology tasks.

Editorial: International ESA Conference on Guidance, Navigation &amp; Control Systems 2014

miniaturisation efforts as well as techniques for advanced estimation, control and verification. Two very high accuracy missions, namely Euclid and GOES-R, are presented in the first two papers. They provide a good illustration of the overall engineering process, which includes mission objectives flow down to Attitude and Orbit Control System (AOCS) requirements, sensors and actuators selection, control design analysis and performance verification. Euclid is a medium-class mission of the ESA Cosmic Vision 2015–2025 plan. Operating around the L2 Lagrangian point of the Sun–Earth system, it will seek to understand the origin of the universe’s accelerating expansion. GOES-R will be the first of the next-generation geostationary weather satellites, managed by NOAA and NASA. Both missions have unprecedented pointing performance and image quality requirements, which require innovative pointing architecture and implementation. Planetary exploration missions are also highly inspirational and demanding in terms of GNC-enabling techniques. Mars exploration is addressed in three papers: firstly, with the Exomars 2016 mission and the Orbiter GNC implementing aerobraking strategies; secondly, with the in-flight experience gained from the Entry, Descent and Landing of the Mars Science Laboratory; and lastly with vision-based autonomous Rendezvous and Capture technologies under development for future Mars sample and return missions. Lunar exploration is then covered by a paper on autonomous landing with hazard detection and avoidance techniques. New challenges related to space debris mitigation are presented in two papers on active debris removal. The first is a general survey of the GNC-related needs, followed by a student paper on the combined control of a chaser and its robotic arm. This special issue of the CEAS Space Journal has been prepared from a selection of the most interesting presentations delivered throughout the different sessions of the 9th International ESA Conference on Guidance, Navigation & Control Systems. Every three years, this conference offers a unique window into the most recent experiences and innovations of the international GNC community, as well as a detailed insight into the demanding requirements of future missions. The latest conference, held in June 2014 in Porto, was attended by more than 250 GNC engineers, managers and decision makers from around the globe. A broad range of GNC-related topics was covered by presentations of the highest calibre. Thanks to the authors who accepted to submit their papers to the CEAS Space Journal, and thanks to the reviewers, we are happy to provide a representative and up-to-date survey covering challenging missions and associated GNC developments, new sensors including