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The effects of space environment on friction and wear and on the selection of lubricants and self‐lubricating materials for spacecraft mechanisms are discussed, with special emphasis on the ultrahigh vacuum of space. Experimental studies have demonstrated the feasibility of using selected oils and greases to lubricate lightly loaded ball bearings without replenishment for periods of over one year under the following conditions of operation : speeds of 8,000 rpm, temperatures of 160 to 200°F., and vacuum of 10–8 torr. Over one‐half year of successful operation has been achieved under similar operating conditions with self‐lubricating retainers of reinforced Teflon, provided that the loads were light. Bonded films of molybdenum disulfide have given shorter lifetimes and poor repro‐ducibility. Metal‐to‐metal slip‐ring contacts introduce excessive electrical noise into circuits when operated in vacuum of 10–7 torr. The noise (as well as the friction and wear) can be markedly reduced by providing a small amount of oil vapor, sufficient to maintain a pressure on the order of 10–6 torr, or by incorporating molybdenum disulfide into the brush material.

This paper identifies component industry trends, examines the traditional methods of achieving “space quality”, addresses how the space industry can adapt to this changing scenario, looks at the options for space standardisation/qualification, challenges some established practices and, finally, considers performance specifications.

Concerning the radiation effects on the three-dimensional (3D) packaging in space environment, this study aims to investigate the influence of the total dose effect on the transmission characteristics of high-frequency electrical signals using experimental and simulation methods.

This work carries out the irradiation test of the specimens and measures their S21 parameters before and after irradiation. A simulation model describing the total dose effect was built based on the experimental test results. And, the radiation hardening design is evaluated by the simulation method.

The experimental results demonstrate that the S21 curve of the interconnection decreases with the increase of the irradiation dose, indicating that the total dose effect leads to the decline of its signal transmission characteristics. According to the simulation results, decreasing the height of the through silicon via (TSV), increasing the radius of the TSV, reducing the length of Si and increasing the number of grounded through silicon via have positive effects on improving the radiation resistance of the interconnection structure.

This work investigates the effect of radiation on the transmission characteristics of interconnection structures for 3D packaging and proposes the hardening design methods. It is meaningful for improving the reliability of 3D packaging in space applications.

The purpose of this paper is to report the results of a recent project of complex tests on the survival of structural health monitoring (SHM) technology with piezo wafer active sensors (PWAS) and electromechanical impedance spectroscopy (EMIS) at simulating the concomitant action of harsh conditions of outer space: extreme temperatures, radiations, vacuum.

The tests were conducted on PWAS, consists in adhesive and aluminium discs as structural specimens, with PWAS bonded on them. The substantiating of PWAS-EMIS-based SHM technique consists the fact that real part of the PWAS electromechanical impedance spectrum follows with fidelity the resonance behaviour of the structure vibrating under the PWAS excitation. This EMIS signature is very sensitive to any structural changes and, on this basis, can be monitored the onset and progress of structural damages such as fatigue, cracks, corrosion, etc.

The conclusion of the tests is that the cumulative impact of severe conditions of temperature, radiation and vacuum has not generated decommissioning of sensors or adhesive, which would have meant the compromise of the methodology. A second important outcome is linked to the capability of this methodology to distinguish between the damages of mechanical origin and the false ones, caused by environmental conditions, which are, basically, harmless.

The question of transfer of PWAS-EMIS-based SHM technology to space vehicles and applications received, as a novelty, a first and encouraging response.

The purpose of this paper is to present a novel algorithm to handle space environment induced errors in the space‐robot software.

The radiations in outer space may induce transient errors in micro‐processors, this phenomena will make software behavior unpredictable, and the existing software fault tolerance methods have been restricted in non‐multi‐threaded operation systems, non‐component‐based frameworks, non‐cacheable micro‐processors, non‐distributed environments, etc. A software model for space‐robot software, based on adaptive redundancy, is developed and a corresponding run‐time error detection algorithm is presented in this paper. Software was monitored and run‐time transient error would be detected and processed.

Experiments indicate that this method introduces about 30‐35 percent time overhead and about 200‐230 percent memory overhead. It also increases the fault detection rate to 84‐92.5 percent. Moreover, the model and algorithm is effective in a realistic space robot environment.

A redundancy model is developed and an error detection algorithm is introduced in this paper. Experiments demonstrate it can provide space‐robot software with good protection against the radiation induced transient errors.

Space tourism is currently experiencing significant attention because of its rapid and burgeoning development in the present era. This surge has resulted in an unprecedented growth in publications dedicated to unravelling the intricacies of space tourism. However, there is a conspicuous absence of a large-scale bibliometric analysis focusing on space tourism research from 1993 to 2022. Therefore, the aim of this study is to fill this research gap by examining and mapping the scholarly output published across the world in the spectrum of space tourism over the past 30 years (1993–2022).

