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Space-age technology makes it possible to travel faster than the speed of sound from one continent to another one or even to make suborbital flight as a space tourism. The existing technology challenge is to bring this innovative way of travel without damaging the environment to ensure human safety and to preserve environment balance. The sonic boom issue is one of the concerns when flying faster than sound. The issue must be taking into account at the stage of developing environmentally friendly high-speed vehicle. The next generation supersonic transport is fundamentally different from subsonic medium- and long-range aircraft in a breakthrough feature: it ensures a long-term supersonic cruise flight in the range of Mach numbers 1.6–1.8. For a successful implementation of the civil supersonic project at a new stage of technology development, it is necessary to solve a number of scientific and technical problems. In the present paper some of them are under discussion. In particular, the addressed issues are as follows: how to achieve a high level of aerodynamic efficiency at supersonic cruise along with low sonic boom; how to fit into low noise requirements at take-off and landing modes of supersonic aircraft with a moderate-bypass-ratio engine; how to implement a wing with high load factor and fuselage with long nose part to fit into required airframe structural stiffness, etc. Also, new technology approaches in multidisciplinary optimization task to achieve aircraft design goals of low drag, low boom and low noise characteristics are discussed. A few examples of optimal supersonic aircraft configurations along with passenger cabin are given. The paper was presented at the X-th IAA Symposium "Space Flight Safety" in St.-Petersburg on June 2023. • Preliminary aerodynamic design,. • Advanced supersonic transport,. • Sonic boom,. • Multifactor optimization,. • Aerodynamic configuration. [ABSTRACT FROM AUTHOR]

A comprehensive approach to creating a control system for the shape of the radio-reflecting surface of a large-size space reflector is considered. Large-aperture space antennas are used for satellite communications and space exploration. The design of these structures is one of the most promising areas. Ensuring the specified characteristics of the reflector is directly related to maintaining the specified shape of the radio-reflective netting. Developing a control system for the shape of the active antenna surface is an urgent task. Optimizing this process makes it possible to accomplish the mission during the operational period effectively. The paper evaluates the effects of perturbations on a large-scale structure operating in outer space. A method for adjusting the geometry of the frontal network is proposed. This allows for improved communication between spacecraft and ground stations, which is very important for the safety of space flights. The conductive parts of the reflector are considered to transmit energy and control signals to the actuators. The application results of various control algorithms of the executive device making it possible to correct the netting considering the minimization of energy costs and oscillations of the structure are shown. According to the simulation results, the optimal algorithm of the target criteria hierarchy showed greater stability in terms of convergence in the presence of measurement noise and disturbances, which allows it to be applied in real time. This algorithm is supposed to be used in the future when creating a prototype of the system for controlling the shape of the radio-reflective surface of a large-size space reflector using its current-conducting structural parts. • The design of a system for setting up and maintaining a radio-reflective network fabric has been developed. • Algorithms are developed to minimize energy when setting up a radio-reflective mesh. • The optimal algorithm of the control allows solving the problem in real time. • The method for transmitting energy and control signals through the use of conductive structural parts of the reflector is proposed. [ABSTRACT FROM AUTHOR]

Virtual reality (VR) and augmented reality (AR) are rapidly developing technologies that may have important healthcare-related applications, including the possible evaluation of the health and performance of astronauts. Advances in the fields of VR/AR and space exploration have independently progressed; however, over the last decade synergies and overlapping applications have emerged between spaceflight and extended reality. This paper is intended to be a resource to update the medical community on the current and future integration of VR and AR into space exploration, particularly as this integration relates to astronaut health. We highlight how these technologies are used in terrestrial healthcare with specific attention to visual function. Furthermore, we elaborate on emerging VR applications being developed for future spaceflight. The paper discusses the current state of the art, such as the Apple Vision Pro headset, and outlines key challenges like mass and volume constraints, power limitations, and the heightened cognitive and physical demands of space travel. It also addresses the potential of VR/AR technologies to mitigate these issues through efficiency, stress reduction, and exercise motivation. Finally, we emphasize the benefits that these technologies provide to overcome possible barriers to long duration spaceflight and manned exploration missions, including spaceflight associated neuro-ocular syndrome (SANS). • Virtual reality (VR) and augmented reality (AR) are rapidly developing technologies that may have important healthcare-related applications, including the possible evaluation of the health and performance of astronauts. • This paper is intended to be a resource to update the medical community on the current and future integration of VR and AR into space exploration, particularly as this integration relates to astronaut health. • We highlight how these technologies are used in terrestrial healthcare with specific attention to visual function. Furthermore, we elaborate on emerging VR applications being developed for future spaceflight. [ABSTRACT FROM AUTHOR]

All current rehydratable food and drink items prepared for U.S. astronauts on missions to the International Space Station (ISS) must be compatible with the station's potable water dispenser, called the rehydration station. This highly validated system ensures that water is compartmentalized and safely transferred to custom-made food and beverage pouches to prevent free-floating food particles and water in microgravity. However, the food and beverages packaged in these single-purpose pouches require complex, time-consuming, and costly procedures before flight, which is not feasible for future commercial space stations seeking more affordable life-support systems. Furthermore, even though a vast number of rehydratable food and beverage items available at supermarkets have appropriate nutritional content and shelf life for spaceflight, their incompatible consumer packaging renders them unusable by astronauts. In this paper, we present a low-cost solution that draws on NASA technology to adapt these commercially developed food and drink items for spaceflight and makes them compatible with the water dispensing unit and consumption in a microgravity environment. The 3D-printed adapter is based on the NASA septum adapter with the addition of a piercing end and one-way barb that stabilizes the adapter inside the food pouch and ensures it is not released due to the force generated by the water when it is dispensed. The dimensions of the adapter are 20.00 (L) x 12.50 (W) x 37.24 (H) mm and the mass is approximately 1.5 g. The design is compatible with at least three types of packaging commonly used for commercially available rehydratable foods: kraft paper and polymer laminate (KP), polymer aluminum laminate (PA), and compostable polymer laminate (CP). Based on these three packages, we present a table of commercial items that could be available to astronauts if the adapter were to be used. To validate the adapter's use in the space environment, we also present data on the structural properties against loads experienced during launch and re-entry, as well as two functionality tests to determine piercing and rehydration effectiveness. The results show that the prototype of the adapter meets structural specifications for spaceflight and can effectively pierce KP and PA materials with minimal tear propagation. The rehydration test with KP showed that the adapter can effectively rehydrate a typical dehydrated food package. In summary, the adapter is an effective method to increase menu diversity while simultaneously eliminating costs associated with space food preparation and re-packaging. • A new proof-of-concept adapter for food and beverage rehydration in space was demonstrated. • Adapters can be made compatible with U.S. galley equipment on the ISS. • Enabling commercial food on the ISS could significantly reduce costs of human spaceflight. [ABSTRACT FROM AUTHOR]

The Moon has returned into the focus of human endeavors regarding human spaceflight, e.g., with NASA's Artemis program, ESA's Moon Village, and the Russian/Chinese International Lunar Research Station. In difference to the pathfinding missions of the Apollo -era, the goal for these future missions is to stay on the lunar surface for longer durations and inhabit the lunar environment (near-)permanently. This requires a different approach to be affordable, i.e., instead of resupply as mostly used on e.g., the International Space Station, resource management has to include recycling and in-situ utilization. The former especially calls for the application of so-called BLSS to allow providing essential life-support services to the crew without prohibitive resource consumption, which is economically not feasible to achieve with resupplies. Bio-regenerative-life-support systems have been researched for decades, yet the system complexity, technology advancements, and singular aspects as e.g., plant biology require more research, especially if combined as in a greenhouse. For instance, the understanding of how a microbiome develops in a closed environment and what implications the microbiome has on plant growth is still insufficient. Within the EDEN project, the German Aerospace Center built a lunar analogue greenhouse and operated it at the Neumayer-III research station in Antarctica for four years, testing the technology – which was not space hardware – and operations. Derived from this experience the next step in the project is to design and subsequently operate a ground test demonstrator for a lunar greenhouse, as close as possible to the actual space hardware and operations. This paper explains the current design and trade-offs that led to it. Furthermore, the concept of operations is shown to illustrate the demonstrator's utility for researching bioregenerative-life-support. Overall, the system presented is feasible and useful to close the gaps, currently still existing in this field of research, and thus a mission enabler for future long-duration human space exploration missions. • Design of an integrated greenhouse module test demonstrator. • Extensive science program definition. • Mission scenario definition for lunar greenhouse. • Discussion of benefits and open issues. [ABSTRACT FROM AUTHOR]

