Forecast analysis on satellites that need de-orbit technologies: future scenarios for passive de-orbit devices

Propulsion-based de-orbit is a space-proven technology; however, this strategy can strongly limit operational lifetime, as fuel mass is dedicated to the de-orbiting. In addition previous reliability studies have identified the propulsion subsystem as one of the major contributors driving satellite failures. This issue brings the need to develop affordable de-orbit technologies with a limited reliance on the system level performance of the host satellite, ideally largely passive methods. Passive disposal strategies which take advantage of aerodynamic drag as the de-orbit force are particularly attractive because they are independent of spacecraft propulsion capabilities. This paper investigates the future market for passive de-orbit devices in LEO to aid in defining top-level requirements for the design of such devices. This is performed by considering the compliances of projected future satellites with the Inter Agency Space Debris Coordination Committee de-orbit time, to quantify the number of spacecraft that are compliant or non-compliant with the guidelines and, in this way, determine their need for the previously discussed devices. The study is performed by using the SpaceTrak™ database which provides future launch schedules, and spacecraft information; the de-orbit analysis is carried out by means of simulations with STELA. A case study of a passive strategy is given by the de-orbit mechanism technological demonstrator, which is currently under development at Cranfield University and designed to deploy a drag sail at the end of the ESEO satellite mission

Plant responses to decadal scale increments in atmospheric CO2 concentration: comparing two stomatal conductance sampling methods

There are several lines of evidence suggesting that the vast majority of C3 plants respond to elevated atmospheric CO2 by decreasing their stomatal conductance (gs). However, in the majority of CO2 enrichment studies, the response to elevated CO2 are tested between plants grown under ambient (380–420 ppm) and high (538–680 ppm) CO2 concentrations and measured usually at single time points in a diurnal cycle. We investigated gs responses to simulated decadal increments in CO2 predicted over the next 4 decades and tested how measurements of gs may differ when two alternative sampling methods are employed (infrared gas analyzer [IRGA] vs. leaf porometer). We exposed Populus tremula, Popolus tremuloides and Sambucus racemosa to four different CO2 concentrations over 126 days in experimental growth chambers at 350, 420, 490 and 560 ppm CO2; representing the years 1987, 2025, 2051, and 2070, respectively (RCP4.5 scenario). Our study demonstrated that the species respond non-linearly to increases in CO2 concentration when exposed to decadal changes in CO2. Under natural conditions, maximum operational gs is often reached in the late morning to early afternoon, with a mid-day depression around noon. However, we showed that the daily maximum gs can, in some species, shift later into the day when plants are exposed to only small increases (70 ppm) in CO2. A non-linear decreases in gs and a shifting diurnal stomatal behavior under elevated CO2, could affect the long-term daily water and carbon budget of many plants in the future, and therefore alter soil–plant–atmospheric processes.Irish Research CouncilScience Foundation Irelan

Failure analysis of satellite subsystems to define suitable de-orbit devices

Space missions in Low Earth Orbit (LEO) are severely affected by the build-up of orbital debris. A key practice, to be compliant with IADC (Inter-Agency Space Debris Coordination Committee) mitigation guidelines, is the removal of space systems that interfere with the LEO region not later than 25 years after the End of Mission. It is important to note that the current guidelines are not generally legally binding, even if different Space Agencies are now looking at the compliance for their missions. If the guidelines will change in law, it will be mandatory to have a postmission disposal strategy for all satellites, including micro and smaller classes. A potential increased number of these satellites is confirmed by different projections, in particular in the commercial sector. Micro and smaller spacecraft are, in general, not provided with propulsion capabilities to achieve a controlled re-entry, so they need different de-orbit disposal methods. When considering the utility of different debris mitigation methods, it is useful to understand which spacecraft subsystems are most likely to fail and how this may affect the operation of a de-orbit system. This also helps the consideration of which components are the most relevant or should be redundant depending on the satellite mass class. This work is based on a sample of LEO and MEO satellites launched between January 2000 and December 2014 with mass lower than 1000 kg. Failure analysis of satellite subsystems is performed by means of the Kaplan–Meier survival analysis; the parametric fits are conducted with Weibull distributions. The study is carried out by using the satellite database SpaceTrak™ which provides anomalies, failures, and trends information for spacecraft subsystems and launch vehicles. The database identifies five states for each satellite subsystem: three degraded states, one fully operational state, and one failed state (complete failure). The results obtained can guide the identification of the activation procedure for a de-orbit strategy and the level of integration it should have with the host satellite in order to be activated before a total failure. At Cranfield Space Research Centre two different solutions have already been developed as de-orbit sail payloads for microsatellites (Icarus-1 on TechDemoSat-1 and Icarus-3 on Carbonite-1 currently on-orbit, DOM for future ESA ESEO mission). This study will provide a useful input to improve and refine the current de-orbit concepts for future satellite missions

