ABSTRACT. Various states take differing approaches to what is meant by the word sustainability. The proposed EU Space Act endorses sustainability as a core principle with a specific requirement that space operators calculate the environmental footprint across the mission lifecycle. The Australian Space Agency also places a strong focus on sustainability, as articulated in the UN Guidelines for the Long Term Sustainability of the Outer Space, the UN Space 2030 Agenda, and standards such as the European Cooperation for Space Standardization. But when we are talking about sustainability, are we all talking about the same thing? As part of the closer cooperation between Europe and Australia under the EU-Australia Free Trade Agreement and foreshadowed engagement with ESA, will we need to develop a clearer understanding of what we mean when we are talking about sustainability, and importantly, requiring operators to implement agreed standards across a joint mission. This presentation will identify the different approaches to sustainability in the space context, identify why this is important and interrogate the consequences of this for space activity.

ABSTRACT. The Australian Government’s Statement on Space identifies five focus areas where the nation can build competitive advantage and strengthen economic resilience: trusted space services, spaceflight ecosystem, space platforms, microgravity ecosystem and exploration technologies. While industry-focused, these areas also present significant opportunities for Australia's universities, research institutes and innovation ecosystem to contribute to outcomes of national and international importance.

In this keynote, the Head of the Australian Space Agency will highlight opportunities for Australian researchers to shape the next generation of space capabilities across the Statement's five focus areas. The presentation will explore how the Agency is supporting these opportunities through policy leadership, international partnerships, delivery of capability-building initiatives and sector engagement activities that help connect researchers with industry and international partners to deliver outcomes for Australia

ABSTRACT. The Minister for Defence and Space Industries will provide a broad overview of how South Australia is continuing to strengthen its position as Australia’s leading space state, highlighting the State’s strengths, emerging opportunities and the role of government in supporting investment, innovation and the continued growth of Australia’s space ecosystem.

ABSTRACT. Cells constantly adapt their morphology, adhesion, and migration in response to physical cues, processes that are fundamental not only to cancer progression but also to tissue development, repair, and immune function. In microgravity, the persistent gravitational force that shapes cellular mechanosensation on Earth is removed, leading to profound physiological alterations in astronauts, including impaired tissue maintenance and regeneration. Understanding how cells reorganize their behaviour under gravitational unloading is therefore critical for both space health and terrestrial medicine. Here, we leverage glioblastoma (GBM) as a model of extreme cellular plasticity to probe how complex morphogenic programs adapt in microgravity. We developed a tunable 3D hydrogel system based on hyaluronic acid and polyethylene glycol, with independently controlled adhesiveness, degradability, and stiffness, to recapitulate key mechanical and biochemical features of brain tissue while enabling precise interrogation of microgravity-induced responses. Under simulated microgravity, GBM invasion was markedly suppressed, particularly in degradable matrices, and cells underwent a pronounced phenotypic transition from mesenchymal, protrusiondriven migration to a cohesive, rounded state. Proteomic profiling revealed reinforcement of cell–matrix and cell–cell adhesion programs alongside redistribution of actomyosin contractility. Notably, CD44 expression increased under microgravity, consistent with an adhesion-driven adaptive response, while stemness markers such as Nestin and tumorsphere-forming capacity remained unchanged, indicating a selective, non-stemness adaptation. Mechanistically, integrin 1 and N-cadherin emerged as central regulators of this response, with their inhibition restoring dissemination exclusively under microgravity, thereby reversing the adhesive arrest. Together, these findings demonstrate that microgravity does not abolish motility per se but instead drives cells into an over-anchored, adhesion-dominated state that constrains migration. By integrating engineered ECM models with gravitational modulation, this work establishes a powerful framework to uncover mechanosensitive adaptation pathways relevant to cancer invasion, tissue morphogenesis, and cellular resilience in extreme environments, with direct implications for both astronaut health and disease modelling on Earth.

ABSTRACT. Bronchial epithelial cells (BEAS-2B) self-assemble into spheroids under simulated microgravity conditions. The spheroids are distinctly different to the cell aggregates formed under non-adherent gravity conditions. Mucin 1 (MUC1) is a membrane bound glycoprotein with a transmembrane subunit referred to as MUC1-C. MUC1-C plays a large role in cell signalling for proliferation, survival and attachment and interacts with EGFR and NF-kB. BEAS-2B cells were seeded as non-adherent cells in 1.7ml tubes and exposed to 3D clinostat simulated microgravity or gravity for 24 hours before the cells were lysed for RNA extraction. Compared to adherent conditions, PCR product band intensity revealed a significant increase of MUC1 in gravity conditions but not simulated microgravity conditions in BEAS-2B cells when normalised to GAPDH (p<0.05, n=6). Western blot showed similar changes in MUC1 abundance between adherent, gravity non-adherent, and simulated microgravity BEAS-2B cells. BEAS-2B cells were then treated with control, 1µM, 5µM or 10µM of MUC1-C inhibitor GO-203 and exposed to either gravity or 3D clinostat simulated microgravity. After 24 hours of GO-203 treatment, BEAS-2B cell aggregates under gravity conditions completely dissociated and attached to the non-adherent tubes. However, under simulated microgravity, the spheroids remained intact with minimal dose-dependent attachment. This suggests that simulated microgravity may reduce the dependence of BEAS-2B spheroid cohesion on MUC1-C. Both gravity and simulated microgravity spheroid formation were associated with increased CDH1 (E-cadherin) PCR product band intensity relative to adherent cells (p <0.0001, n=6). However, inhibiting MUC1-C in gravity resulted in complete dissociation despite CDH1 band intensity remaining greater than adherent cells. Simulated microgravity spheroids remained intact despite a reduction in CDH1 band intensity compared to non-treated simulated microgravity spheroids but still remained greater than adherent cells. This suggests that E-cadherin-associated cell-cell adhesion contributes to spheroid formation in gravity and simulated microgravity but is insufficient on its own to maintain spheroid integrity. Simulated microgravity may activate compensatory mechanisms that maintain spheroid structural integrity independent of MUC1-C and E-cadherin. Further mechanistic investigations are required to determine the compensatory mechanism.

ABSTRACT. Introduction: In space, altered gravity and weakened immunity increase infection risk, partly due to enhanced biofilm formation. Biofilms, bacterial communities in a protective matrix, are harder to treat than planktonic bacteria and are more resistant to antibiotics. As future space missions grow longer, novel antibiofilm strategies are urgently needed to preserve astronaut health and spacecraft integrity. Plasma-activated water (PAW), created by treating water with cold plasma to produce reactive species, has shown promise as an antibiotic-free and space-compatible antimicrobial. Hypothesis/Aim: We hypothesise that International Space Station (ISS)-derived isolates Enterobacter bugandensis (EB), Klebsiella pneumoniae (KP) and Staphylococcus haemolyticus (SH) are more tolerant of PAW in simulated microgravity compared to 1g static controls. Our aim was to quantify PAW antibiofilm activity against ISS-derived bacteria under simulated microgravity vs static controls. Method: Biofilms of EB, KP and SH were grown for 24h on a 2D clinostat to simulate microgravity (0 g) against static 1 g controls. Biofilms were exposed to PAW at pH 2.7 for 5 min. Antibiofilm activity was assessed by colony-forming unit counts and analysed by two-way ANOVA with Šídák’s multiple comparison tests (p<0.05). Results: PAW at pH 2.7 reduced all ISS-derived biofilms by 3-log10 under simulated microgravity and 4-log10 under static 1 g controls (p<0.01), indicating greater tolerance to PAW in simulated microgravity. Conclusion: While the antibiofilm activity of PAW in simulated microgravity was reduced compared to static controls, it still meets the 3-log10 industry benchmark for antimicrobials. These findings support PAW’s potential as a space-compatible antimicrobial for wound and surface decontamination, with room for further optimisation. It prioritises astronaut health for space missions, where medical standards on Earth may not survive the stressors of space.