Lunar sun-synchronous roving is an affordable and promising manner of acquiring continuous power supply and warmth in robotic polar exploration. Sun-synchronous route planning is challenging to meet the spatiotemporal constraints of lunar topography and time-varying illumination. Moreover, in pursuit of spaceflight feasibility and safety, the safety-optimal planning method adapting to spatiotemporal maps remains to be addressed. This paper takes the first step to investigate this issue, in which the distribution of roving speed is considered a critical factor. Three-dimensional lunar spatiotemporal maps are constructed based on topography and illumination analysis. A spatiotemporal planning algorithm named MSST-A* is proposed, which takes a multi-speed node expansion mechanism, thus supporting speed distribution optimization. Afterward, route evaluation functions involving motion, energy, and integrated risk, together with the optimal heuristic function, are designed for safety-optimal planning. Two comparative tests are conducted, and results indicate that the proposed approach is practical and superior in terms of motion safety and energy reliability. Besides, an integrated-risk-minimal route circumnavigating the Shackleton Crater at the south pole in three lunar days is solved, demonstrating the existence of long-term lunar sun-synchronous routes with good engineering significance. • The paper is innovative in the following bullet points: • Safety-optimal lunar sun-synchronous route planning is firstly studied. • MSST-A* for optimizing the spatiotemporal distribution of speed is raised. • Polar sun-synchronous circumnavigating routes of fine safety are solved. • The existence of the sun-synchronous route of engineering reliability is proved. [ABSTRACT FROM AUTHOR]

Collisions with micrometeoroids and space debris can perforate spacecraft shields and hulls; in-situ repair or substitution of the damaged elements is currently considered a complex task, in particular the case of crewed modules with pressurized elements. In this context, cold-welding can overcome the current technological difficulties allowing fast and safe repairing procedures. To date, it has been shown that similar metallic materials can fuse or weld at ambient temperatures provided that there are sufficiently high contact forces. In the space environment this fusion is aided by the fact that the joint surfaces do not re-oxide after wear and, as a consequence, atomic diffusion of the metal occurs at lower contact forces. It has also been demonstrated that, even under terrestrial conditions, the action of a low fretting load can nearly double this adhesion force. In this paper, the suggested utilization of cold-welding phenomenon for spacecraft hull repair is described, as well as a verification road map to demonstrate its feasibility. It is proposed to develop an experimental test rig to apply custom repair patches of different materials to pre-damaged metallic structures and monitor the performance the adhered joint in low orbit and during re-entry. The test samples will include simple plates, Whipple shields, and sandwich panels that have been subjected to hypervelocity impacts. In the first phase, the cold-welding phenomena will be investigated in ground laboratories and validated in a vacuum chamber; afterwards, it is proposed to repeat the experiment in microgravity conditions, during a sounding rocket flight. Results will include an assessment of the contact forces necessary to apply the repair patch and an evaluation of the structural properties of the refurbished systems. • Cold welding for spacecraft repair following a hypervelocity impact by space debris. • In-situ repair from inside the spacecraft is preferable. • Test apparatus to apply custom repair patches. • Experimental setup integration as a sounding rocket payload. • Hypervelocity impacts tests are designed to have realistic samples. [ABSTRACT FROM AUTHOR]

Exploring farther into our solar system for planetary exploration will require the human crews to reside in their space transfer habitats for a long period of time. These explorers will also face isolation, owing to the sheer physical distance from the Earth, which may eventually affect their health and well-being. Furthermore, looking at a trip to Mars, astronauts may need to wait for as long as 40 min before receiving updated round communications from Earth, due to the time it takes for the signal to travel the separation distance at the speed of light. Thus, when it comes to long-duration crewed space missions, communication and the feeling of connection with their loved ones—friends and family—on Earth is crucial for the astronauts' well-being. In this context, exploring a new communication approach for long-duration spaceflight seems necessary for our missions to Mars. This paper attempts to introduce a new way of decoupled communication that enables astronauts to connect with their feelings towards their loved ones on Earth via embedded interactions, focusing on the idea of "qualitative contact". The idea of qualitative contact was inspired by one of our previous studies on the concept of "qualitative interface" in relation to HCI (Human-Computer Interaction), then extended to our case study for human-object interactions. Much of how we construct meaning in the real world tends to be qualitative rather than quantitative. Yet quantification has become a default method for displaying, presenting and communicating information. In this paper, we explore beyond the idea of ordinary distance communication and information exchange during deep space exploration in particular during long-duration interplanetary spaceflight. We introduce how human explorers in a space transfer habitat can qualitatively contact their loved ones on Earth during their long-duration space missions. We discuss our design processes, which includes the study of human-centredness, communication barriers, the ideation process, and prototype development with a boundary-object based demonstration. We believe that our communication method or tool can stimulate ideas for space habitat designs beyond today's technological solutions for long-duration and long-distance space missions. By advancing the astronauts' physiological and psychological well-being, human explorers could venture to expand our civilisation deeper into the solar system. What are the ways to make astronauts feel connected with their family and friends back on Earth during their long-duration space missions? Here we share the idea of qualitative contact through a device we call Martian Delight—a device intended to advance the astronauts' well-being. • Decoupled communication methods could be helpful for improving astronauts' well-being during deep space missions. • Reward systems could encourage astronauts' well-being and a healthy lifestyle during long duration space missions. • Focusing on human-interaction is one of the key factors of advancing habitat design for deep space explorations. [ABSTRACT FROM AUTHOR]

Continuous missions to Low-Earth Orbit, Moon and even Mars missions are the prospect for the coming decades of especially human spaceflight. The actors in these missions are commercial and institutional, public and private. The bandwidth of planned missions is wide, ranging from scientific exploration to commercial exploitation. In-situ resource utilization is planned to support such missions and thus reduce the amount of effort needed for transportation of goods to mission regions, e.g. by supplying water or fuel on the lunar or Martian surface. In the past decades the concept of sustainable development and sustainability has been evolved and became more and more relevant for many aspects of human life and society. These terms have also migrated into more specialized fields such as spaceflight. This paper systematically reviews the concepts of sustainable development and sustainability which have been formulated in a spaceflight context implicitly and explicitly. For this purpose, four perspectives are defined which originate from either Earth or space and alternate with the addressed object between Earth and space as well. It is explained and discussed how these concepts manifest in a spaceflight context, how they evolved over time and which implications result from the respective point of view. Subsequently, the formulation of space in-situ sustainable development is coined and an outlook is given how to further evolve this centric idea to enable a comprehensive evaluation of mission scenarios and roadmaps with regard to their sustainability. • Review of existing concepts concerning sustainability in spaceflight. • Relating these concepts to the original formulation for sustainability. • Pointing out gaps in existing concepts, e.g. disregard of social or environmental aspects. • Proposal of a new, comprehensive definition for space-in-situ-sustainable development. [ABSTRACT FROM AUTHOR]

Space debris creates a serious problem for Space flights safety in Low Earth Orbits. In this paper, the results of high velocity Space debris fragment interaction with thin metallic shields are presented. The formulas for determining critical thickness of the target preventing from penetration being functions of impactor mass, speed and material properties of both impactor and target are developed. The developed simplified models are supported by results of physical and numerical experiments. • Formula for calculating ballistic limit thickness of the shield is obtained. • Formula for calculating ballistic limit velocity is presented. • New criterion for different scenarios of the high-speed collision is introduced. • For low density impactors the ballistic limit curve is practically monotonous. [ABSTRACT FROM AUTHOR]

Space operations in the United States has required the skills of aerospace medicine specialists since the before the inception of human spaceflight in 1958. The literature extensively covers physiology, clinical science, and conjectures on the nature and future of space medicine. The goals of this project were to examine the evolution of the operational spaceflight surgeon, define the role today, and explore the future of operational space medicine. The data gathered for this project were obtained from several sources including personal interviews with actively serving NASA personnel, a literature review identified by searches of MEDLINE, Current Contents, PubMed, Google Scholar, internal NASA records and databases, and references from relevant articles. Only articles published in English between 1961 and 2019 were included. Finally, to provide a primary account to compliment the findings from above eight oral histories were examined from leaders in this field. This paper reviews the evolution of operational spaceflight medicine from the NASA perspective, offers a modern definition by those who practice it on a daily basis and explores its future development as a profession. While this work is inherently limited as defined by the experiences of select individuals; the 336 combined years-of-service of the sources, personal interviews, and command perspectives of the authors attempt to lay a foundation for such a definition. Understanding and appreciating this history is key to the successful future development of operational spaceflight medicine as a specialty, and by extension to manned space exploration as a whole. • History of the operational flight surgeon from the NASA perspective. • Period - 1958 through the current time period. • The knowledge shared here has been collected from the historical record, first hand accounts. [ABSTRACT FROM AUTHOR]