‘It’s not in my job description’: An exploration of trainee clinical psychologists’ attitudes towards research and perceptions of DClinPsy research culture

© 2023 The British Psychological Society. This is the accepted manuscript version of an article which has been published in final form at https://doi.org/10.53841/bpscpf.2023.1.366.20This project aimed to investigate attitudes towards research and perceived research culture among trainee clinicalpsychologists across the UK. This was achieved by exploring factors such as: research training environment,research attitudes, research self-efficacy, and professional identity. An online survey was completed by 44 traineeclinical psychologists who started training in 2020. The findings showed that UK trainee clinical psychologistsdid not perceive a strong research training environment, they did not hold strong attitudes towards research,or have positive research self-efficacy as indicated in previous research. It is of some concern that the role ofresearcher, as part of the identity of a clinical psychologist, was not seen to be instrumental by most trainees.Important differences in the results of this research compared to previous published literature are discussed, inaddition to a consideration of the implications of these findings for training and the post-qualification role ofclinical psychologists.Peer reviewe

LEOniDAS drag sail experiment on the 2021 ESA Fly Your Thesis! parabolic flight campaign

Space engineering students and academics from Cranfield University have developed two space debris mitigation drag sail concepts and three sails are currently in orbit. The sails enable a reduced time to atmospheric re-entry by increasing the natural aerodynamic drag forces acting on the host satellite. Intended to be used on small, low Earth orbit satellites, these sails provide a low-cost solution to achieving compliance with the IADC target of removal from orbit within 25 years of end-of-mission. The LEOniDAS team, comprising one PhD and three MSc students, submitted a proposal to the ESA Fly Your Thesis! parabolic flight campaign to perform microgravity deployment testing on a more scalable and adaptable hybrid design. The project aimed to qualify the new design, provide a better understanding of deployment behaviour in microgravity and allow for a deeper understanding of the effect of deployment on the host satellite. Participation in the programme provided significant educational benefits to the students involved, resulting in three Masters theses and a major input to a PhD thesis, as well as publications and outreach activities. The experiment was presented by the students at the ESA Academy Gravity-Related Training week in January 2021. There followed extensive design, prototyping and assembly work, with regular review and input from ESA and Novespace, culminating in the two-week parabolic flight campaign in October 2021. The planned deployment experiments were successfully completed across all three flights, with the experimenters accumulating a total of more than 30 minutes of microgravity. Data on dynamics of the sail deployments was recorded via high-speed video cameras, accelerometers and torque sensors. This paper will highlight the key scientific and educational achievements of the project, and summarise the lessons learned for the benefit of future participants in this exceptional student opportunity

“I Don’t Think It’s on Anyone’s Radar”: The Workforce and System Barriers to Healthcare for Indigenous Women Following a Traumatic Brain Injury Acquired through Violence in Remote Australia

Aboriginal and Torres Strait Islander women experience high rates of traumatic brain injury (TBI) as a result of violence. While healthcare access is critical for women who have experienced a TBI as it can support pre-screening, comprehensive diagnostic assessment, and referral pathways, little is known about the barriers for Aboriginal and Torres Strait Islander women in remote areas to access healthcare. To address this gap, this study focuses on the workforce barriers in one remote region in Australia. Semi-structured interviews and focus groups were conducted with 38 professionals from various sectors including health, crisis accommodation and support, disability, family violence, and legal services. Interviews and focus groups were audiotaped and transcribed verbatim and were analysed using thematic analysis. The results highlighted various workforce barriers that affected pre-screening and diagnostic assessment including limited access to specialist neuropsychology services and stable remote primary healthcare professionals with remote expertise. There were also low levels of TBI training and knowledge among community-based professionals. The addition of pre-screening questions together with professional training on TBI may improve how remote service systems respond to women with potential TBI. Further research to understand the perspectives of Aboriginal and Torres Strait Islander women living with TBI is needed

Using research feedback loops to implement a disability case study with Aboriginal and Torres Strait Islander communities and service providers in regional and remote Australia

While there is a well-developed body of literature in the health field that describes processes to implement research, there is a dearth of similar literature in the disability field of research involving complex conditions. Moreover, the development of meaningful and sustainable knowledge translation is now a standard component of the research process. Knowledge users, including community members, service providers, and policy makers now call for evidence-led meaningful activities to occur rapidly. In response, this article presents a case study that explores the needs and priorities of Aboriginal and Torres Strait Islander women in Australia who have experienced a traumatic brain injury due to family violence. Drawing on the work of Indigenous disability scholars such as Gilroy, Avery and others, this article describes the practical and conceptual methods used to transform research to respond to the realities of community concerns and priorities, cultural considerations and complex safety factors. This article offers a unique perspective on how to increase research relevance to knowledge users and enhance the quality of data collection while also overcoming prolonged delays of knowledge translation that can result from the research-production process