ABSTRACT. Understanding radiation effects across the sub-cellular to human length scale is crucial to enabling space exploration and the establishment of sustainable human habitats beyond Earth. In particular, understanding the radiation environment experienced by microbes is essential to protecting astronaut health and supporting the production of food, pharmaceuticals, and other biologically derived resources in space. Many of the microorganisms required for these applications evolved under Earth's comparatively benign radiation environment, and their response to prolonged exposure in deep space remains incompletely understood. The development of a physics-based radiation transport model of the deep-space biological payload onboard the BioSentinel satellite using the OpenGATE/Geant4 Monte Carlo toolkit is presented. A digital twin of the satellite, hybrid radiation detector, and microbial experiment payload has been constructed to simulate the transport of energetic particles through the spacecraft and into the biological samples. Linear Energy Transfer (LET) measurements of incident protons within the liquid culture of the biological payload have been quantified and compared with measurements from the silicon hybrid radiation detector. Selected Galactic Cosmic Ray (GCR) particle species are targeted to further characterise the radiation environment experienced by the microbial payload. These simulations provide a foundation for correlating biological responses observed during spaceflight experiments with dosimetry measurements and for informing the design of future deep-space biological investigations.

ABSTRACT. A research focus of the ARC Centre of Excellence in Plants for Space (P4S) is to optimise plant growth in Outer Space for astronaut nutrition, research which can also have on-Earth applications such as facilitating plant growth in harsh environments or increasing yield. The knowledge gained from P4S experiments, supported by the use of synthetic biology, can be used to bolster on-Earth food security, and with it, national security. This paper highlights the security outcomes that are possible from Space-focused research.

Remote areas in Australia are impacted by food insecurity and as Freitag and Huling note, “Australia’s position as a globally competitive net food exporter could be creating a false sense of resilience.” A 2022-23 federal inquiry into food security in Australia highlighted this, an outcome of which is the on-going development of a National Food Security Strategy. This inquiry also recommended “innovation in food production” which the research of P4S arguably demonstrates.

This paper investigates the policy steps required to support the improvement of Australia’s food security, and with it, its national security, through the integration of synthetic biology progress, such as that implemented by P4S in experiments targeted for Outer Space. This includes analysis of the aforementioned strategy progress that is underway, as well as the Gene Technology Act 2000, the proposed Gene Technology Amendment Bill 2024 and FSANZ regulations. This research aims to outline how policy can best support the leveraging of Space-focused research, such as that of P4S, to improve Australia’s security.

ABSTRACT. During spaceflight, astronauts are separated from their partners, families, and friends, as well as their wider social networks and communities. This mixed-methods PhD project investigated the use of two types of technologies; virtual reality (VR) and voice-interfaced artificial intelligence (AI), for social connection in space and other isolated and confined environments such as Antarctica. The project consisted of a scoping review, which identified applications of VR for impacting mood and relaxation, emergency training, communication, as a testing environment, and exercise. No applications for AI to improve mood and wellbeing in this population were found. Secondly, a qualitative analysis of surveys from astronauts and interviews with people who had spent time in isolated and confined environments (ICEs) was conducted. This found a range of themes involving the types of relationships that were missed while in the ICE, crew selection, leadership, conflict, adaptive and maladaptive coping strategies, salutogenesis, and views about the use of VR and AI for social connection. Thirdly, the quantitative component of the project consisted of an experiment to induce loneliness in a general population sample, and test whether this was reduced through a VR interaction experience compared to a control condition. The experiment successfully increased loneliness; however the VR and control conditions were equally effective at reducing loneliness. Loneliness was not significantly associated with depression, anxiety, or coping styles, although different subtypes of loneliness (social, family, and romantic) were associated with higher state loneliness and stress, and lower relaxedness and happiness. Support for the link between loneliness and autonomic nervous system activation measured by heart rate variability, electrodermal activity, and salivary cortisol, was mixed. This project has implications for planning for psychological support and wellbeing for individuals on space missions, in isolated and confined environments, and in rural and remote environments.

ABSTRACT. The 2019-20 Australian Black Summer bushfires burned more than 110,000 km2 and resulted in economic losses exceeding AUD $7 billion. Climate projections indicate that the frequency and severity of extreme fire events are likely to increase, highlighting the need for improved early detection capabilities to reduce impacts on communities, infrastructure, and ecosystems.

State of the art bushfire detection systems rely on a layered architecture comprising ground-based fire towers, low-Earth orbit satellites, and geostationary satellites. The platforms present inherent trade-offs between spatial coverage, spatial resolution, and temporal resolution. Recent advances in High-Altitude Platform Stations (HAPS) present a unique opportunity to bridge this capability gap. Operating in the stratosphere for weeks to months with station-keeping capabilities, HAPS can provide persistent surveillance over large regions while achieving substantially higher spatial resolution than satellite systems. A network of stratospheric sensors could therefore deliver the high spatial and temporal fidelity required for early bushfire detection and rapid response . To investigate this capability, CSIRO has developed a lightweight multispectral imaging payload developed for early fire detection from the stratosphere. The payload combines a co-aligned long-wave infrared and RGB cameras with integrated positioning, navigation, timing, onboard storage, and autonomous fault-recovery capabilities. The instrument is designed to operate as a self-contained sensing system requiring only platform power while maintaining compatibility with a range of balloon and HAPS architectures.

In this talk, we will present an overview of the payload and data from stratospheric launch campaigns on light and heavy HAPS platforms, including example thermal imagery at a substantially higher spatial resolution than contemporary satellite observations. These results highlight the potential of low-cost stratospheric sensing networks to augment existing bushfire monitoring systems and support future operational early-warning capabilities.

ABSTRACT. The CSIRO Space Optics Team based in Adelaide develops custom optical instrumentation for Earth observation missions. This capability is demonstrated by CyanoSense, a compact hyperspectral imaging payload designed to detect potentially harmful algal blooms in inland water bodies. First launched in 2023, CyanoSense combines a custom 500–810 nm optical system with onboard computing for Level 1 top-of-atmosphere radiance processing within a 4 kg, 300 × 150 × 150 mm payload. With CyanoSense 2.1 scheduled for launch in the first quarter of 2027, the programme provides flight heritage for CSIRO’s approach to the design and delivery of compact optical payloads. This paper presents the extension of this capability to a substantially larger aperture through the design and structural optimisation of a 300 mm aperture, f/8 telescope for Earth observation. The work applies an integrated optical-mechanical design process in which optical performance, structural stiffness, mirror lightweighting and mounting-induced deformation are considered concurrently. The optical design achieves a predicted wavefront error of less than 10 nm RMS on-axis and less than 39 nm RMS at the edge of the field. A finite-element-driven parametric optimisation of the lightweighted primary mirror demonstrates compliance with an allocated surface figure error of 11.2 nm RMS, while reducing mass and maintaining the stiffness required for launch and operational environments. The primary mirror is supported by a three-bipod flexure mounting system designed to minimise surface deformation arising from assembly, thermal loading and structural constraint. The structural model predicts a first mode above 200 Hz, providing approximately 20% margin against the project requirement. The telescope targets a modulation transfer function greater than 0.3 at half the detector Nyquist frequency for a 3.45 µm pixel pitch. At a nominal orbital altitude of 530 km, the resulting ground sampling distance is approximately 0.76 m. By the time of the conference, the secondary mirror will have been manufactured and the laboratory’s optical metrology capability expanded to support the characterisation of optics at this aperture scale. The paper will present the design methodology, optimisation process and predicted structural and optical performance of the telescope, together with progress towards manufacture and experimental validation. The work demonstrates CSIRO’s ability to scale its optical system engineering approach from compact flight payloads to larger aperture instruments, with the underlying design and optimisation methods also applicable to Space Domain Awareness and Space Situational Awareness systems.