The importance of interdisciplinary approaches through collaborative mindset, cross-field knowledge, and co-creative team actions is integral for continuing space exploration success as evidenced by past and ongoing terrestrial space habitat analog missions and extraordinary International Space Station (ISS) achievements. This paper presents the third annual iterative outcomes of an innovative university-based space program using Project Based Learning (PBL) methodology in creating design ideas for astronaut health support and wellbeing during a long duration mission (LDM) for a future inhabited lunar moon base or Mars Mission astronaut transit. University faculties including Built Environment, Industrial Design, Engineering, Science, and Health, at Western Sydney University Australia and supported by University of Houston USA are brought together to develop a new understanding of discipline capabilities with the prospect to co-creatively provide new opportunities and inspiration for teamwork across fields. This is of key interest to employers of new graduates in space or innovation-based industries where human factors and designing for high quality human-centered outcomes supports career resilience through currency, agility, and focus. The altruistic nature of interactions that make the ISS a success on multiple levels across cultural, scientific and humanitarian foundations provide the template for cross-disciplinary inspiration, that leverage synergies, and shared goals unattainable by single fields alone. It is not common for disciplines to work so closely together though industry has an expectation for this knowledge. Previously teams of three (2018); five (2019), and now ten undergraduates in 2020 represent team formation. Student numbers across the design for space theme have grown annually from fifteen, to twenty-five, to forty students in 2020. Now opportunities to respond to the complexities of the project in more detail are presented in addressing the overarching research domains in spatial design, human factors and design for health for LDMs. Team supervisory academic staff grew from 1-to-3 and provided further team guidance and discipline specialisations to inform three iterative project phases across the twelve activity weeks for four teams focusing on human spaceflight, exercise, related design performance and materials, and selected UNSDGs principles. The paper outlines the methodological approach, assessment methods, acculturation to working in teams and immersion in space knowledge for newcomers, and a review of forty collaborative outcomes all conducted by migrating Online during the COVID19 pandemic of 2020 by necessity. Periodic project collaborations with sports and health science, engineering, health informatics, space architects, a former astronaut, a representative from NASA Johnson Space Center (JSC) Flight Control, and industrial design academics (project host discipline and non-traditional space area) provided an environment for discussion, development, and co-creative processes that have led to new discoveries and stimuli for new collaboration, international understanding and advancing humankind in space and on earth. • University space curriculum in design for Astronaut health and wellbeing • Space Habitat Design • Interdisciplinary Project Based Learning • Astronaut Health on Long Duration Missions • Space Architecture [ABSTRACT FROM AUTHOR]

The paper reports the results of the Cardiovector space experiment, performed onboard the International Space Station (ISS) in 2014–2017 with the participation of 12 cosmonauts - members of the long term space flights. Each cosmonaut was examined in the following order: twice before launch; every month during the flight and twice after landing. The following physiological signals were registered: electrocardiogram, ballistocardiogram along three mutually transverse axes and three rotation axes, impedance cardiogram, seismocardiogram and pneumotachogram. The experimental protocol consisted of 5 min of rest, 3 min of fixed breathing with 5 and 10 s cycles, and tests with maximal inspiratory and expiratory breath-holds. The paper shows dynamics of BCG amplitude changes along the body longitudinal axis (Y). The investigation showed that microgravity forms a new hemodynamic pattern characterized by increased, compared to that on Earth, filling of the pulmonary circulation at rest, particularly during the first month during mission, and elevation of the left ventricle activity in this period. This fact, probably, points to a gradual unloading of the pulmonary circulation. • Activity of the right and left ventricle of the heart at different stages of a long duration space flight. • Spatial pulse-induced body movements simultaneously along six axes of ballistocardiogram. • More intensive activity of the left ventricle on the first month of space mission. • Increased filling of the pulmonary circulation for the cosmonauts. [ABSTRACT FROM AUTHOR]

The Station Explorer for X-ray Timing and Navigation Technology (SEXTANT) mission is a technology demonstration enhancement to the Neutron Star Interior Composition Explorer (NICER) mission, a NASA Astrophysics Explorer Mission of Opportunity to the International Space Station (ISS) that was launched in June of 2017. The NICER instrument is a precision pointing X-ray telescope that tags pulsar sourced photon arrivals which the SEXTANT mission uses to perform autonomous on-board X-ray Pulsar Navigation (XNAV). By comparing the detected time of arrival of X-ray photons to a reference of expected pulsar timing models, one can infer a range and range rate measurement based on light time delay. Since the celestial source provides both timing and directional information, this technology could provide a GPS like navigation capability available throughout the Solar System and beyond. Applications that XNAV can support include outer planet and interstellar missions, manned missions, libration orbit missions, and current infrastructure such as the Deep Space Network (DSN). The SEXTANT team successfully completed a first demonstration of in-space and autonomous XNAV in November 2017. NICER and SEXTANT have separate teams, with NICER being the primary team with different science objectives. Operational modes for both missions must have concurrent and independent components as well as an integrated ground system. This paper describes the operational infrastructure and successful implementation of the SEXTANT demonstration. This paper first details the infrastructure implemented, the concept of operations, and finally the operations for the SEXTANT demonstration and lessons learned. • X-ray pulsar navigation: Use X-ray photons from stars to maintain orbit determination. • NASA SEXTANT: First demonstration of on-board, real-time X-ray pulsar navigation. • SEXTANT is part of the NASA International Space Station NICER X-ray telescope. • SEXTANT operations implement tech demo with separate science/spaceflight operations. [ABSTRACT FROM AUTHOR]

The paper introduces a new method for ground-reaction forces (GRF) analysis for the evaluation of cosmonaut locomotor functions stability after a long-duration spaceflight (LDSF). The method is based on the analysis of GRF profiles obtained before and after LDSF by standard БД-2 treadmill reaction force data readings. Following probabilistic indicators were introduced: distributions of step and step-phase duration probabilities, their extremums, standard deviations and inverse coefficients of variety; step structure variability; the non-stationarity index for step durations arrays; GRF pattern, its width and maximum. Every indicator of one cosmonaut pilot study has changed drastically after LDSF. The new statistics provided appeared to be promising indicators of locomotor function state. A further trial of the new method may provide new knowledge of human movement strategies alterations after LDSF and may establish it as a standard analytical procedure for personalized flight assistance after its reliability verification. • New standard tests are needed for cosmonaut locomotor function evaluation. • The new GRF analysis method for standard ISS equipment was introduced. • The new GRF analysis showed drastic changes in one cosmonaut parameters. • Step duration stability, step pattern, IVC and others changed after spaceflight. • The new indicators are promising but more test subjects are needed. [ABSTRACT FROM AUTHOR]

Major surgical events/incidents onboard are rare but can be catastrophic to any mission. National Aeronautics and Space Administration (NASA) uses the Integrated Medical Model (IMM) to develop an integrated, quantified, evidence-based decision support tool useful for crew health and mission planners to assess risk and design medical systems. In 2017, the IMM of the NASA Human Research Program included a list of 100 medical conditions that could be anticipated during space flight. Of those conditions, 27 are expected to need surgical treatment. Consequently, there has been a continuing interest in surgical capabilities for exploration space flight. The surgical system capabilities aboard all space stations and analogue flights have been designed and implemented with an emphasis on stabilisation, medical evacuation, and ATLS capabilities. However, with future missions to the Moon and Mars, evacuation is not a possibility and astronauts will need to troubleshoot, adapt, and self-administer complex surgical care autonomously. This narrative review aims to examine the published work on surgical care in space, discuss the inherent challenges, and identify scope for future studies. The review evaluates and analyses results from several landmark experiments covering important technical aspects such as basic surgical skills, laparoscopic surgery, robotic surgery, and tele surgery. Relevant studies for the review were identified from the MEDLINE, PubMed, and EMBASE databases. Eligible studies were published between 1960 and June 2021 and were identified using the terms "space surgery", "microgravity", "zero gravity", "weightlessness", "parabolic flight", "neutral buoyancy", and "spaceflight". Only articles in English were selected and references cited in the selected publications were followed up and included where appropriate. Documents available in the public domain and/or archives of National Space agencies were also included. The search yielded a total of 86 hits including review articles, commentaries, studies, meeting summaries and technical reports submitted to National Space agencies. Results were then filtered for eligible papers relevant to this narrative review. Challenges on a long-duration mission will be unique, unlike anything we have faced so far in the last 60 years of space travel. Despite the progress in space surgery in the last 40 years, there are several challenges to achieving a fully functional surgical care system on any mission outside Low Earth Orbit. The microgravity environment presents unique challenges related to altered physiology as well as mechanics and techniques pertinent to surgical care. Some of the challenges include but are not limited to crew selection, role of prophylactic surgery, adaptation to zero gravity, lack of ground support, training and maintenance of surgical skills and limitation of weight and volume for hardware. Ultrasound imaging, 3D printing and AI-based surgical assistance coupled with robotic surgery have shown promise, but their real efficacy and functionality remains to be tested. • Inability to repatriate has highlighted need for autonomous surgical care. • Adaptation to weightlessness for the patient and surgeon is important to consider. • Crew selection, training and maintenance of skills will be critical. • Conservative and minimal access management of surgical conditions is predicted. • Ultrasound and 3D printing will play an important role in surgical care. [ABSTRACT FROM AUTHOR]

Space agencies use terrestrial-based analog missions to reduce risk and cost of spaceflight operations. This paper explains how research simulations differ from more traditional spaceflight analogs, and describes medical mishaps that may occur. Suggested paths to improved safety standards will better prepare health and safety officers to address healthcare gaps. • Analog space missions use terrestrial environments to simulate aspects of real space. • They vary significantly in fidelity, funding, resources, and organization. • A safety focused risk assessment should be conducted regardless of analog type. • The roles and responsibilities of health and safety officers are many and diverse. • Reporting significant adverse events is encouraged. [ABSTRACT FROM AUTHOR]