Measuring older people’s socioeconomic position: a scoping review of studies of self-rated health, health service and social care use

Background The challenges of measuring socioeconomic position in older populations were first set out two decades ago. However, the question of how best to measure older people’s socioeconomic position remains pertinent as populations age and health inequalities widen. Methods A scoping review aimed to identify and appraise measures of socioeconomic position used in studies of health inequalities in older populations in high-income countries. Medline, Scopus, EMBASE, HMIC and references lists of systematic reviews were searched for observational studies of socioeconomic health inequalities in adults aged 60 years and over, published between 2000 and 2020. A narrative synthesis was conducted. Findings One-hundred and thirty-eight studies were included; 20 approaches to measuring socioeconomic position were identified. Few studies considered which pathways the chosen measures of socioeconomic position intended to capture. The validity of subjective socioeconomic position measures, and measures that assume shared income and educational capital, should be verified in older populations. Incomplete financial data risk under-representation of some older groups when missing data are socially patterned. Older study samples were largely homogeneous on measures of housing tenure, and to a lesser extent, measures of educational attainment. Measures that use only two response categories risk missing subtle differences in older people’s socioeconomic circumstances. Conclusion Poor choice of measures of socioeconomic position risk underestimating the size of health inequalities in older populations. Choice of measures should be shaped by considerations of theory, context and response categories that detect subtle, yet important, inequalities. Further evidence is required to ascertain the validity of some measures identified in this review

Drag augmentation systems for space debris mitigation

Space debris is recognised as a critical threat for the space industry. The proliferation of small satellites has invited commercialisation and subsequently, the growing number of satellites are adding to the already high number of objects currently in low-Earth orbit (LEO). Low-cost small satellites are under increasing pressure to meet debris mitigation guidelines and failure to comply could result in a launch licence being denied. Drag augmentation systems increase the drag area of a spacecraft, minimising the de-orbit period and thus reducing the probability of significant collisions and supporting the sustainable use of space. In response to the growing number of small satellites (10-500 kg) unable to de-orbit from low-Earth orbit within 25 years, Cranfield University has developed a family of drag augmentation systems (DAS). The DAS are lightweight, cost-effective sails deployed at end of mission and are reliable solutions for deorbiting small satellites, assisting in the conservation of the space environment. Three drag sails designed, manufactured and tested at Cranfield University are currently in orbit, with two sails already successfully deployed. This paper details the sails and will discuss findings from recent studies; examining the system’s scalability, the post-deployment vehicle dynamics, the medium-term impact of the sail on the satellite’s ability to conduct science and the long-term effect of the sail on the satellite’s re-entry and demise. The DAS technology have a strong enabling potential for future space activities, allowing satellites to operate responsibly and sustainably

Towards drop your thesis 2018: 4.7 seconds of microgravity conditions to enable future CubeSat landings on asteroids

An increasing number of interplanetary missions are aiming at visiting asteroids and other small bodies, since these may provide clues to understand the formation and evolution of our Solar System. CubeSats allow a low-cost solution to land on these objects, as opposed to risking a much more expensive mothership. The weak gravitational field on these small bodies may also enable the possibility of simply dropping a CubeSat from afar (i.e. ballistic landing). However, ballistic landing of an unpowered spacecraft may be feasible solely within certain asteroid locations, and only if sufficient energy can be dissipated at touchdown. If such conditions are not met, the spacecraft will rebound off the surface. It is likely that the necessary energy dissipation may already occur naturally due to energy loss expected through the deformation of the regolith during touchdown. Indeed, previous low-velocity impact experiments in microgravity seem to indicate that this is exactly the case. However, data from past asteroid touchdowns, Hayabusa and Philae, indicate the contrary. This paper describes the development of an experiment which aims to bridge the aforementioned disagreement between mission data and microgravity experiment; to understand the behaviour of CubeSat landing on asteroids. The experiment will also test a novel damping system made by origami paper that should increase the dissipated energy at touchdown. The experiment will take place at the ZARM Drop Tower in Bremen in November 2018. With the constraint of 5 drops, the experiment will measure the coefficient of restitution during an available time window of 4.74 seconds of microgravity conditions. A 1UCubeSat mock-up will be used to represent a future asteroid lander. In order to mimic the landing of actual missions, the mock-up will have a mass of about 4 kg and it will be given a velocity of 15 cm/s with minimal rotation. This will be achieved by an automated spring-based release mechanism. An asteroid simulant, ESA03-A KM Bentonite Granules will be used to replicate an asteroid mechanical properties at the surface. This paper reviews the final design and the engineering challenges of the experiment