Formation Flying and Change Detection for the UNSW Canberra Space ‘M2’ Low Earth Orbit Formation Flying CubeSat Mission

The University of New South Wales, Canberra (UNSW Canberra) embarked on an ambitious CubeSatellite research, development, and education program in 2017 through funding provided by the Royal Australian Air Force (RAAF). The program consisted of M1 (Mission 1), M2 Pathfinder, and concludes with the formation flying mission M2. M2 is the final mission comprising two 6U CubeSatellites flying in formation using differential aerodynamic drag control. The M2 satellites were launched in a conjoined 12U form factor on RocketLab’s ‘They Go Up So Fast’ launch in March 2021. On 10th September 2021 the spacecraft divided into two 6U CubeSats (M2-A and M2-B) under the action of a small spring force in their near-circular 550km, 45-degree inclination orbit. The formation is controlled by varying the spacecrafts’ attitude, which creates a large variation in the aerodynamic drag force due to the change in the cross-sectional area from the large, double-deployable, solar arrays located on the zenith face of the spacecraft. This paper presents the outcomes of the Formation Flying and Change Detection primary mission objectives for the mission. The results are generated by collecting and analysing optical and RF (Radio Frequency) space domain awareness sensor data from the ground and validating them against GPS (Global Positioning System) and attitude data downlinked from the spacecraft. The outcomes of the broader mission objectives, which include increasing the Technology Readiness Level for a suite of intelligent on-board optical and RF sensor technologies, will be presented in subsequent publications. The results presented here comprise two major campaigns: 1.) The spacecraft separation campaign when the original 12U form factor deployed following launch split in half to form the M2-A and M2-B satellites, and 2) the demonstration of active formation control of the spacecraft via differential aerodynamic drag. M2-A and M2-B underwent several major configuration changes during the spacecraft separation campaign. The results from ground-based sensors detecting the 12U spacecraft separating into two distinct (6U) objects are presented. The effect of the double-deployable solar arrays deployment on the relative orbital motion of the M2-A and M2-B spacecraft is illustrated and compared to data from optical and RF ground-based measurements taken during this window. The formation control campaign involved actively controlling the spacecraft via differential aerodynamic drag in order to significantly alter the separation distance. The mission demonstrated the capability to switch the leading spacecraft’s position between M2-A and M2-B and to actively control separation distance ranging from 130km down to 1km. Formation control is achieved via open-loop, pre-scheduled, commands issued from the UNSW Canberra Space ground station. A two-stage modelling and simulation process is used to derive the scheduled attitude states. Firstly, a batch least squares orbit determination algorithm is applied to GPS data from a steady-state differential drag actuation period (where one spacecraft is in maximum drag and the other in its minimum drag attitude configuration). The batch least squares orbit determination is conducted out using the NASA General Mission Analysis Tool (GMAT), resulting in precise state estimates for each spacecraft and drag coefficient (Cd) estimates for both the maximum and minimum drag configurations. Predictions of trajectory for various attitude profiles can be produced by tailoring the spacecraft’s drag coefficients between the maximum and minimum values generated by the batch least squares state estimation process. Ground-based optical and RF space domain awareness (SDA) sensor measurements collected during the manoeuvre campaign are compared to the spacecraft’s GPS and attitude telemetry data. The SDA sensors are actively seeking to detect changes in the separation distance between the spacecraft. Initial results from an investigation into whether changes observed in photometric light curve signatures can signal the commencement of a differential drag manoeuvre are presented

Opportunistic management of estuaries under climate change: a new adaptive decision-making framework and its practical application

Ongoing coastal development and the prospect of severe climate change impacts present pressing estuary management and governance challenges. Robust approaches must recognise the intertwined social and ecological vulnerabilities of estuaries. Here, a new governance and management framework is proposed that recognises the integrated social-ecological systems of estuaries so as to permit transformative adaptation to climate change within these systems. The framework lists stakeholders and identifies estuarine uses and values. Goals are categorised that are specific to ecosystems, private property, public infrastructure, and human communities. Systematic adaptation management strategies are proposed with conceptual examples and associated governance approaches. Contrasting case studies are used to illustrate the practical application of these ideas. The framework will assist estuary managers worldwide to achieve their goals, minimise maladaptative responses, better identify competing interests, reduce stakeholder conflict and exploit opportunities for appropriate ecosystem restoration and sustainable development