This paper introduces a new, preliminary physical ergonomics model for spacecraft cabin and cockpit architecture and for control systems layout conceptualization. The research was executed during a year-long collaboration between the Florida Institute of Technology's Human Spaceflight Laboratory and Embry-Riddle Aeronautical University's Spacesuit Utilization of Innovative Technology Laboratory. It focused on physical ergonomics using an adjustable intravehicular activity Terra Spacesuit manufactured by Final Frontier Design (FFD). The main goal of this laboratory research was to generate an FFD spacesuit specific reference model of reach envelope. The model provides concrete numerical data about potential spaceflight participants' or astronauts' upper body motion, which can be used to improve spacecraft interior design. The reach envelope was mapped using an IR motion tracking system in unsuited, suited unpressurized, and suited pressurized configurations. The resulting model is presented as a geometric area accessible to all test subjects participating in this research. Although this experimental model is based on training spacesuit hardware and operated under lower (1.5 psid) than usual (3.5 psid) operating pressure, it demonstrates the physical ergonomic limitations of wearing an Intra Vehicular Activity pressurized suit. This model further helps spacecraft cabin, flight deck or cockpit architects to identify the optimum internal layout of the vehicle, placement of the control and display components. Control function activation during specific phases of the spaceflight may require either unpressurized or pressurized spacesuit operations. The accessibility of the control input systems is the primary factor in their placement inside the cockpit. More importantly, the vehicle controls, system input devices, and displays should be not only within reach, but also within an executable/operational position and configuration, or work envelope. • Spacecrafts' interiors are driven by physical ergonomics of IVA spacesuits. • IVA size-adjustable spacesuit upper body reach baseline model has been created. • Model represents IVA spacesuit pressure 1.5psid and 160–188 cm tall occupants. • Model is directly applicable for a spacecraft cabin or cockpit concept engineering. • Recommendations for human spaceflight spacecraft controls placement are provided. [ABSTRACT FROM AUTHOR]

This paper presents Rocket Experiment (REX) that was part of a dual-payload rocket campaign for NASA's sounding rocket Black Brant IX with water recovery technology. This mission was a suborbital sounding rocket flight that was launched and recovered on April 4, 2018 and targeted the Vela supernova remnant. The purpose of REX was to classify the Technology Readiness Level of onboard devices designed for space applications. The devices were two wide-field X-ray telescopes consisting of a combination of Lobster-Eye (LE) optics with an uncooled Timepix detector (256 px × 256 px @ 55 μm), and additional sensors. The first telescope uses a two-dimensional combination of LE modules with a focal length of 1 m and a Field of View (FOV) of 1.0 ° × 1.2 ° and operates in the energy range of 3 – 60 keV. The second telescope was a one-dimensional LE with a focal length of 243 mm and a FOV of 2.7 ° × 8.0 ° for the energy range 3 – 40 keV. The X-ray telescopes were supplemented by a camera in the visible spectrum with 1.280 px × 1,024 px resolution, which was used to obtain images of the observed sources and to verify the resulting pointing of the rocket carrier. Other devices also include infrared array sensors and inertial measurement units tested for future small satellite missions. The data handler and communication system were built using the Robot Operating System, and both the system and the electronics were deployed and operated in-flight. The hardware was successfully recovered after the launch and the data were extracted. • Successful rocket experiment in cooperation with universities and companies. • Technology Readiness Level verification of devices on suborbital rocket. • Sounding rocket experiment driven by the Robot Operating System. • Lobster-Eye X-ray optic with Timepix detector survived the suborbital mission without damage. • Off-the-shelf MEMS sensor was able to survive rocket launch, mission and landing. [ABSTRACT FROM AUTHOR]

Analog environments for simulating aspects of spaceflight are being utilized for studying the psychological effects of the projected journey to Mars. In 2016, a series of three analog missions concluded at the Hawaii Space Exploration Analog and Simulation (HI-SEAS) facility. Three crews, each with six volunteers per mission, completed consecutive missions of increasing duration, simulating the isolation and confinement of a Mars exploration mission. The durations of the analog missions were 4 months, 8 months, and 12 months, respectively. In this paper, former crew members of these three missions compare how each crew organized their schedules with regard to work routines and social activities. We outline group-living habits that evolved similarly in the independent crews, and we discuss where social norms differed, leading to idiosyncratic policies for group-living during each mission. This information may serve as a reference to mission planners of both simulated and actual human spaceflight missions and also offers insights for psychology researchers that could motivate future studies of team cohesion and performance. • Three long-duration Mars analog missions conducted at HI-SEAS habitat. • Self-organization and habits developed independently in the autonomous crews. • Crew decision-making was consensus-driven in all crews, with little hierarchy. • Work load of the studied crews was comparable to that of actual spaceflight crews. • The crews' behavior indicates how habits may develop during actual Mars missions. [ABSTRACT FROM AUTHOR]

Abstract A Smart Dust is a femto-spacecraft with an external surface coated with electrochromic material, which exploits the solar radiation pressure to produce a propulsive acceleration. As the optical properties of the electrochromic material change upon application of a suitable electric voltage, its propulsive acceleration may be modulated, within some limits, without the use of any propellant. This paper analyzes the optimal trajectories of a Sun-pointing Smart Dust, which provides a propulsive acceleration aligned with the Sun-spacecraft direction. In particular, the paper describes the relative motion of a Smart Dust with respect to a conventional spacecraft (the Mother Ship) that covers a heliocentric circular orbit of given radius. The Smart Dust is required to vary periodically its angular position with respect to the Mother Ship using an optimal (minimum time) strategy. This problem is addressed using an indirect approach and the optimal control law is obtained in a closed-form solution. The results discussed in this paper ensure interesting improvements over existing models from the recent literature, including the possibility of obtaining a generic phasing angle of the Smart Dust and to take into account an optimal number of on-off switchings of the electrochromic control system. Highlights • The paper analyzes the phasing maneuver of a Smart Dust in a circular heliocentric orbit. • The phasing maneuver is studied by evaluating the optimal (minimum) flight time. • The optimization problem is solved using an indirect approach. • The optimal control law is obtained in an analytical form using a lin-earized dynamics. [ABSTRACT FROM AUTHOR]

Abstract This paper aims to assess the feasibility of an interstellar mission to reach the Alpha Centauri star system and delivering scientific data, using current and near-future technology. The mission baseline uses 100 GW of laser power to accelerate a spacecraft of 2750 kg to 5% the speed of light with light sail technology, resulting in a travel time of about a century. This paper explores several aspects of the mission: Possible locations of the laser infrastructure and different sail materials to achieve the required acceleration are discussed. Deceleration using a magnetic sail in the interstellar medium and in the heliosphere of the target star, taking into account mathematical models from Zubrin [6], Freeman [22] and Gros [21], is studied. Potential orbits in the star system are considered for observation and data collection. Finally, a multi-spacecraft mission architecture is presented, as it would allow for the spacecraft to be launched sequentially, thus exploiting the possibility of continuously operating the laser infrastructure. Highlights • Mission architecture to send multiple spacecrafts to Alpha Centauri star system. • Laser sail acceleration and magnetic sail deceleration. • Performance comparison of different light sail materials, on a spacecraft level. • Dependencies between light sail, laser and mission parameters. • Performance analysis of magnetic sails considering different mathematical models. [ABSTRACT FROM AUTHOR]

Abstract It is inevitable that individuals and groups will experience stress and distress in the harsh and extreme environment of deep space. When these occur, we now have a mission in jeopardy -- not due to hardware failure, but because a psychological breaking point has been reached. It will happen. The question is when. This paper seeks to identify signs of impending breakdowns and suggests strategies for a crew to minimize its impact when it does. This paper begins to create definitions and qualities of breaking points, define the impact on group dynamics, and identify post-breakdown recovery strategies that will be used as a foundation for predictive model development. Highlights • An individual's psychological is vital to the success of the mission itself. • Mission cycle type influences the required skill set for individual success. • Group maturity is as important as the individual's ability to cope with the environment. • An individual's psychological health relative to the group dynamics is key. • Other impacting factors are physical health, culture, grief, and gender relationships. [ABSTRACT FROM AUTHOR]

Abstract Italy, as well as many other countries, has increasing interest in Commercial Space Transportation and in particular, in suborbital flights. A suborbital space transportation system is an opportunity to involve the Italian industry in the development of new technologies, exploit opportunities of microgravity experimentation and pilots/astronauts training, as well as catalyse the national industry. The central position of Italy in the Mediterranean basin, the generically favourable climate condition, the touristic vocation resulting in hospitality at the highest level, pretty much allow year round suborbital operations and unique customer experience. Consequently, Italy appears to be a suitable location to host a Spaceport, even though the density of population has to be factored in as a key aspect, together with a proper environmental assessment. This paper outlines the current Italian approach that, instead of focusing on the development of new Spaceport from scratch, evaluates the capabilities of existing airports and their possible upgrades to achieve the Spaceport license, when a proper regulatory frame is established. Advances in the technical activities that are being conducted to assess various Italian sites of interest are described, including trade off methodologies and ranking criteria. Different aspects are considered, from the availability of civil and military airports, to the identification of the best location between coastline or inland sites but, first of all, in compliance to the safety requirements. Some specific Spaceport infrastructure and operational aspects are described, along with their integration with the already existing ones. These include hangars, propellant storage facilities, ground support equipment, high and low airspace surrounding the airport area, ascent and descent corridors, as well as tracking telemetry station to support specific mission profiles in integrated fashion with the existing airport infrastructure and air traffic. The paper will also describe the approach to the definition of a harmonized cooperative regulatory framework, according to the Aviation Authority, that represents the basis to assess suborbital operations and allows the relevant missions execution. In this activity, basing upon an established Memorandum of Cooperation between FAA, ENAC and the Italian Space Agency, the existing FAA/AST regulatory work frame is considered as reference benchmark and further tailored to the Italian case. Some considerations will also be developed relevant to initial challenges to be faced, by interested stakeholders, in starting commercial spaceflight initiatives as a new ground and emerging business opportunity. Highlights • Spaceport and Ground Segment assessment for future suborbital transportation system. • Market opportunities and benefits for the Italian economy. • Spaceport requirements identification for the Italian case. • Spaceport operations business strategy considerations for the Italian case. [ABSTRACT FROM AUTHOR]