ABSTRACT. The increasing frequency of space launch activities has raised growing concerns regarding their potential effects on ecosystems surrounding launch facilities. Rocket launches can generate thermal emissions, atmospheric pollutants, and localized environmental changes, potentially affecting vegetation, land surface conditions, air quality, and surrounding land-use patterns. Assessing these impacts is particularly important for launch facilities located within or adjacent to environmentally sensitive coastal landscapes. This study evaluates the environmental impact susceptibility associated with space launch activities at the Satish Dhawan Space Centre (SDSC-SHAR), Sriharikota, Andhra Pradesh, India. Sriharikota is a barrier island characterized by coastal vegetation, wetlands, water bodies, and other ecologically sensitive landforms. Multi-source datasets from Landsat 8/9, Sentinel-2, Sentinel-5P were used to derive thematic layers representing Land Surface Temperature (LST), Normalized Difference Vegetation Index (NDVI), atmospheric pollutants including nitrogen dioxide (NO₂) and carbon monoxide (CO), Land Use/Land Cover (LULC). A weighted overlay approach was subsequently applied to generate an Environmental Impact Susceptibility Index (EISI), classifying the study area into low, moderate, high, and very high susceptibility zones. This study evaluated the environmental impacts of rocket launch activities at Sriharikota using GIS, Remote Sensing, and MCDA techniques. Pre- and post-launch changes were analyzed using NDVI, LST, NO₂, CO, LULC, and wind data for selected launch events. The results showed increased atmospheric pollution and thermal effects near the launch influence zones, while vegetation and coastal ecosystems showed varying levels of susceptibility. The MCDA-based susceptibility model successfully identified high-impact and vulnerable regions across the island, highlighting the importance of environmental monitoring for sustainable space operations.

ABSTRACT. Majority of the world's orbital assets are located in the Low Earth Orbit (LEO), sharing this volume of space with a substantial proportion of space debris. The most numerous and concerning of this debris lies within the size range of 1-10 cm which is difficult to routinely detect, track and catalogue, yet carries sufficient kinetic energy to be catastrophic for satellites and human space missions. Active Debris Removal (ADR) through ground-based laser or orbital capture methods using satellites requires a very high level of precision in the orbital elements of the debris which is difficult to achieve using conventional single-point optical or radar detection and tracking methods. A concerted sequence of optical detection, tracing, and tracking of small space debris in LEO simultaneously from multiple sites through triangulation, facilitated by machine learning algorithms, will generate a level of precision in the orbital parameters of the debris which may enable its tackling (ADR). This sequence is achievable through the use of a synchronized network of medium-aperture short-focal ratio telescopes with wide field of view for detection and tracing of uncatalogued debris, and long focal-ratio telescopes of high magnification for tracking of this debris. Mounted on mobile platforms or observatories for rapid transit and deployment across a vast area, these telescopes can be synchronized through a central server aided by low latency communication protocols and machine learning algorithms. This constitutes the basic architecture of our patented incremental detection refinement protocol - the Trace, Track and Tackle sequence of debris detection and mitigation. Deployed across the vast Australian outback, such a network will be able to detect and track LEO debris between 12 and 18 magnitudes of brightness, corresponding to 1-10 cm debris in LEO between 500 to 2,000 km orbital altitude. The machine learning pipeline for detecting, tracking, and classifying potential space debris combines a Real-Time Detection Transformer (RT-DETR) and a Linear Kalman Filter (LKF), which will together harness the rapid detection capabilities of RT-DETR and the predictive power of the LKF.

ABSTRACT. Project Swift is a University of Southern Queensland small-satellite mission being developed to demonstrate precision optical astronomy and remote sensing from a cost-constrained spacecraft platform. The mission comprises a ~60 kg-class, two-payload satellite planned for a nominal ~550 km Sun-Synchronous Orbit, with a primary 20 cm optical imaging system based on HEO’s Adler design. The project combines spacecraft pointing and thermal-control development with astronomical observations aimed at improving the characterisation of exoplanet candidates identified by NASA’s Transiting Exoplanet Survey Satellite (TESS) Follow-up Program. Particular emphasis is placed on high-cadence, high-precision photometry of selected targets to confirm transit signals and refine their timing and photometric parameters. Current development and comfirmed flight model plans include an improved detector and associated optical and computational systems, while longer-term, laboratory-based, investigations include ultraviolet detector technologies, axial thermal expansion negation, and the potential application of the platform architecture to observations from geostationary orbit. Project Swift therefore provides both a scientific program for small-satellite exoplanet observations and a technology-development pathway toward future sovereign Australian space-based astronomical and remote-sensing capabilities.

ABSTRACT. There is increasing interest in space domain awareness (SDA) worldwide, motivating the use of non-traditional sensors for space surveillance. One such sensor is the Buckland Park Stratosphere-Troposphere VHF radar, which has demonstrated an ability to detect over 2000 resident space objects (RSOs) daily. A by-product of these observations is the measurement of ionospheric group retardation, which can be used to measure the total electron content (TEC) between the ground and the satellite altitude. This paper describes Buckland Park VHF radar vertical TEC (vTEC) observations of Starlink satellites. The vast number of Starlink satellites and the public availability of precise ephemerides allow vTEC measurements to be made from the ground to 490 and to 560 km at one minute resolution and 0.2 TEC units (TECU) accuracy. These measurements allow estimation of the relative ionospheric and plasmaspheric components of Global Navigation Satellite System (GNSS) estimated TEC. The measurement of these components compares favourably with those measured using other techniques, including ionosonde and radio occultation measurements.

ABSTRACT. The emergence and evolution of solar active regions are fundamental to understanding and predicting space weather. Surface motions of magnetic flux can drive magnetic reconnection and the release of energy associated with flares and coronal mass ejections. Recent observations suggest that near-surface convection influences active-region emergence, and any theory of flux emergence must account for the statistical tilt of active regions described by Joy's law. To investigate the role of convection in the orientation of active-region magnetic fields, we examine the relationship between emerging magnetic flux and near-surface supergranulation flows in 130 active regions. The mean tilt of regions following Joy's law increased from $5\pm1^\circ$ to $12\pm1^\circ$ during emergence, while anti-Joy regions remained approximately constant at $-4\pm3^\circ$. Averaged flow maps show that north-south flows associated with the leading polarity are consistent with its direction of motion: equatorward flows correspond to positive tilt and poleward flows to negative tilt. These flows have amplitudes of $\sim50\,\mathrm{m\,s^{-1}}$ and spatial scales of $\sim25$ Mm, comparable to those of supergranules with asymmetric north--south flows. We propose that the location of active-region emergence within the supergranulation pattern influences the sign of the tilt angle, and like the Coriolis force causes vortical flows such as hurricanes on Earth, the vortical flows induced by the Coriolis force in supergranules contributes to the statistical tendency described by Joy's law. These results demonstrate that near-surface convection plays an important role in organizing emerging magnetic flux and should be considered in physics-based approaches to space-weather forecasting.

ABSTRACT. The March 13, 1989, geomagnetic storm caused a blackout in Québec, and the October 29, 2003, storm caused a blackout in southern Sweden. These events reached storm-time disturbance (Dst) minima of −589 nT and −383 nT, respectively. More recently, the May 10–13, 2024, storm was the most intense since 1989, with a minimum Dst of −412 nT. To better understand geomagnetic storm hazards, we analyse 1–20 s resolution ground magnetometer data from three Northern Hemisphere high latitude arrays: the International Monitor for Auroral Geomagnetic Effects (IMAGE), the DTU Space Greenland network, and the Canadian Array for Realtime Investigations of Magnetic Activity (CARISMA). For each event, we compute normalized wavelet power spectra and scale-averaged power across physics-based period bands, enabling comparison across storms and stations spanning geomagnetic latitudes of ~54°–85°N.