Functional Studies on the IBD Susceptibility Gene IL23R Implicate Reduced Receptor Function in the Protective Genetic Variant R381Q

Genome-wide association studies (GWAS) in several populations have demonstrated significant association of the IL23R gene with IBD (Crohn's disease (CD) and ulcerative colitis (UC)) and psoriasis, suggesting that perturbation of the IL-23 signaling pathway is relevant to the pathophysiology of these diseases. One particular variant, R381Q (rs11209026), confers strong protection against development of CD. We investigated the effects of this variant in primary T cells from healthy donors carrying IL23RR381 and IL23RQ381 haplotypes. Using a proprietary anti-IL23R antibody, ELISA, flow cytometry, phosphoflow and real-time RT-PCR methods, we examined IL23R expression and STAT3 phosphorylation and activation in response to IL-23. IL23RQ381 was associated with reduced STAT3 phosphorylation upon stimulation with IL-23 and decreased number of IL-23 responsive T-cells. We also observed slightly reduced levels of proinflammatory cytokine secretion in IL23RQ381 positive donors. Our study shows conclusively that IL23RQ381 is a loss-of-function allele, further strengthening the implication from GWAS results that the IL-23 pathway is pathogenic in human disease. This data provides an explanation for the protective role of R381Q in CD and may lead to the development of improved therapeutics for autoimmune disorders like CD

Pharmacological targeting of the transcription factor SOX18 delays breast cancer in mice.

Pharmacological targeting of transcription factors holds great promise for the development of new therapeutics, but strategies based on blockade of DNA binding, nuclear shuttling, or individual protein partner recruitment have yielded limited success to date. Transcription factors typically engage in complex interaction networks, likely masking the effects of specifically inhibiting single protein-protein interactions. Here, we used a combination of genomic, proteomic and biophysical methods to discover a suite of protein-protein interactions involving the SOX18 transcription factor, a known regulator of vascular development and disease. We describe a small-molecule that is able to disrupt a discrete subset of SOX18-dependent interactions. This compound selectively suppressed SOX18 transcriptional outputs in vitro and interfered with vascular development in zebrafish larvae. In a mouse pre-clinical model of breast cancer, treatment with this inhibitor significantly improved survival by reducing tumour vascular density and metastatic spread. Our studies validate an interactome-based molecular strategy to interfere with transcription factor activity, for the development of novel disease therapeutics

Multiple Loci Are Associated with White Blood Cell Phenotypes

White blood cell (WBC) count is a common clinical measure from complete blood count assays, and it varies widely among healthy individuals. Total WBC count and its constituent subtypes have been shown to be moderately heritable, with the heritability estimates varying across cell types. We studied 19,509 subjects from seven cohorts in a discovery analysis, and 11,823 subjects from ten cohorts for replication analyses, to determine genetic factors influencing variability within the normal hematological range for total WBC count and five WBC subtype measures. Cohort specific data was supplied by the CHARGE, HeamGen, and INGI consortia, as well as independent collaborative studies. We identified and replicated ten associations with total WBC count and five WBC subtypes at seven different genomic loci (total WBC count—6p21 in the HLA region, 17q21 near ORMDL3, and CSF3; neutrophil count—17q21; basophil count- 3p21 near RPN1 and C3orf27; lymphocyte count—6p21, 19p13 at EPS15L1; monocyte count—2q31 at ITGA4, 3q21, 8q24 an intergenic region, 9q31 near EDG2), including three previously reported associations and seven novel associations. To investigate functional relationships among variants contributing to variability in the six WBC traits, we utilized gene expression- and pathways-based analyses. We implemented gene-clustering algorithms to evaluate functional connectivity among implicated loci and showed functional relationships across cell types. Gene expression data from whole blood was utilized to show that significant biological consequences can be extracted from our genome-wide analyses, with effect estimates for significant loci from the meta-analyses being highly corellated with the proximal gene expression. In addition, collaborative efforts between the groups contributing to this study and related studies conducted by the COGENT and RIKEN groups allowed for the examination of effect homogeneity for genome-wide significant associations across populations of diverse ancestral backgrounds