Abstract At present, the moon is still an important and preferred destination for human beings to visit due to the abundant resources and its potential to be the stepping-stone and platform of deep space exploration in the future. The manned lunar exploration has very important and profound meaning for leading technology innovation and manifesting comprehensive power of a country. Mission scale analysis and flight scheme selection are key problems for top-level projection and are still remaining to be researched systematically and deeply. This paper focus on the scale analysis of manned lunar landing mission and the optimal selection of flight schemes. At first, the basic configurations and the overall technical specifications of flight vehicle system were presented based on the investigation of traditional vehicles and developing trend of new vehicles. Afterwards, the fundamental elements of flight scheme were defined and the Mission Architecture Matrix was constructed. Based on Mission Architecture Matrix, the scale evaluation method was demonstrated. Finally, the qualitative selection model based on Analytic Hierarchy Process and Gray comprehensive evaluation method were established, the optimal scheme with economic and technical feasibility was given based on these two models. The validity of all models in this paper was tested and verified by different testing examples. The results show that EOR-LOR architecture is the best flight scheme for a short-period manned lunar exploration mission. To the best of our knowledge, it is the very first time that the concept of Mission Architecture Matrix was proposed. The reverse calculating algorithm based on Mission Architecture Matrix could improve the efficiency of mission scale analysis and the presented comprehensive evaluation model could make the selection of flight scheme more objective. These models and methods in this paper could be technical references for preliminary design of manned lunar landing mission. Highlights • Proposed convenient Mission Matrix for manned lunar mission scale estimation. • Built up a quantitative comprehensive evaluation model for mission architecture. • TRL was considered in the evaluation, reflecting engineering realizability. [ABSTRACT FROM AUTHOR]

Abstract The Space Rider Programme, previously named Pride, is an ESA programme whose objective is to define and develop an affordable reusable European space transportation system to be launched by VEGA-C, to be used as a platform for several types of payload applications. Payloads and related applications strongly drive the definition of Space Rider mission and system, then an analysis of end user's needs has been necessary to adequately feed the design process. This paper reports a survey and an analysis with respect to the following payloads classes: 1- Free-Flyer (Micro-gravity experimentation and Radiation exposure); 2- In-Orbit Demonstrations and Validation for several technologies (Exploration, Orbital infrastructures servicing, Earth observation, Earth science, Telecommunication, Reentry); 3- In-Orbit applications (Earth monitoring and Satellites inspection). In particular, the analysis has been carried out with investigation of the current microgravity platforms and payloads needs, In-Orbit Demonstrations (IOD) flight opportunities status and demand from different stakeholders both on scientific and industrial side. Key assets of the Space Rider platform with respect to payload have been defined and the results of the work has been flow down into the identification of a set of requirements for the Space Rider mission and system focusing on main aspects as operations, mass, power, volume and interfaces. Highlights • The Space Rider Programme objective is to define and develop an affordable reusable European space transportation system. • Payloads and related applications strongly drive the definition of Space Rider mission and system. • An analysis of end user's needs has been necessary to adequately feed the design process. • This paper reports a survey and an analysis with respect to several payloads classes. • The results of the work have been translated in a set of mission and system requirements. [ABSTRACT FROM AUTHOR]

Abstract The influence of the surface shape state upon the performance and function of large spacecraft should be considered in design and analyzed in the extreme space environment. Therefore, in this paper, considering the measurement uncertainties and errors exist in large high-precision spacecraft, an interval surface accuracy evaluation method is proposed based on a non-probabilistic approach. To overcome the limitations of insufficient statistical quantification of uncertain parameters, this paper treats uncertainties as non-probabilistic intervals. The conventional root mean square index is extended to uncertain interval numbers, which can be used to evaluate the surface accuracy with the measurement uncertainties and errors. Moreover, to improve the interval expansion problem, subinterval technology is applied to the uncertainty propagation process for surface accuracy evaluation. As long as the bounds of the uncertainties and errors are known, the interval bound for uncertain surface accuracy can be estimated conveniently by interval analysis. Finally, three engineering examples are separately proposed to evaluate the interval surface accuracy thereby validating the effectiveness and veracity of the proposed method. The result obtained in this paper can be regarded as an interval estimator, offering more detailed evaluations and suggestions for large spacecraft design and analysis than deterministic methods. Highlights • An interval surface accuracy method is proposed based on non-probabilistic approach. • The conventional root mean square is extended into uncertain interval numbers. • To improve interval expansion, the subinterval technique is used in surface accuracy. • The uncertain surface accuracy result is an interval estimator rather than a number. [ABSTRACT FROM AUTHOR]

Abstract This paper investigates the fixed-time attitude tracking control problem for rigid spacecraft based on rotation matrix. Two anti-unwinding control schemes are developed such that the desired attitude can be tracked with bounded convergence time regardless of the initial conditions. The first controller is established on basis of a novel sliding mode surface without considering the external disturbance. In addition, the explicit description of the settling time can be provided under this controller. By revising the sliding mode surface and utilizing an adaptive law, the fixed-time stability can still be achieved under the second controller even in the presence of external disturbance. Theoretical analysis and numerical simulations are presented to demonstrate the validity of the proposed controllers. Highlights • Two attitude tracking controllers are designed for spacecraft. • Rotation matrix is used to construct the controllers. • Controllers in this paper are fixed-time stable. • Adaptive law is applied to deal with the external disturbances. [ABSTRACT FROM AUTHOR]

Abstract To meet the spacecraft attitude control requirements with high accuracy and stability, all vibrations in the spacecraft should be reduced in appropriate ways. This paper presents an integrated control method for attitude and the vibrations in both high frequency and low frequency in the spacecraft. The integrated control method includes a vibration isolation platform and a modified adaptive attitude control method. The paper presents a vibration isolation platform with magnetic suspension to reduce high frequency vibrations and a parameter design method for the platform. An adaptive control method is presented to reduce low frequency vibrations while accounting for the bandwidth constraint due to the vibration isolation platform. Firstly, a parameter design method is proposed for the vibration isolation platform, and an entire 6 × 12 dimensional transformation matrix is derived for the case that the inertia of the payload is of the same order of magnitude as that of spacecraft bus. Then, an adaptive attitude controller is presented that accounts for the coupling characteristics of the spacecraft, the vibration isolation platform and the uncertain or unknown payload inertia parameters. To ensure the robustness of the attitude control system and the performance of the vibration isolation system, a method of estimating the initial value of the payload inertia is presented using classical control theory. Finally, numerical simulations demonstrate that the integrated control method presented in this paper can achieve the attitude control task for spacecraft with high accuracy and stability. Highlights • An integrated jitter control method for both high and low frequencies is presented. • The entire 6 × 12 dimensional transformation matrix of the platform is derived. • An adaptive attitude controller with inertia estimation is presented. • Parameter design method is proposed for adaptive attitude controller. [ABSTRACT FROM AUTHOR]

Interplanetary human missions to Mars and beyond will suppose a very demanding physical and psychological environment for future astronauts. Isolation, confinement, hypoxia or hypercapnia in a less pressurized atmosphere, darkness and other factors are expected to endanger a mission's success, directly influencing human performance. In order to study the effects of such environmental conditions on human beings, the SIMSKILL Experiment aims to investigate how spacecraft piloting performance decays over time by deploying a Soyuz flight simulator on the Antarctic research stations Halley VI and Concordia, which feature similar living conditions as those of a space mission, leading eventually to muscular atrophy, loss of cognitive capacities, and reduction of psycho-motor skills. This paper offers an analysis on the recorded data from the scientific campaigns in Antarctica, compared to those of the subjects in a control group in Stuttgart, Germany. An overall total of 69 subjects and more than one thousand approach and docking flights to the ISS performed in a Soyuz-TMA simulator have been analysed using a performance assessment methodology. The post-processed simulation dataset allows to recognize collective trends and find which are the essential parameters that affect the pilot's skill evolution. The results obtained from this analysis show how the influence of isolation, confinement and hypoxia in Antarctica is crucial to understand how differences in performance appear between subjects. The significance of the obtained results has been proven by means of statistical models, which show that a one-month training refreshing delivers satisfactory performance for a docking simulation, whereas a frequency of 3 months follows to a loss of piloting reliability. Moreover, the effect of isolation and hypoxia aggravates the loss of flight performance. • Use of a Soyuz space flight simulator for the analysis of flight performance. • International Space Station approach and docking procedures prove to be an optimal testbed for human performance analysis. • Antarctic isolation and confinement conditions cause a degradation on spacecraft piloting performance. • Training intervals of three months show a decrease on flight performance and reliability. • The hypoxic environment at the Concordia Station exacerbates the decay of piloting skills. [ABSTRACT FROM AUTHOR]