We find spectral power maxima coincide with Dst minima. As storm intensity increases, dominant power shifts equatorward, consistent with expansion of the auroral electrojet. During quiet conditions and after storm recovery, high latitude stations have the most magnetic power. As a geomagnetic storm progresses, the range in magnetic power across all stations decreases from ~3 orders of magnitude during quiet times to one order near storm peak. These results provide a framework for anticipating the latitude dependence of geomagnetic impacts during severe space weather.

Building on this framework, we extend the analysis to geoelectric hazards, assessing the role of local subsurface electrical conductivity. We are developing a cross-hemisphere comparison of storm-time geoelectric fields along Australia's Adelaide–Brisbane corridor (AusLAMP, ~20 million people) and the U.S. Northeast Corridor (USArray, ~53 million people). Magnetotelluric impedance tensors are convolved with geomagnetic observatory data from Solar Cycles 24–25 across physics-based period bands. This work will quantify how geomagnetic latitude, local time, and three-dimensional conductivity structure jointly modulate geoelectric hazards.

ABSTRACT. The May 2024 geomagnetic storm was the largest storm since November 2003. Widespread interruptions of Global Navigation Satellite System (GNSS) applications were reported on the internet at the time, and more recently in scientific peer-reviewed papers that investigated the event. Some reports revealed that Precise Point Positioning (PPP) – a technique that uses a single GNSS receiver to achieve cm-level accuracy – was significantly impacted across Australia in particular. This study focuses on the ionospheric variability across the Australian sector, seeking explanations for the large-scale, regional-scale and small-scale (i.e., plasma waves/turbulence) ionospheric plasma dynamics that were observed during the storm. Our analysis identifies a regional ionospheric feature that is remarkably similar to the “Nighttime Ionospheric Localised Enhancement (NILE)” feature reported over the United States during the more intense November 2003 storm. During the May 2024 storm, this “NILE” feature was accompanied by small-scale plasma turbulence that we posit was the cause of the PPP disruption across Australia. The present study uses a combination of observations and modelling to explore the physical mechanisms responsible for the generation of small-scale plasma waves across Australia during the storm, and in the process, highlights some shortcomings in the theoretical frameworks that describe middle latitude plasma turbulence.

ABSTRACT. The ionosphere is a dynamic region of the upper atmosphere where electron density varies over a range of spatial and temporal scales. Its behaviour is governed by many processes including latitude-dependent electrodynamics, and responses to solar and geomagnetic activity. During geomagnetic storms, the ionosphere becomes highly disturbed, affecting radio-wave propagation and satellite-based navigation systems. The May 2024 geomagnetic superstorm provided an opportunity to study the response of the Australian ionosphere to extreme space weather. This is of particular importance in low-latitude regions of Australia, where the more turbulent ionosphere can severely degrade Global Navigation Satellite System (GNSS) performance through enhanced total electron content (TEC) variability and ionospheric scintillation. This event not only provides insight into ionospheric behaviour but also enables the reliability of communication systems reliant on radio signal propagation to be assessed under such conditions and considered in the context of real-world applications. For example, Ground-Based Augmentation Systems (GBAS) located at airports both in Australia and globally, facilitate precision landing by providing real-time corrections to approaching aircraft. During periods of increased geomagnetic activity these systems can become compromised. This research aims to understand and mitigate the potential effects of future storms, while also addressing the limited research focus on the Australian ionosphere. In this study, we investigate the low-latitude ionospheric characteristics during this extreme geomagnetic event using GNSS data from northern Australia. The variation of TEC, ionospheric delays and gradients, and amplitude scintillation is examined, in addition to the physical mechanisms driving these behaviours. The relationship between TEC and scintillation in this region is also explored. The potential impacts with, a focus on GBAS used at low-latitude airports, will be discussed.

ABSTRACT. The largest non-conservative perturbing force that Low Earth Orbit (LEO) satellites are subjected to is atmospheric drag caused by thermospheric density. When thermospheric density changes unexpectedly, satellite orbits can deviate from their predicted trajectories, which is especially concerning for the more densely populated LEO regime. Some of the more severe variations in thermospheric density are the result of geomagnetic storms. Of particular note are intense, localised enhancements, or spikes, at high latitudes that have been observed to reach up to ~700% of quiet-time density. In this work, density spikes were identified within the Swarm C accelerometer-derived neutral density data for 44 geomagnetic storms across the Swarm C satellite lifetime. Spike intensities and their locations over polar magnetic latitudes are investigated. Results show that the peak density of a high latitude density spike is typically larger for more intense geomagnetic conditions as defined by the SYMmetric H-component (SYM-H) index. However, this correlation was not shown for more intense geomagnetic conditions as defined by the Polar Cap (PC) indices, a better proxy that describes the solar wind-magnetosphere coupling. In the past, density spikes have shown alignment with Joule heating sources in either polar or auroral regions for a single storm; however, statistical analysis of many density spikes in this study does not show a clear separation into these regions. The results therefore highlight the need for further research and in-depth analyses of the generation of these high-latitude density enhancements. In doing so, it would be possible to predict not only the more intense spikes in larger geomagnetic storms, but also their locations based on the generation mechanisms with which they are associated. With the ability to accurately predict high latitude density enhancements, their impact on satellite orbits can be forecast and mitigated.

ABSTRACT. In this study, we describe changes in ionospheric parameters, including the critical frequency of the F2 layer (foF2), the height of the peak electron density in the F2 layer (hmF2), total electron content (TEC), and neutral densities (ND), observed using ionosondes, COSMIC-2, SWARM satellites, and riometers during the May 2024 G5 geomagnetic storm. This storm, the most powerful in over 20 years, was classified as G5, with a maximum Kp index of 9 and Dst index reaching -412 nT.

Each observing system has its strengths and weaknesses, being sensitive to different aspects of the ionosphere. Ionospheric parameters scaled from ionograms are generally considered most reliable when manually scaled. COSMIC-2 TEC observations may exhibit biases when using transmissions from different satellite constellations (e.g., GPS vs. GLONASS). Potential onboard calibration errors in SWARM accelerometers could affect neutral density observations, and riometer data are sensitive to local weather and interference from ground-based HF networks. Despite these inherent differences and weaknesses, collectively, these observations provide a more comprehensive understanding of the ionosphere's physical properties compared to using a single observing system.

In this paper, we present several features of the May storm that were consistent with ionospheric storm behaviour as well as atypical observations. Negative ionospheric storms (depleted foF2) occurred almost instantaneously at high latitudes in both hemispheres. hmF2 immediately increased in low and mid-latitude regions, and ND significantly increased soon after the storm's onset. High-latitude D-region electron density enhancements persisted for several hours post-storm onset. Notably, the most perplexing yet consistent feature observed across all observing systems was the enhanced neutral and electron densities, along with increased hmF2, in the Southern Hemisphere. The electron density enhancements were delayed, occurring during the subsequent night following the storm's sudden commencement in the Southern Hemisphere, whilst they were completely absent in the Northern Hemisphere.

ABSTRACT. Lunar governance depends on coordination, yet states cannot coordinate around conflicts they cannot see. Current discussions treat resources as discrete categories: extractable, spatial, environmental, intangible, electromagnetic. But interference happens at the overlaps. A landing site may sit inside a radio-quiet zone. A stable orbit may cross an extraction corridor. This paper proposes a constraint mapping framework that overlays all resource categories on a single spatial reference, making overlaps visible and consultation possible.

Article IX's due regard standard, informed by ICJ jurisprudence, requires consultation where harmful interference is possible. The map establishes the factual basis for that trigger. It supports Article VI, giving states a technical basis for supervising operators. It does not depend on Article XI's voluntary disclosure. The map is public by necessity: practice that cannot be seen cannot become the basis for interpretation.