A corpus of 7,438 publications pertaining to space tourism published from 1993 to 2022 was gathered from the Web of Science Core Collection. Accordingly, bibliometrix package in R and VOSviewer software were used to conduct a comprehensive bibliometric analysis.

The current study highlights a significant surge in publications related to space tourism, indicating a heightened scholarly interest and a significant paradigm shift in its exploration. Scott M. Smith, affiliated with National Aeronautics Space Administration Johnson Space Center, emerges as the most prolific author. Leading journals in disseminating space tourism research are Acta Astronautica and Aviation Space and Environmental Medicine. Keyword analysis revealed hotspots such as “space flight”, “simulated microgravity”, “weightlessness” and “stress”, while research gaps include “skylab”, “shuttle”, “cartilage”, “herpes virus” and “herniation”, offering potential avenues for exploration.

This study’s implications empower stakeholders with actionable insights and deepen the understanding of the evolving landscape of space tourism research, fostering an environment conducive to continuous exploration and innovation in this burgeoning field.

This study enriches the understanding of global space tourism research and offers valuable insights applicable to a diverse audience, including researchers, policymakers and industry stakeholders. The broad applicability of the study’s findings underscores its significance, serving as a guide for strategic decision-making and shaping research agendas in the dynamic realm of space tourism.

In the Earth’s upper atmosphere, damage to satellite electronics is caused by exposure to extreme ultraviolet (EUV) radiation. One particular region where this type of radiation occurs is the South Atlantic Magnetic Anomaly region. As a result, there is a need to design and develop a sensor which could be used to investigate the flux and energy levels of radiation in this region. To do so, the aim of this study is to characterise the sensor and its electric response to typical EUV radiation levels based on the photoelectric effect principle.

For this purpose, a copper plate planar sensor prototype with dimensions that fit on the sides of a one-unit (1U) CubeSat was constructed. The sensor prototype was placed in a vacuum chamber and was subjected to continuous radiation from a vacuum ultraviolet deuterium light source at test facilities available in the Western Cape region (South Africa). Subsequently, the terminal voltage of the sensor was measured and compared with theory.

The measured time-averaged terminal voltages indicate the generation of photocurrents of the order of 1 μA, which is consistent with theory.

Conclusively, these results validate the measurement approach and operation of the sensor, which can be used to design a 1U CubeSat sensor that measures EUV radiation in low Earth orbit.

At least 35 years have passed since Slovic's (1987) seminal article on the ‘Perception of Risk’, wherein the conceptual foundations for understanding general risk and the psychometric properties underlying how individuals perceive risks were laid. Over the same time span, research on risk perception in the context of travel has become voluminous and recurrent. It is therefore fitting that in a modern, post-COVID age, Slovic's theory of risk perception is re-examined in the travel context, given the recent dramatic transformation of travel, the emergence of novel tourism-related risks and persistent scholarly attempts to understand travel risk theory. Using modern data mining methods and content analysis techniques, this chapter examines the stability and validity of long-standing categories and taxonomies of perceived travel risks, based on data archived in a sizeable database of scholarly studies related to travel risk (n = 17,790 studies), across an extensive 35-year period from 1990 to 2022. Findings infer two higher-order dimensions that likely underpin the taxonomic organization and relational ordering of different travel risk types and clusters. Findings also suggest a possible shift from Slovic's original theory in the way risks are perceived, at least in the travel context.

The purpose of this paper is to test and analyze the friction torque of double-row angular contact ball bearings under vacuum or ordinary pressure environment, horizontal or upright installation mode, and different rotational speeds, and to provide theoretical bases for the development of aerospace equipment.

The experiments were carried out to investigate the effects of vacuum or ordinary pressure environment, horizontal or upright installation mode and different rotational speeds on bearing friction torque. To explore the relationship between working conditions and bearing friction torque, firstly, based on the generation source of friction torque, the test principle was determined, a test system was developed and the reliability of data was verified. Secondly, the friction torque of bearing was tested, and the values under various working conditions were obtained. Finally, this paper compared and discussed the test results.

The test results show that the friction torque value of vacuum environment horizontal installation condition is the largest at different rotational speeds, and the rotational speed has the most significant influence on the friction torque.

The friction torque test system of double-row angular contact ball bearing under vacuum environment was designed and built. The influence rules of vacuum or ordinary pressure environment, horizontal or upright installation mode and different rotational speeds on bearing friction torque were obtained.

The peer review history for this article is available at: http://dx.doi.org/10.1108/ILT-08-2023-0259