Percolating reaction–diffusion waves in disordered random media are encountered in many branches of modern science, ranging from physics and biology to material science and combustion. Most disordered reaction–diffusion systems, however, have complex morphologies and reaction kinetics that complicate the study of the dynamics. Flames in suspensions of heterogeneously reacting metal-fuel particles is a rare example of a reaction–diffusion wave with a simple structure formed by point-like heat sources having well-defined ignition temperature thresholds and combustion times. Particle sedimentation and natural convection can be suppressed in the free-fall conditions of sounding rocket experiments, enabling the properties of percolating flames in suspensions to be observed, studied, and compared with emerging theoretical models. The current paper describes the design of the European Space Agency PERWAVES microgravity combustion apparatus, built by the Airbus Defense and Space team from Bremen in collaboration with the scientific research teams from McGill University and the Technical University of Eindhoven, and discusses the results of two sounding-rocket flight experiments. The apparatus allows multiple flame experiments in quartz glass tubes filled with uniform suspensions of 25-micron iron particles in oxygen/xenon gas mixtures. The experiments performed during the MAXUS-9 (April 2017) and TEXUS-56 (November 2019) sounding rocket flights have confirmed flame propagation in the discrete mode, which is a pre-requisite for percolating-flame behavior, and have allowed observation of the flame structure in the vicinity of the propagation threshold. • Percolating reaction–diffusion waves in disordered heterogeneous media. • Flames in suspensions of iron particles aboard MAXUS-9 & TEXUS-56 sounding rockets. • Iron powder as carbon-free carrier of green energy. [ABSTRACT FROM AUTHOR]

The author reported for duty 51 years ago, in the summer of 1968, to the NASA Goddard Space Flight Center, one month after graduating with honors from the University of Maryland. Her position was entry level Aerospace Technologist (AST), within the Data Operations Branch of the Manned Flight Planning and Analysis Division. Her duties included the testing and development of the Goddard Real Time System (GRTS) to assure operational readiness for Apollo missions, beginning with Apollo 7. Her role in Apollo 11 was to operate the GRTS to record radar data from the Manned Space Flight Network (MSFN) tracking sites and use this data to update the orbit and send out acquisition messages to the MSFN. The author's fondest memory of the Apollo program, especially Apollo 11, was that, with less than one year of Government service, she had the opportunity to work among the "giants" of NASA to contribute to the success of something that had never been done before. The awe and wonder of Apollo continued past the moon landing in 1969, through the entire program, including the Apollo-Soyuz Test Program in 1975. The "Apollo Mentality" guided the author through 46 years at NASA, encompassing the highs of camaraderie and the lows of discrimination. The camaraderie lasted one year until a manager asked why she was not pregnant. Thus began the discrimination, more specifically gender harassment. This paper addresses how the "girl" accommodated the conflicting behaviors through the lens of the "Apollo Mentality" during her NASA tenure. • Rhoda Hornstein role in Apollo 11 was to operate the Goddard Real Time System. • The Apollo Program was an opportunity to work. • After one year on the job began the discrimination, more specifically gender harassment. • How the "girl" accommodated through the lens of the "Apollo Mentality" during her NASA career. [ABSTRACT FROM AUTHOR]

Space exploration has seen a growing number of asteroid missions being launched; mostly due to their scientific interest, but also on account of the potential impact threat and prospective valuable resources of their targets. Landing safely on the surface of an asteroid is one of the main technical challenges before obtaining in-situ observations and ground-truth data. Given the asteroid's extremely weak gravitational field, purely ballistic descent trajectories become a suitable option to reach its surface. However, this is still a very risky operation due to the limited knowledge of the object's physical characteristics. Hence, deploying a small lander is often a more conservative option than endangering the mothercraft itself, and thus a simple CubeSat may provide a low cost solution for asteroid exploration. However, for a CubeSat system to be able to safely land on the surface of an asteroid, a sufficient dissipation of energy must naturally occur at touchdown, or else the resultant bouncing may lead to high uncertainties on the final landing location, or even yield an escape trajectory. This paper describes the result of ESA Academy's Drop Your Thesis! 2018 (DYT2018) programme. DYT2018 carried out a microgravity experiment, led by Land3U team from the Astronautics and Space Engineering Course at Cranfield University, to provide additional data on the engineering constraints relevant to land a CubeSat on the surface of an asteroid. The experiment was performed in ZARM's Drop Tower, located in Bremen, during two Drop campaigns in November 2018 and February 2019. A total of 7 drops were completed, each providing 4.74 s of microgravity under vacuum environment. The experiment measured the coefficient of restitution of a 1U mock-up, equipped with a 4-kg mass, touching down on the simulated asteroid surface with an average velocity of 150 mm/s. Three successful drops measured a coefficient of restitution of 0.26 ± 0.03. • An experiment to analyse lander-surface interaction in microgravity conditions. • The experiment was made possible by ESA Academy's Drop Your Thesis! 2018 programme. • The coefficient of restitution of a 4-kg CubeSat landing on an asteroid is measured. • Three successful drops measured a coefficient of restitution of 0.26 ± 0.03 • The results inform future asteroid landing strategies. [ABSTRACT FROM AUTHOR]

The Arctic has become an area of particular relevance, where manifold interests meet with particular challenges, such as the harsh environment, a limited infrastructure and a low population density. Since many years, the European Space Agency (ESA) supports its Member States with interests in the Arctic. A variety of ESA programmes are directly or indirectly targeting the Arctic area for scientific purposes, for a better understanding of the Arctic environment or to support other activities in the Arctic region, since many of the specific challenges of the Arctic can be addressed by space technology. Monitoring and assessing the Arctic environment are tasks best met with space systems. Satellite technology facilitates navigation and communication and improves marine safety, and it enables the comprehension of climate change impacts, which are particularly evident and dramatic in the Arctic. While the Sustainable Development Goals (SGDs), which were adopted by UN Member States in 2015, apply globally, the Arctic is especially affected by the changing climate and thus considered to be of great interest to the European and international community. ESA fully supports and works towards attaining the SGDs, and has to this end created a toolbox to target each of the 17 goals. Given the technological capabilities of ESA as well as the Agency's commitment to the SDGs, ESA continues to strengthen its contributions towards a sustainable economic development in the Arctic. After providing a general introduction to the Arctic and its legal status, as well as an overview over different interests in the region, this paper details the numerous ways, in which space activities can contribute to the sustainable development and life in the Arctic. It then turns to retracing the specific steps taken in the European Space Agency, including the work of specific Arctic Task Forces, and gives an outlook on future projects in support of a sustainable Arctic. • The Arctic, heavily affected by climate change, is vital for the global community. • Monitoring and assessing Arctic environment are tasks best met with space systems. • ESA, working on attaining the 17 SGDs, has created a toolbox to target each of them. [ABSTRACT FROM AUTHOR]

Strength of Space vehicles is a crucial issue for Space flight safety. The presence of latent defects in the material has a significant effect on the strength at different loads: the speed and direction of crack growth. In this paper, we study a three-dimensional elastic medium weakened by a system of plane cracks and one crack with a bend. As a numerical method, the method of boundary elements was chosen, namely, the method of discontinuous displacements. The code is implemented in C ++. A comparison was made with known analytical results. Bend crack behavior is studied for various loads. • Cracks with a bend always begin to grow along the bend line. • Numerically developed stress intensity factors are in good agreement with analytical solutions. • Two plane fractures interaction in space being located at an angle was investigated. • Stress intensity factor depends on the nature of the applied load. [ABSTRACT FROM AUTHOR]

NASA is working to increase the likelihood of exploration mission success and to maintain crew health, both during exploration missions and long term after return to Earth. To manage the risks in achieving these goals, a system modelled after a Continuous Risk Management framework is in place. “Human System Risks” (Risks) have been identified, and 32 are currently being actively addressed by NASA's Human Research Program (HRP). Research plans for each of HRP's Risks have been developed and are being executed. Inter-disciplinary ties between the research efforts supporting each Risk have been identified; however, efforts to identify and benefit from these connections have been mostly ad hoc. There is growing recognition that solutions developed to address the full set of Risks covering medical, physiological, behavioural, vehicle, and organizational aspects of exploration missions must be integrated across Risks and disciplines. This paper discusses how a framework of factors influencing human health and performance in space is being applied as the backbone for bringing together sometimes disparate information relevant to the individual Risks. The resulting interrelated information enables identification and visualization of connections between Risks and research efforts in a systematic and standardized manner. This paper also discusses the applications of the visualizations and insights into research planning, solicitation, and decision-making processes. [ABSTRACT FROM AUTHOR]