The map makes responsible behaviour visible and irresponsible behaviour harder to defend.

ABSTRACT. Pacific Island Nations (PINs) face a complex and evolving security environment shaped by climate change, maritime governance challenges, geographic isolation, and increasing geopolitical competition. While space capabilities are often associated with major powers, Pacific states are increasingly engaging with space-enabled technologies to address pressing human, environmental, and national security concerns. This paper examines the evolution of space activities across the Pacific and explores how PINs access, adopt, and govern space-based capabilities. Drawing on government policy documents, regional strategies, and open-source analysis, the study identifies seven principal areas of space engagement: Earth observation, maritime domain awareness, communications, orbital slot governance, launch activities, astronomy and astro-tourism, and education and capacity development. The analysis demonstrates that space activities in the Pacific are largely enabled through external partnerships rather than sovereign capability, creating both opportunities and dependencies. The paper argues that strategic hedging provides a useful explanatory framework for understanding Pacific engagement with space. Rather than aligning exclusively with a single external actor, many PINs pursue diversified and issue-specific partnerships with countries including Australia, the United States, the United Kingdom, New Zealand, South Korea, and increasingly China. Through initiatives such as Digital Earth Pacific, regional maritime surveillance arrangements, and the adoption of satellite communications networks, Pacific states seek to maximise access to critical capabilities while preserving autonomy and reducing strategic vulnerability. The findings suggest that space-based capabilities are becoming increasingly important instruments of climate security, maritime governance, and economic resilience in the Pacific. However, fragmented implementation, limited institutional capacity, and continued dependence on foreign providers constrain their long-term effectiveness. The paper concludes that regional ownership, workforce development, and diversified partnerships will be essential if space technologies are to contribute meaningfully to Pacific security and resilience while supporting the strategic autonomy of Pacific Island Nations.

ABSTRACT. The rapid expansion of global space activities over the past decade has contributed to a significant increase in orbital debris, raising concerns about the long‑term sustainability of Earth orbit. In 2025, the Australian Space Agency (the Agency) became an associate member of the Inter‑Agency Space Debris Coordination Committee (IADC), the principal international forum for technical cooperation on space debris. This development provides a useful context for examining how national space debris research relates to international debris‑mitigation efforts, highlighting the opportunity to align national debris-mitigation activities with international initiatives and standards.

To support evidence-based engagement, the Agency issued an invitation for Expressions of Interest, requesting information on existing space debris research and capabilities relevant to the IADC working groups, as well as interest in joining an Australian space debris research community. The aim of the EOI was to identify patterns of strength in the Australian space debris ecosystem.

Despite growing interest in sustainability within the space sector, there has been no systematic review of Australian space‑debris research and how it aligns with the IADC’s technical working groups. Existing discussions tend to focus on individual projects or institutional capabilities, leaving limited understanding of the broader research ecosystem. To address this gap, this work undertakes a mapping of Australian space‑debris research activities to the four IADC working groups (WGs) based on the information received in the EOI responses and a literature review.

This capability mapping demonstrates how such an approach can enhance international collaboration, reduce duplication of effort across research communities, and identify opportunities for future research. Together, these outcomes support more informed engagement in multilateral technical forums and contribute to a more cohesive global approach to space debris sustainability.

ABSTRACT. International space debris governance remains grounded in a liability framework designed for a state-centric space regime. Under Article VI of the Outer Space Treaty 1967, States retain international responsibility for national space activities, including those conducted by non-governmental entities, while Article VII, read with the Liability Convention 1972, establishes international liability of the launching State for damage irrespective of the entity operating the space object. Although domestic legal regimes may allocate financial and insurance obligations to private operators, the international liability architecture remains principally state-centred. However, developments in Space Situational Awareness and Space Domain Awareness enable sophisticated debris tracking, collision avoidance, and controlled re-entry in ways that were not previously possible, challenging the aforementioned framework. International law has not kept pace with these developments and remains predominantly focused on ex-post liability rather than ex-ante prevention. This approach is increasingly misaligned with the technological and commercial realities of contemporary space activity.

Domestic practices highlight this gap. For instance, India’s Planned Re-Entry Guidelines, 2026, reallocate financial liability to private players through mandatory insurance and no-fault indemnification. Recent debris-recovery incidents in Australia involving foreign-launched space objects further demonstrate the practical challenges of identifying, attributing, and allocating responsibility for debris that crosses national jurisdictions. With the advent of commercial mega-constellations accelerating orbital congestion, such incidents jeopardise legal certainty and long-term sustainability.

This paper highlights the need to shift from liability-based governance to preventive, operator-oriented governance and probes into how SSA or SDA capabilities can be integrated harmoniously into debris regulation, while placing meaningful obligations on actors capable of preventing debris harm.

ABSTRACT. Australia's regulatory framework for space activities was built for an era of infrequent launches. It is now being tested by a fast-growing commercial sector, rapidly evolving technology, and increasing strategic reliance on space-derived capability.

WRegSAT is an independent, interdisciplinary research initiative, led by the Australasian Centre for Space Governance in partnership with UNSW Canberra, that brings together law, engineering, policy, industry and civil society expertise to examine how Australia's regulatory framework must evolve. Each annual series convenes three expert workshops around a focused regulatory challenge and produces a Regulatory Options Paper for government and industry.

Series I conducted a comprehensive survey of the regulatory landscape, from launch and ground infrastructure to spectrum, orbital operations, deep space, accidents and liability, and national security. Its Foundations Paper — framed by the Worimi concept of maa bullarbu, thinking seven generations ahead — identifies recurring themes including regulatory fragmentation, the absence of a national space strategy, weak sustainability enforcement, and the strategic value of Indigenous governance frameworks.

Series II, which launched in April 2026, turns to near-future in-orbit activities: debris removal, servicing, proximity operations, space traffic coordination, and more.

WRegSAT actively seeks engagement from Australia's space research community. This session introduces the initiative, its Series I findings, and pathways to contribute.

ABSTRACT. The Australian government is exposed to a range of contingent liabilities arising from space activities attributable to Australia - under a variety of international laws, under transnational arrangements such as cross-waivers and contractual indemnities, and under domestic statutory and general law — including for activities conducted by private operators under government authorisation and continuing supervision. As Australian space activity increases in both volume and character, shifting toward in-orbit operations such as rendezvous, proximity operations and servicing, this exposure grows. Yet Australia's regulatory framework concentrates risk mitigation at the launch and return phases, leaving the operational in-orbit phase, where the exposure now grows fastest, largely unregulated and unquantified.

This paper develops an ontology of the Commonwealth's liability exposure across international, transnational and domestic law, distinguishing exposures by fault standard, by whether they are capped, and by whether they are presently quantified. It argues that the most effective mitigation is not a liability cap but a regulatory capability and architecture that reduces the probability of the liability-triggering event and generates the evidence to defend against claims, thereby also discharging Australia's Article VI supervision obligation. Framed against the benefits of participation and Australia's space dependency, disciplined liability management is the price, and the enabler, of leaning into the sector.

ABSTRACT. Sporadic-E (Es) layers form through wind-shear convergence of long-lived metallic ions and are strongly influenced by atmospheric tides and planetary waves propagating upward from the middle atmosphere. Although these waves modulate Es occurrence, the relative importance of lower-atmospheric variability versus space-weather forcing remains poorly quantified over the Southern Hemisphere.

Using a six-station meridional (12–43°S) and five-station zonal (114–190°E) ionosonde network across Australia and the southwest Pacific, we analysed over one million ionograms from 2015–2024. An automated ridge-tracking algorithm extracted Es critical frequency, layer height, and F-region parameters from every sounding. Planetary-wave activity (2–16-day bands) was quantified by robust spectral analysis; zonal propagation was estimated using phase-randomised beamforming with Monte Carlo significance testing; and relationships with El Niño–Southern Oscillation (ENSO), solar flux (F10.7), and geomagnetic activity were assessed via cluster-bootstrap mixed-effects regression.