Risk, ambiguity and the adoption of new technologies: experimental evidence from a developing economy

The slow adoption of innovations in less developed countries has long been a puzzle, given the high expected returns. This paper investigates the role of ambiguity-aversion as a fundamental behavioral determinant of technology adoption, motivated by the fact that, almost by definition, farmers have less certain information about the outcomes of new technologies compared with traditional technologies. Using primary data from field experiments used to measure behavioral parameters such as risk and ambiguity aversion, we find that farmers' aversion to ambiguity (but not risk aversion) limits the adoption of new technologies, even when expected profits are quite high. Interventions that reduce uncertainty (in place of interventions that reduce risk) seem a promising way of speeding up the adoption of innovations

Coordination and Strategic Behaviour in Landscape Auctions

Designing a conservation auction where bidders know the ecological value of their land poses challenges for policy makers because bidders will tend to increase their asking price. This is known as strategic behaviour, and it is particularly prevalent in sequential auction settings. The tender process ceases to be competitive when strategic behaviour occurs, eroding the efficiency advantages of an auction. To overcome this problem, contract options can be designed such that early winners are restricted in their efforts to strategically manipulate auction outcomes. Simply offering multi-period contracts could achieve this goal if participants need to wait for their contracts to expire before they can change their asking price. This idea was tested in a laboratory setting using computer software to simulate a simplistic multi-period auction for conservation. The results indicate that auctions offering multi-period contracts might be better equipped to constrain strategic behaviour compared to single period contracts. The treatment leads to a more efficient outcome, which supports the conclusion that given certain design intricacies, competition in an auction for conservation can be preserved with the provision of a system that works to ‘lock-in’ winners

Climate change and adaptation in Australian wheat dominant agriculture: a real options analysis

Australian crop and livestock farmers face uncertain climate change and variability and a challenge for adaptation decisions. These decisions can be (1) adjustments to practices and technologies, (2) changes to production systems, or (3) transformation of industries, for example, by relocation to new geographical areas. Adjustments to existing practices are easy to make, relative to changes to production systems or transformations at the industry level. Transformations require new investments and infrastructure and can leave assets stranded. These transformations can be partially or wholly irreversible and hysteresis effects can make switching difficult and mistakes costly to reverse. Real Options offers a framework to structure thinking and analysis of these difficult choices. This paper generalises and extends the principles of real options to capture the expected time until transformative thresholds are crossed. An application to South Australian wheat dominant agriculture is explored

Soil carbon sequestration in mixed farming landscapes: Insights from the Lachlan soil carbon project

The potential for soil carbon sequestration to play a significant role in meeting Australia’s greenhouse reduction targets has attracted widespread interest. Despite this interest, the economic scope for soil carbon sequestration remains poorly understood and the practical approaches that could be used to capture any opportunities have not been explored. In this paper we present preliminary results on a pilot soil carbon sequestration variable price, reverse tender auction in the mixed (wheat-sheep) farming system of the Lachlan Catchment, NSW. We draw on the results of the pilot to reveal; contract choice, landholders costs of soil carbon sequestration and the extent and impact of transaction costs associated with basic cost-effectiveness of the market mechanism

What are the barriers to adopting carbon farming practices?

In many environmental and conservation policy contexts, gaps are observed between policy objectives and implementation outcomes. Carbon farming policies are designed to mitigate greenhouse gas emissions, but policy success depends on the participation of land managers and their adoption of alternative land management practices. We surveyed Western Australian farmers to gauge their knowledge of carbon farming, their current adoption of carbon farming practices, and identified the drivers and barriers to adoption. Drivers for adoption included knowledge and perception of co-benefits (for yield, productivity, and the environment); beliefs and attitudes about climate change and its causes. Key barriers to the adopting carbon farming practices included policy and political uncertainty, and on-farm characteristics. We conclude that, to increase participation, the productivity benefits of carbon farming practices must be actively promoted and practices must be easy to integrate into existing farming systems