A team of leading United Kingdom (UK) space companies, in collaboration with the Raspberry Pi Foundation (RPF), created the Astro Pi project ( www.astro-pi.org ) in order to exploit the outreach possibilities offered by the flight of British European Space Agency (ESA) astronaut Tim Peake to the International Space Station (ISS) between December 2015 and June 2016. At the core of the project is the Astro Pi payload, which was developed to be taken to the ISS and into classrooms. It consists of a Raspberry Pi B+ computer, an add-on board called the Sense Hardware Attached on Top (HAT), a camera, a joystick, and six push buttons. The Sense HAT board was designed to host a range of sensors and input/output devices to be used for experiments aboard the ISS and in the classroom. The payload was qualified for spaceflight in 2015, and a competition was run to promote engagement between schools and the UK space industry that was supported by a range of learning resources. The payload was launched into space on the Orbital Sciences OA-4 Cygnus cargo freighter in December 2015, and the winning experiments were run on the ISS by Tim Peake in early 2016. These generated a range of data for analysis on the ground. Between February and March 2016, a second competition was run. In both competitions, the prize was to have students' code uploaded and run on the Astro Pi payload by Tim Peake. This paper is divided into four sections. The first provides details of the Cygnus launch and flight operations aboard the ISS. The second reviews the results of the first competition, and how these were distributed and analysed by the schools. The third covers the second competition including its results, impact, and engagement. The fourth details ongoing outreach, events, and the establishment of a long-term legacy for Astro Pi. This paper continues the work in the 2015 paper ASTRO PI: LAUNCH YOUR CODE INTO SPACE (IAC-15-E1.2.1); readers may consult the original paper for context first. [ABSTRACT FROM AUTHOR]

The close observation of orbiting objects with Cubesats can efficiently support a wide range of applications, such as the inspection of defunct satellites for preparing active debris removal missions, or the inspection of operative spacecraft (International Space Station, telecom satellites) for maintenance purposes. Future applications can involve inspection of deep space objects, for example the cis -lunar human-tended station, that will constitute the Gateway for future exploration missions. From the ISS mission, it has been understood that an inhabited outpost in space needs heavy maintenance for keeping it in operations with the required capabilities and safety level over a long-duration mission. Inspection from outside the station is required for investigation on detected anomalies or for preventing failures, for structural measurements, and in general for monitoring the station configuration. Small space (semi)autonomous drones, such as CubeSats, can be deployed from transportation vehicles or from the station, and used in several phases of the mission, flying in the vicinity of the space habitat. The study presented in this paper investigates the feasibility of operating multi-purpose small inspectors in proximity of the future Lunar Orbiting Platform. The study focuses on the inspection/surveillance mission, for which a concept of operations and architecture have been developed and analysed. In particular, the possibility to have 3D vision and multispectral payloads has been investigated, to enhance inspection capabilities with respect to current state-of-the-art technology. • Close observation of spacecraft with CubeSats in the vicinity of the target. • Mission concept for the inspection of LOP-G with small (semi)autonomous drones. • Analysis of mission challenges for safe and effective proximity operations. • Analysis of motion control requirements, technology development, and safety aspects. • Imaging (3D vision and multispectral) payloads for detection of target features. [ABSTRACT FROM AUTHOR]

Recently, the fast rendezvous profile trend is observed in the manned spaceflight domain. Since 2012, docking of 28 Russian vehicles (18 of them were Soyuz crew vehicles) has been accomplished using the 6-h and 4-orbit rendezvous profile. The heritage and the return of experience from those flights made possible to develop and implement a two-orbit rendezvous with an unmanned Progress vehicle in 2018 that demonstrated the feasibility to develop and fly a fast rendezvous with Soyuz in 2020. The fast rendezvous profile will bring the crew vehicle to docking point in just 3 h after the insertion into orbit. Furthermore, in the future an ultrafast (one-orbit) rendezvous profile is considered as well. Crew comfort on the way to the ISS is just one of the advantages of the fast rendezvous profile which will also be required to develop the double-launch approach for the transfer to a lunar station. Since the double-launch approach considers separate launches of the crew vehicle and the upper stage, this allows arranging an effective traffic toward the Moon using launch vehicles of lower capacity. Launches at different times will allow the crew vehicle to wait for a successful launch of the upper stage while being docked to the orbital station, and that will give much higher reliability of the double-launch scenario. In the future, double-launch scenarios which include visiting an orbital station could be applied to reusable spacecraft transit from the orbital station to the lunar station and back. Fast rendezvous is especially favorable for double-launch scenarios because of the upper stage's limited lifetime if fueled with low boiling point propellant components. The paper reviews the evolution of the fast rendezvous profiles which were initially used in the ISS program for further utilization of this experience for development of rendezvous concepts in double-launch scenarios for missions to a lunar station. • A retrospective experience of double-launch approach, since Gemini program is considered. • An evolution of fast rendezvous profiles implemented during Soyuz spacecraft flights to the ISS is considered. • A fast rendezvous profile with using a near-earth orbital station for a double-launch scenario of flight to the Moon is proposed. [ABSTRACT FROM AUTHOR]

The E. coli AntiMicrobial Satellite (EcAMSat) was a successful spaceflight mission that performed an autonomous experiment to investigate the effects of microgravity on the antibiotic resistance of uropathogenic E. coli ; the latest in a series of biology-focused CubeSats developed at NASA Ames Research Center. While maintaining the bacteria at 37 °C, the payload delivered growth medium, different doses of the antibiotic gentamicin, and finally the metabolic indicator alamarBlue to each of 48 microwells in the fluidic card. An LED and detector system was used to monitor the changes in absorbance in each experiment well at three wavelengths (470, 525, and 615 nm), from which the growth of cells and their metabolic activity could be measured. The success of the mission was in part due to leveraging lessons learned and proven technologies from previous bio-CubeSat missions, including modified spare hardware from the PharmaSat payload. This paper details the design and assembly of the biofluidic system payload; the modifications to the PharmaSat hardware required to run the EcAMSat experiment and the challenges those changes created; and finally, the testing approach employed to ensure the success of the payload during the flight campaign. • EcAMSat : another successful NASA Ames bio-CubeSat spaceflight mission. • Lessons learned from previous missions incorporated into fluidic design and testing. • Vital to characterize and manage pressure in autonomous fluidic system. • Systematic testing approach needed to select flight-worthy fluidic cards. • Component and system-level biocompatibility testing ensured organism survival. [ABSTRACT FROM AUTHOR]

Japan's second asteroid explorer Hayabusa2 was successfully launched on Dec 3, 2014, to return a sample from asteroid 162173 Ryugu by 2020. Four xenon ion thrusters based on electron cyclotron resonance discharge propelled the spacecraft for 547 h during its first year in space. Hayabusa2 completed an Earth gravity assist on Dec 3, 2015, followed by 798 and 2593 h of ion thruster operation, called the first and second transfer phases of delta-v, respectively. The third transfer phase of delta-v was conducted from Jan 10, 2018, to Jun 6, 2018, in which the final 2475-h ion thruster operation was executed before the rendezvous with Ryugu. The cumulative operating times for the four ion thrusters are 6,450, 11, 5,193, and 6418 h. This paper summarizes the 6515-h powered flight by the ion engine system, which produced 1015 m/s delta-v, in terms of thruster performance change, roll torques generated by various combinations of ion thrusters, and spacecraft surface erosion history measured by two quartz crystal microbalances located near the thrusters. In parallel with the space flight operation, an engineering model of the microwave discharge neutralizer has been under long-duration testing on the ground since 2012. It has accumulated 55,170 h of diode-mode operation as of Mar 15, 2019. • Hayabusa2, JAXA's asteroid explorer arrived at its destination, asteroid Ryugu. • A cluster of four microwave discharge ion engines worked very well. • The cumulative operation time was 6515 h, producing 1015 m/s delta-v. • An engineering model of the neutralizer has passed 55,170 h of ground operation. [ABSTRACT FROM AUTHOR]

In order for astronauts to live and work in outer space, environmental conditions must be maintained within very strict parameters. Any change in these conditions (such as atmospheric composition, pressure, and/or temperature) could pose a risk to the astronauts and ultimately to the success of the mission itself. In particular, changes in pressure could place the astronaut at risk for decompression illness (DCI), a potentially life-threatening condition related to the presence of nitrogen bubbles within the body. There are a number of strategies in human spaceflight designed to minimize the risk of DCI or treat it if necessary. However, as humans prepare again to travel beyond Low Earth Orbit (LEO), the risk of developing DCI may increase, as would the difficulties in treating it, given that evacuation to Earth will become substantially less feasible. Even though hyperbaric oxygen therapy (HBOT) is the accepted gold standard for the treatment of DCI on Earth, there is currently limited capacity for this treatment option in space. Expanding HBOT capacity in human spaceflight could prove useful, given that this medical capability can also be used for the treatment of a number of other potentially life-threatening conditions, such as carbon monoxide poisoning, thermal burns, and gangrene. This paper will examine the current issues related to HBOT in space and discuss the opportunities for its use in future human spaceflight endeavors. • Decompression illness occurs less frequently in space than would be predicted. • Missions beyond Low Earth Orbit will involve partial gravity environments. • Astronauts on such missions would likely have an increased risk of DCI. • Technologies exist to deliver hyperbaric oxygen treatment in space. • HBOT should be considered for future space missions beyond LEO. [ABSTRACT FROM AUTHOR]

Protection of on board electronic devises subjected to high-frequency electromagnetic emission is a crucial problem of Space flight safety. The present paper contains the results of theoretical investigation of the effects of high frequency electromagnetic radiation on a moving conductive screen. Methods are developed and results are presented aimed at evaluating conductive screen protective properties depending on thermophysical and electromagnetic properties of material, radiation intensity and frequency, as well as relative velocity of the radiation source and the target. • Protection of on board electronic devises is studied to ensure Space flight safety. • The effects of high frequency electromagnetic radiation on a conductive screen are studied. • Methods are developed evaluating conductive screen protective properties. • The role of material properties, radiation intensity and frequency and relative velocity is studied. [ABSTRACT FROM AUTHOR]