No significant ENSO dependence of Es planetary-wave amplitude was found, corroborated by occurrence analyses showing no consistent El Niño enhancement. In contrast, wave amplitude correlates strongly and inversely with solar flux, while coherence, zonal wavenumber, and phase speed show no significant solar dependence — indicating that rising solar flux suppresses Es wave amplitude without altering its propagation. Beamforming identifies a persistent westward quasi-16-day mode coherent across the sector in all ENSO phases, whereas shorter periods are less spatially coherent.

Solar-cycle variability, not tropical climate variability, is thus the dominant external control on Australian Es planetary-wave activity — arguing for solar flux as a primary predictor in operational Es forecasting supporting HF communications and over-the-horizon radar.

ABSTRACT. Since September 1993, the Super Dual Auroral Radar Network (SuperDARN) radars have measured high-latitude ionospheric plasma flows by exploiting scatter from irregularities embedded in the plasma as tracers of the bulk motion. It is reasonable to assert that most of our understanding of polar ionospheric plasma dynamics is based on SuperDARN products; these include the spatial distributions of echo intensity, Doppler shift and Doppler spread. By combining line-of-sight Doppler velocity measurements from multiple radars, together with physical models of coupling between different levels of the ionosphere via the geometry of the geomagnetic field, the two poleward-looking networks assemble maps of the large-scale polar plasma circulation driven by the solar wind. It would seem obvious that the sources of the irregularities would have been the subject of detailed investigation, and this has indeed been the case. Several plasma instabilities have been found to account for the rapidly-evolving irregularities, with the modified two-stream (Farley-Buneman) instability predominantly responsible for the metre-scale structures generated in the E region, the gradient-drift instability operating throughout the ionosphere, and the modified Rayleigh-Taylor and Kelvin-Helmholtz instabilities active near the cusp boundaries. While much is known about these phenomena, the picture is not fully resolved. It would seem equally likely that the scattering mechanism responsible for SuperDARN radar echoes would have been resolved unambiguously, but an examination of the literature suggests that, once the primary mechanism had been established, more detailed assessments have not been reported. In this paper we explore a natural refinement to the standard model and estimate its significance. The mechanism we consider is a double-scattering process, motivated by observation of double-peaked structure in two examples of ionospheric clutter spectra, one recorded by an Australian HF radar observing the equatorial electrojet and one from a Canadian SuperDARN. An analogy is drawn between the present context and HF scatter from the ocean surface, where the second-order scatter signature supports detailed measurements of the directional wave spectrum. We conclude that the mechanism can impact the SuperDARN radar observations, but in a subtle way that fails to deliver the kind of environmental information retrievable from ocean spectra.

ABSTRACT. This study presents the development and verification of AUSTEC, a regional model for reconstructing and mapping Total Electron Content (TEC) over the Australasian region. AUSTEC employs Empirical Orthogonal Function (EOF) analysis to decompose historical TEC datasets into dominant spatial modes and associated temporal coefficients, providing an efficient low-dimensional representation of ionospheric variability. The model uses a two-layer decomposition in which historical TEC maps are separated into a mean field and leading EOFs, while the corresponding temporal coefficients are modelled using solar and geomagnetic activity indices, seasonal harmonics, and diurnal patterns. In operation, pre-computed EOF patterns are combined with real-time observations to generate hourly regional TEC maps. Model verification was conducted during March and April 2023 using NASA JPL Global Ionospheric Maps (GIMs) and comparisons with the Bureau's operational IRI-2020-based framework in both storm-on and storm-off configurations under quiet and disturbed geomagnetic conditions. The results demonstrate good agreement between AUSTEC, and the JPL TEC maps during geomagnetically quiet periods, accurately reproducing regional TEC magnitudes, spatial gradients, and day-to-day variability. AUSTEC also outperforms both IRI-2020 configurations during quiet conditions, particularly in representing low-latitude TEC. During geomagnetic disturbances, performance decreases across all models, reflecting the challenge of representing the magnitude and complexity of storm-time ionospheric variability. While AUSTEC maintains a realistic background TEC structure, it shows limited sensitivity to rapid storm-time changes; the IRI storm-off configuration exhibits no storm response, while the storm-on option captures only a partial and latitude-dependent disturbance signature. Nevertheless, the EOF-based framework provides a computationally efficient and flexible architecture, which supports future enhancements through the incorporation of higher-frequency geomagnetic inputs, additional ionospheric drivers, machine-learning-based storm-time modelling, and improved spatial and temporal resolution.

ABSTRACT. The ionosphere is regularly considered Earth’s window into space. Our ability to characterise and forecast the conditions in the ionosphere impacts space-based applications such as Global Navigation Satellite Systems (GNSS). Other impacts include changes to High Frequency (HF) wave propagation affecting surveillance and communications, such as those used during disaster recovery efforts. Predicting these impacts involves understanding the plasma dynamics in the ionosphere which are driven in part by the solar wind and associated Interplanetary Magnetic Field (IMF), particularly in the high-latitude regions. Empirical models of the high-latitude ionosphere provide boundary conditions for physics-based models that simulate the ionosphere-thermosphere system. These simulations use numerical methods which are sensitive to boundary conditions. Additionally, these empirical models are used independent of the variability of the ionosphere-magnetosphere-solar wind system, and provide a statistically averaged state, even when the system is in a transient state. The high-latitude ionosphere is commonly assumed to require 20-30 minutes of quasi-stable IMF conditions to reach a quasi-stable ionospheric configuration. The high-latitude convection pattern and Birkeland field-aligned currents are well characterised and explained for all orientations of IMF. However, the characterisation of these quasi-stable configurations is based on static definitions of IMF conditions. Previous discretisation of IMF conditions paved a pathway into understanding the impact of IMF orientation and strength on the high-latitude dynamics. However, exploring dynamic definitions and characterising transient events is the next stage in characterising ionospheric configurations. This work presents a quantitative statistical evaluation of a static vs variable characterisation of IMF stability. Case studies are presented to investigate the ionospheric configuration for IMF conditions that span two different states in the static discretisation of IMF conditions. Additionally, the concept of a varying ionospheric relaxation time is discussed, based on the type of transient period preceding the quasi-stable IMF event.

ABSTRACT. Transient disturbances near the dayside magnetopause play a key role in transferring energy and momentum from the solar wind into Earth’s magnetosphere. These disturbances, driven by processes such as solar wind pressure variations, transient magnetic reconnection, and Kelvin–Helmholtz (KH) instability, are expected to weaken as they propagate away from the magnetopause. In this study, we investigate the spatial decay of magnetopause transient signatures with increasing distance from the boundary using a combined observational, theoretical, and modeling approach. Multi-point magnetic field measurements from the THEMIS (Time History of Events and Macroscale Interactions during Substorms) mission on 31 July 2007 are analyzed. The five THEMIS spacecraft (A–E) provided coordinated observations across radial distances of approximately 6–10 R_E, enabling direct examination of the spatial structure of magnetic perturbations. The results show coherent fluctuations in the north–south magnetic field component (Bz) whose amplitudes generally decrease with increasing distance from the magnetopause, indicating strong spatial damping of the wave activity. These observations are compared with theoretical predictions for surface wave propagation, in which KH-driven perturbations exhibit exponential attenuation away from the boundary due to evanescent behavior in the magnetospheric plasma. The measured decay rates are in good agreement with theoretical expectations. Complementary global magnetohydrodynamic (MHD) simulations reproduce the observed radial trends, confirming that large-scale magnetopause perturbations can account for the measured spatial decay. Overall, this study demonstrates that the decay rate of magnetic fluctuations is a robust diagnostic of boundary-driven processes and highlights the importance of multi-point observations for understanding solar wind–magnetosphere coupling.

ABSTRACT. We present the discovery of a flare-driven coronal kink wave directly associated with the generation of a seismically weak sunquake during the M7.7 flare of 30 September 2024 in NOAA Active Region 13842. Combining helioseismic holography from SDO/HMI with the unique stereoscopic perspectives provided by Solar Orbiter/PHI and EUI, we identify a compact acoustic source confined to the 4–6 mHz frequency band and spatially coincident with the flare footpoint. Although the acoustic energy is modest, the observations provide an unprecedented view of the coronal magnetic dynamics preceding and driving the seismic response. High-cadence, unsaturated EUI observations reveal a transversely oscillating magnetic strand—a coronal kink wave with a period of approximately 68 s—anchored directly above the seismic source immediately before the flare impulsive phase. The estimated energy of the kink wave is comparable to the acoustic energy, whereas the available Lorentz-force work exceeds both by two to three orders of magnitude, strongly supporting rapid magnetic restructuring as the driver of the sunquake. These observations provide the first stereoscopic evidence linking a coronal kink wave, magnetic back reaction and flare-driven seismic emission, establishing a direct observational connection between coronal MHD wave dynamics and acoustic energy deposition into the solar interior.

ABSTRACT. Accurate modelling of the ionosphere-thermosphere system is essential for space weather forecasting and satellite operations, particularly through reliable estimates of thermospheric neutral density. However, physics-based models such as the Global Ionosphere Thermosphere Model (GITM) contain uncertain chemical and physical parameters that affect model sensitivity to solar activity changes and geomagnetic disturbances. This study presents progress toward a Supertuned-GITM by constraining key nitric oxide (NO) reaction rates and NO vibrational relaxation rates using Bayesian optimisation techniques. Building on from earlier sensitivity analysis that identified the most influential NO chemistry parameters, we developed a Bayesian inversion framework that estimates optimal reaction-rate values by combining GITM outputs with satellite observations, incorporating neutral density measurement from Swarm satellite and TIMED/SABER NO radiance emission measurements. A Gaussian Process Regression (GPR) based surrogate model is used to represent the nonlinear relationships between the uncertain reaction-rate parameters and GITM outputs, including thermospheric neutral density and NO radiance. This approach substantially reduces the computational cost of estimating observation likelihoods compared with full GITM simulations. This allows us to use Bayesian inference via Markov chain Monte Carlo (MCMC) integral evaluation to learn the posterior densities of the uncertain NO chemistry parameters. Large simulation ensembles were run with perturbed reaction-rate coefficients for quiet, storm, and recovery phases under both solar minimum and solar maximum conditions to generate the training and test datasets required for surrogate modelling. The performance of Supertuned-GITM with optimised reaction rates is assessed against standard GITM and satellite observations. This comparison characterises the sensitivity of simulated neutral density and NO radiance to the constrained NO chemistry and demonstrates the applicability of surrogate-based Bayesian inversion for parameter estimation in physics-based thermospheric models.

ABSTRACT. Ole Rømer’s 1676 interpretation of variations in the eclipse timings of Jupiter’s moon Io offers a particularly valuable example, linking planetary geometry with the finite travel time of light. Accordingly, this study revisited Rømer’s method as a student-led undergraduate investigation using modern ephemerides and the open-source planetarium software Stellarium.

In this case study, students simulated immersion and emersion timings for Io were recorded across two observing intervals in 2025–2026, selected so that Earth was alternately moving towards and away from Jupiter. Predicted eclipse times were compared with the simulated observations as the Earth–Jupiter distance changed by 1.929 au. Analysis of the cumulative timing delay yielded a speed of light of (2.996 ± 0.078) × 10⁸ m s⁻¹, in close agreement with the accepted modern value. As part of the inquiry-based design, the students were also required to establish and justify an appropriate sampling strategy, document a reproducible observational procedure, quantify uncertainty, and communicate the investigation in the form of a scientific manuscript.

Overall, combining Rømer’s original reasoning with contemporary simulation tools retains the experiment’s quantitative rigour while expanding its educational value. The activity integrates orbital motion, eclipse prediction, model–data comparison, uncertainty analysis, and scientific communication. In this way, a seventeenth-century astronomical discovery becomes an accessible yet rigorous framework for introducing undergraduates to the methods of contemporary planetary and space science research.

ABSTRACT. Maintaining accurate solar pointing is essential for obtaining high-quality observations from high-altitude balloon missions, where platform motion and environmental disturbances can rapidly degrade image quality. This work presents the development of an autonomous software-based solar tracking system for the Monash High Altitude Balloon (MHAB) scientific payload. Using a dedicated tracking camera mounted beneath the scientific camera, the system continuously locates the Sun and provides closed-loop control of the telescope, enabling stable and reliable pointing throughout the mission.

The tracking algorithm processes frames from a live video stream to determine the solar centroid using a robust computer vision pipeline. The solar disk is identified through contour analysis and geometric validation, allowing unreliable detections caused by partial occlusions or image artefacts to be rejected before any telescope movement is initiated. A two-stage circle-fitting approach combines rapid algebraic estimation with geometric refinement, providing accurate and reliable solar centre determination under a wide range of observing conditions.

Once the solar centroid has been identified, the pointing error is used to iteratively control the stepper motor until the Sun is centred within the field of view. The algorithm then transitions to fine tracking using a reduced region of interest, increasing tracking speed while reducing computational requirements. This hierarchical approach provides both rapid acquisition and high-precision tracking during flight.

The system has been evaluated using real and simulated solar images representing a range of viewing conditions and partial occlusions. The results demonstrate reliable autonomous solar tracking and stable telescope pointing suitable for near-space scientific missions. All tracking data, including centroid estimates, pointing corrections, confidence metrics and system telemetry, are archived during flight, providing valuable datasets for performance evaluation and future software development. Designed with a modular architecture, the tracking software can be readily adapted to other scientific payloads requiring autonomous target acquisition and precision pointing, extending its application beyond solar observations to future high-altitude balloon and small-space missions.

ABSTRACT. For satellite communications, the most commonly used band is the UHF around 437Mhz, which makes it very susceptible to the intentional radio frequency Jamming. This intentional interference, can severely affect the telemetry, commanding and data transmission during critical mission phases. As a project founded by SmartSat CRC at UNSW Canberra Space, this research developed and validated a practical, lightweight system for real-time jamming detection focused on small satellite platforms communications. The system implementation combines OpenLST radios with NVIDIA Jetson Nano modules and a USRP B210 device used as jammer in a fully controlled environment. Based on per-packet telemetry metrics such as RSSI, LQI, SNR, and noise floor, the system employs a CNN-LSTM hybrid model to differentiate between normal communications and jamming events. The testing has demonstrated exceptional performance, with 99.88% cross-validation accuracy and 99.97% test accuracy, alongside excellent precision and recall. The response detection latency consistently stayed under 200 ms, making this solution viable for onboard deployment and fast response. Key innovations of this work include enhanced OpenLST firmware that provides additional telemetry data alongside with the three-phase experimental workflow (baseline, jamming, and recovery) covering tone, barrage, and pulsed waveforms, plus a real-time inference pipeline, which collectively enable reliable detection under realistic conditions while operating with the limited resource constraints typical of space hardware. The resulting framework strengthens satellite link resilience and contributes to broader efforts in space domain awareness. It also sets the stage for future extensions, such as identifying different types of jamming and eventual testing in orbit. Overall, the work highlights the increasing use of edge-based AI techniques for more reliable space operations.

ABSTRACT. As Earth-observation constellations grow from technology demonstrators into fleets of tens to hundreds of spacecraft, a question of constellation design emerges: can the fleet improve its on-board machine-learning models collaboratively, in orbit — and does that capability survive growth, when every inter-satellite exchange must traverse scheduled optical links and the hop count between the farthest spacecraft rises with fleet size?