The InflateSail (QB50-UK06) CubeSat, designed and built at the Surrey Space Centre (SSC) for the Von Karman Institute (VKI), Belgium, was one of the technology demonstrators for the European Commission's QB50 programme. The 3.2 kg 3U CubeSat was equipped with a 1 m long inflatable mast and a 10 m2 deployable drag sail. InflateSail's primary mission was to demonstrate the effectiveness of using a drag sail in Low Earth Orbit (LEO) to dramatically increase the rate at which satellites lose altitude and re-enter the Earth's atmosphere and it was one of 31 satellites that were launched simultaneously on the PSLV (polar satellite launch vehicle) C-38 from Sriharikota, India on 23rd June 2017 into a 505 km, 97.44° Sun-synchronous orbit. Shortly after safe deployment in orbit, InflateSail automatically activated its payload. Firstly, it inflated its metre-long metal-polymer laminate tubular mast, and then activated a stepper motor to extend four lightweight bi-stable rigid composite (BRC) booms from the end of the mast, so as to draw out the 3.1 m × 3.1 m square, 12 μm thick polyethylene naphthalate (PEN) drag-sail. As intended, the satellite immediately began to lose altitude, causing it to re-enter the atmosphere just 72 days later – thus successfully demonstrating for the first time the de-orbiting of a spacecraft using European inflatable and drag-sail technologies. The InflateSail project was funded by two European Commission Framework Program Seven (FP7) projects: DEPLOYTECH and QB50. DEPLOYTECH had eight European partners including DLR, Airbus France, RolaTube, Cambridge University, and was assisted by NASA Marshall Space Flight Centre. DEPLOYTECH's objectives were to advance the technological capabilities of three different space deployable technologies by qualifying their concepts for space use. QB50 was a programme, led by VKI, for launching a network of 50 CubeSats built mainly by university teams all over the world to perform first-class science in the largely unexplored lower thermosphere. The mast/drag-sail technology developed by SSC will next be used on a third FP7 Project: RemoveDebris, launched in 2018, which will demonstrate the capturing and de-orbiting of artificial space debris targets using a net and harpoon system. This paper describes the results of the InflateSail mission, including the observed effects of atmospheric density and solar activity on its trajectory and body dynamics. It also describes the application of the technology to RemoveDebris and its potential as a commercial de-orbiting add-on package for future space missions. • Description of the InflateSail QB-50 Spacecraft and mission and its results. • First demonstration of cool gas generator inflated inflatable structures in Europe. • First successful European demonstration of using a drag sail to cause re-entry of a spacecraft. • First detailed observations of orbit and body descent using such technology. • Discussion of future application to tackling the space debris problem. [ABSTRACT FROM AUTHOR]

Since Apollo it has been necessary to ensure the safety of spaceflight structures by fracture control and damage tolerance methods. Fracture and damage control cover a wide range of structural and materials engineering disciplines. This paper presents a brief overview of the history, the current state of art, and new developments in implementing fracture and damage control to assure spaceflight structural integrity. • Fracture control has been developed and applied successfully to prevent catastrophic failure. • Fracture control is now a standard element in the verification of ESA's spaceflight hardware. • Technologies (fracture mechanics, NDI, material research) and standards are constantly improved. • Related ESA R&D results are implemented in analysis tools, which are made available to industry. • Challenges are adequate and efficient implementation for crewed and uncrewed critical missions. [ABSTRACT FROM AUTHOR]

Streaked point sources are a common occurrence when imaging unresolved space objects from both ground- and space-based platforms. Effective localization of streak endpoints is a key component of traditional techniques in space situational awareness related to orbit estimation and attitude determination. To further that goal, this paper derives a general detection and localization method for streak endpoints based on the cornerness metric. Corners detection involves searching an image for strong bi-directional gradients. These locations typically correspond to robust structural features in an image. In the case of unresolved imagery, regions with a high cornerness score correspond directly to the endpoints of streaks. This paper explores three approaches for global extraction of streak endpoints and applies them to an attitude and rate estimation routine. [ABSTRACT FROM AUTHOR]

The International Academy of Astronautics (IAA) Symposia on the History of Rocketry and Astronautics have been held annually at the International Astronautical Congresses since 1967. During these past 50 years nearly 800 papers have been presented and subsequently published in the proceedings. With a 20-year rule imposed for historical presentations, the first 10 symposia concentrated on pre-World War II and early 1950s activities. A surprisingly large number of papers on early, less well-known Soviet-Russian contributions to rocketry and astronautics were presented in the first symposia, despite the ongoing Space Race between the U.S and USSR. Another important element in these symposia involved memoir papers offered by pre- and post-war rocket and astronautics pioneers from many countries, and the participation of many of these pioneers in person. In sum, the history of national space and rocket projects from some 40 countries were presented over the years in IAA History Symposia. These 50 symposia have provided a platform for scholars and professional and non-professional historians to meet and discuss the history of rocketry and astronautics, and to personally interview many space pioneers, most of whom today are deceased. Their personal recollections have since been shared with a large audience. Over time, IAA history papers divided into recognizable periods: ancient times through the 19th century, and the 20th and 21st centuries, which separate among actions and events that took place before 1945, in 1945 to 1957, and after 1957 (which marked the beginning of the space age). Proceedings of the IAA History Symposia have been published in English, ultimately in the History Series of the American Astronautical Society (AAS) and its publishing arm, Univelt Inc., under an agreement secured with the IAA. This paper presents an overview of the IAA History Symposia. It examines the early years of the history committee and its first symposium, the evolution of subsequent symposia, and it recognizes those individuals who shaped these symposia and the publication of its proceedings. [ABSTRACT FROM AUTHOR]

Solar oscillation, which causes the sunlight intensity and spectrum frequency change, has been studied in great detail, both observationally and theoretically. In this paper, owing to the existence of solar oscillation, the time delay between the sunlight coming from the Sun directly and the sunlight reflected by the other celestial body such as the satellite of planet or asteroid can be obtained with two optical power meters. Because the solar oscillation time delay is determined by the relative positions of the spacecraft, reflective celestial body and the Sun, it can be adopted as the navigation measurement to estimate the spacecraft's position. The navigation accuracy of single solar oscillation time delay navigation system depends on the time delay measurement accuracy, and is influenced by the distance between spacecraft and reflective celestial body. In this paper, we combine it with the star angle measurement and propose a solar oscillation time delay measurement assisted celestial navigation method for deep space exploration. Since the measurement model of time delay is an implicit function, the Implicit Unscented Kalman Filter (IUKF) is applied. Simulations demonstrate the effectiveness and superiority of this method. [ABSTRACT FROM AUTHOR]

NASA planning for the human space flight frontier is coming into alignment with the goals of other planetary-capable national space agencies and independent commercial actors. US Space Policy Directive 1 made this shift explicit: "the United States will lead the return of humans to the Moon for long-term exploration and utilization". The stage is now set for public and private American investment in a wide range of lunar activities. Assumptions about Moon base architectures and operations are likely to drive the invention of requirements that will in turn govern development of systems, commercial-services purchase agreements, and priorities for technology investment. Yet some fundamental architecture-shaping lessons already captured in the literature are not clearly being used as drivers, and remain absent from typical treatments of lunar base concepts. A prime example is general failure to recognize that most of the time (i.e., before and between intermittent human occupancy), a Moon base must be robotic: most of the activity, most of the time, must be implemented by robot agents rather than astronauts. This paper reviews key findings of a seminal robotic-base design-operations analysis commissioned by NASA in 1989. It discusses implications of these lessons for today's Moon Village and SPD-1 paradigms: exploration by multiple actors; public-private partnership development and operations; cislunar infrastructure; production-quantity exploitation of volatile resources near the poles to bootstrap further space activities; autonomy capability that was frontier in 1989 but now routine within terrestrial industry. It outlines new work underway to close these gaps; and articulates conclusions that can guide future work. • Most of the time, most of a Moon base is robotic. • Base elements designed for robotic operations challenge conventional concepts. • Hierarchical supervisory control is essential. Full autonomy is not. • All known base functions can be emplaced completely robotically. • A habitable, oxygen-producing base can be constructed in less than four years of quarterly flights. [ABSTRACT FROM AUTHOR]

Abstract This paper investigates the robust control for spacecraft without angular velocity measurement subject to the external disturbances and input saturation constraints. A novel integral sliding mode surface that is suitable to solve the problem of input saturation constraints is established based on the hyperbolic tangent function. Both controllers can deal with the actuator saturation and external disturbances simultaneously by using the sliding mode surface. The first controller is full state feedback, while the second one just contains attitude information, where the angular velocity is unnecessary due to the existence of a finite-time observer. Finally, Lyapunov theory and simulation results are provided to illustrate the effectiveness of the controllers. Highlights • A novel integral sliding mode surface is established based on the hyperbolic tangent function. • A novel finite-time velocity observer is designed to estimate the angular velocity. • Both robust sliding mode controllers can deal with the actuator saturation. • The second robust controller is the output feedback by using the finite-time velocity observer. [ABSTRACT FROM AUTHOR]