This study answers that question empirically for a fully satellite-autonomous architecture. Each spacecraft trains on its own locally collected, regionally biased data and exchanges model updates with in-view neighbours as Bundle Protocol v7 bundles over a store-carry-forward DTN — the link discipline standardized for deep-space communication — with no ground aggregation of any kind. Our interest here is neither the learning algorithm nor the transport, both held fixed, but the scaling behaviour of the whole.

Walker constellations of 12, 24, 48 and 96 satellites are evaluated against a fixed six-region learning task, constructed so the centralized upper bound and isolated lower bound are invariant while fleet size and network diameter alone grow. Collaborative training recovers the full isolated-to-centralized performance gap up to 48 satellites, and 88% ± 14% of it at 96 (six seeds, 100% bundle delivery throughout). The 96-satellite softening is a mixing-time effect of network diameter, not a hard ceiling: doubling the per-satellite exchange budget lifts the slowest runs and halves the spread, with a residual gap remaining. We further examine plane-level gossip topologies as a bandwidth lever: routing cross-plane traffic through a single fixed per-plane representative collapses fleet consensus, while rotating the representative role restores it at a 4× reduction in cross-plane link contention — the scheduling of the role, not the hierarchy, is what decides. Together these results give constellation designers a first empirical sizing rule: exchange budget must grow with network diameter, and representative rotation buys bandwidth without consensus loss.

ABSTRACT. Knowledge of spacecraft attitude is essential to meet strict pointing requirements for the next generation of small satellite missions such as ultra-high resolution Earth observation, secure laser communications, space-based interet-of-things (IoT), and space situational awareness. Spacecraft attitude refers to the spacecraft's position and orientation relative to a reference frame such as the Earth, or the Sun. Small degradations in sensing performance can significantly reduce pointing performance and mission capability. Small optics with limited light gathering capabilities, lower moments of inertia, limited onboard resources, such as size, weight, power, cost (SWaP-C), momentum storage, and propulsion capability, reduce the ability of smaller satellites to reject or compensate for environmental disturbances and maintain precise pointing over extended periods.

One of the major contributors to this degradation is high frequency, low-amplitude, 3D vibrations induced by internal actuators and external perturbations. Through the use event-based cameras (EBCs), inspired by neuromorphic vision, and novel algorithms we determine high frequency (>10 Hz) 3D spacecraft angular motion for resource-constrained small satellites. This high frequency estimation lays the groundwork for a dual-stage fine pointing system using EBCs in the order arcseconds (one arcsecond is 1/3600 of a degree) through combining with a low frequency (<10 Hz) attitude determination and control system (ADCS) using star trackers or other high and coarse precision sensors.

Unlike a regular active pixel sensor (APS), in an event-based sensor each pixel works asynchronously to record changes in light intensity. This allows an EBC to have microsecond-level temporal resolution, high dynamic range and operate at a fraction of power requirements of a space-rated active pixel sensor with similar resolution. These characteristics make EBCs well suited for low latency space applications.

The high frequency relative attitude estimation algorithms have been developed and first tested on a custom-built 3D simulation environment consisting of star field datasets using Tycho-2 star catalogue, sensor and camera parameters (size, resolution, field of view, noise), coordinate frame transformations based on pointing target, slew and perturbations, and a pin-hole camera model. Initial results demonstrate their effectiveness in high frequency spacecraft angular velocity and attitude estimation demonstrated by performance on pointing error indices and estimation time. The next steps involve testing the algorithms on real-time EBC datasets of star fields to close the sim-to-real gap and hardware-in-the-loop testing with controllers and fine pointing actuators for the dual-stage fine pointing system.

ABSTRACT. Ionising space radiation found in Low Earth Orbit (LEO) contributes to degradation and potential failure of electrical components within orbiting satellites. Experimental space radiation testing is vital for assessing unqualified components. This typically involves exposing susceptible components to multiple monoenergetic beams of protons and electrons at several pre-determined energies. However, such experimental testing, particularly for low-budget CubeSat and SmallSat missions, is often disregarded due to limited access to testing facilities and restricted funding. Omitting crucial radiation testing from the design process can lead to unplanned spacecraft failure, resulting in these missions contributing to space junk and pollution in LEO.

This work presents a practical and reproducible method of emulating the trapped proton spectrum in LEO through design of proton beam degraders, comparable to degraders utilised for radiotherapy purposes. These degraders would allow for space qualification testing from a single beam exposure rather than multiple exposures at single energies, reducing the required beamtime and hence the associated testing costs. Additionally, this method demonstrates the potential for adaptation of existing medical based proton facilities for space radiation testing, enabling easier access to space radiation testing. Degraders were designed and validated using a simulated model of the Holland Proton Therapy Centre Research and Development (HPTCR&D) beamline using OpenGATE10. Using the HPTCR&D OpenGATE10 beamline model, a database of proton kinetic energy flux spectra scored from multiple thicknesses of PMMA was constructed. Reference trapped proton energy spectra were obtained from the European Space Agency’s (ESA) Space Environment Information System (SPENVIS). To validate degrader performance, proton kinetic energy spectra, dose uniformity, and Linear Energy Transfer were explored. For experimental validation, the optimised proton beam degraders will be 3D-printed and deployed at the HPTCR&D beamline.

ABSTRACT. Physical laws allowing the production of propulsive energy from the liberation of accreted mass are explained through a force reaction that produces a pair of equal and opposite orbital trajectories that both ascend. The Cosmic Yoyo Anti-Gravity Drive variant is a design for a vehicle that is capable of efficiently producing propulsive energy by reversing the accretive process that produced the prime gravitational field. As the initial orbits are by definition representative of a certain limit of the gravitational potential, any orbital energy applied positively will alter the orbit in a manner opposed to the accretive process. The Cosmic Yoyo is bound by the internal force it can produce, the separation distance and its own inertia. Optimal deployment of this new technology therefore requires analysis of the various capacities that can be provided to the functional elements, thereby providing a realistic estimation of the utility of this invention. The internal propulsion is generated by two opposing canons that fire projectiles which are designed to bounce off each other as they are fired simultaneously towards each other. The size of the canon is esti- mated to be safe, useful and of a scale compatible with modern launch systems. The canons are to be coupled by cables housed within reels, which are mounted to span two opposing assemblies that clasp the respective canons. The cable length is a crucial dimension that determines the maximum separation distance. These cables are not required to bear significant loads, so they are optimised for length. A Payload Reel Assembly is located midway between the two “Yos”. The Payload Reel is intended to launch and receive payloads using an electrodynamic tether that is rotated on the main orbital plane using torque generated by the Yos. When the payload cable reaches a required rotational velocity, it is extended towards its limit. This action is the main mode and accelerates the payload cable (and any suitable payload) and decelerates the Payload Reel and the Yos. The moment the Payload Cable is launched, the Yos are launched with sufficient velocity as to provide enough orbital energy to propel the Yos and the Payload Reel Assembly to converge along the original orbit. Some initial propulsive energy may be withdrawn via a reciprocating yoyo action, with losses only due to friction and radiative losses as the launch momentum is reabsorbed. Propulsive force applied to the Payload Cable produces orbital energy that remains and can be reversed by mirroring the initial motions. This reversal provides the productive capacity of the vehicle. The reversal can be a launch or collection of a payload, or it can be an energetic interaction, such as a bounce. Operation of the Cosmic Yoyo requires rotational motion that is residual within the vehicle. Gyroscopic effects are intrinsic, however, there are approaches that can help avoid material failure or complications and thereby address foreseeable hindrances. Comprising structures are required to manage the impulse of the large forces that are to be applied and transferred to more sensitive componentry. The vehicle is also required to produce oxyhydrogen from generated water to enable its continuous use.