CPS Session at the IAU General Assembly 2024

Time

Speaker

Title

10:00

CPS-1 poster session

Ana Cecília Soja

Simulating the impact of satellites on astronomical observations

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A new era begins in astronomy, with the launch in the coming years of several terrestrial and space telescopes that will increase by thousands of times the amount of data we have available to understand the sky. Along with the challenge of analysing this unprecedented volume of information, there is a difficulty that is not well understood to date: the negative impact that satellite luminosity can have on observations. It is estimated that a project like Vera C. Rubin Observatory, for example, will have 30 to 40% of its images compromised. From a political point of view, we know limiting these launches is infeasible. For this reason, the alternative for observational astronomy is to develop new strategies to deal with the satellite luminosity contamination. One of them is building image processing pipelines that allow terrestrial observations to continue. Many working groups have already developed mitigation strategies and carried out tests of their efficiency on real images. In our research, we investigated the models used to date and their efficiency. It became clear that the simplest alternative, the single mask, is not efficient enough to make the images scientifically suitable. Therefore, it is necessary that more complex models, for example, that adapt the variation in luminosity to the trail, are developed.

Emma Louden

SIRI: A Risk Assessment Tool for Satellite Interference on Ground-Based Astronomy

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Ground-based telescopes have long been pivotal, generating the majority of astronomical data by volume and coverage. However, the influx of satellites is reshaping ground-based astronomy. Satellites now streak across once-clear fields of view, disrupting radio signals. In 2010, there were fewer than 1000 satellites; by September 2023, there were over 9000. This rise concerns astronomers, particularly with the impending launch of around 500,000 more satellites alongside the development of 30-metre, billion-dollar telescopes. The increasing saturation of our skies with artificial satellites threatens the functionality of ground-based observatories. To address this, we propose a proactive measure: identifying the most vulnerable ground-based astronomy cases and developing a ranking system to prioritise resource allocation. By determining which scientific investigations are most at risk from planned satellite constellations, we can prioritise the development of solutions, such as new space-based telescopes or advanced mitigation strategies. Our risk matrix, the Satellite Interference Risk Index (SIRI), categorises ground-based astronomical cases based on threat level, mitigation abilities, and importance to the scientific community. This ranking system will inform policy decisions, helping space agencies and funding bodies decide which ground-based projects to continue funding, which projects will require space-based alternatives, and which ground-based instruments and observatories most need mitigation techniques.

Maria Isabel Romero Colmenares

Determining the efficiency, accuracy, and precision between supervised and unsupervised machine learning algorithms in hunting for satellite streaks in astronomical survey images

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The increasing presence of LEO satellite constellations like Starlink raises concerns for astronomical observations. These satellites leave faint trails, impacting data quality across various disciplines, including space telescopes. Machine learning offers a promising avenue for addressing this challenge through anomaly detection techniques.

Both supervised and unsupervised methods can be utilised. Supervised learning requires pre-labeled data, while unsupervised methods identify deviations from "normal" astronomical images. Ground-based observations from diverse locations provide valuable data for training and validating these models, ultimately enabling the identification and mitigation of satellite constellation trails.

Research groups like CLEOsat and the IAU's CPS have studied the impact of LEO satellites, relying on observations from various observatories at the expense of dedicated science time. ML offers a solution by automatically identifying satellite trails in existing data, such as long-term astronomical surveys. Unsupervised methods have proven successful in other astronomical applications, prompting its exploration for satellite trail detection.

This work presents the development and accuracy of an unsupervised ML method for classifying images with and without satellite trails. While both supervised and unsupervised methods could potentially identify contaminated images, their comparative performance remains unaddressed. This research aims to compare their effectiveness in detecting satellite trails in publicly available surveys, ultimately providing a valuable tool for astronomers and satellite operators to study and mitigate these potential impacts.

Jeremy Tregloan-Reed

CLEOsat: Combating Satellite Constellation Impacts on Astronomy through Research, Policy, and Collaboration

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The Chilean Low Earth Orbit Satellite (CLEOsat) group actively researches the impact of satellite constellations on astronomy through collaborative observational campaigns with the IAU Centre for the Protection of the Dark and Quiet Sky from Satellite Constellation Interference (CPS), currently focusing on AST SpaceMobile's Bluewalker 3 and Starlink V2 mini-satellites.

Additionally, CLEOsat conducts independent campaigns utilising its network of telescopes across Chile, Spain, Mexico, Vietnam, and South Korea, aiming to characterise the multi-wavelength reflective brightness of OneWeb and Starlink satellites and assess the accuracy of supplemental Two Line Elements (TLEs) for orbit determination.

Beyond research, CLEOsat actively contributes to national and international policy and regulations. Members participate in developing regulations to minimise ground-based light pollution and protect observatories in Chile. Notably, they provide expertise and advice to the Chilean Ministry of Transport and Telecommunications regarding the licensing of ground stations used by satellite operators. Furthermore, CLEOsat members represent Chile within the IAU CPS policy hub group of friends, contributing to international dialogue and policy formation.

This multifaceted approach empowers CLEOsat to effectively address the challenges posed by satellite constellations, ensuring the continued viability of astronomical research and the protection of the night sky.

Stanislav Karpikov

Toward an Enhanced Civil Space Situational Awareness System Based on Compact Semi-Professional Tools for Satellite Observation and Monitoring

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The increasing number of satellites in low Earth orbit has revealed the limitations of current Space Situational Awareness (SSA) services and tools in accurately predicting the trajectories of satellites and space debris within images. Previous reports have highlighted errors in time and position calculations based on available data (NORAD, for example). There remains a shortage of public services for predicting trajectories and coordinating observations. This process involves estimating probabilities, variations in traffic density by season and location, and classifying brightness and iridescence, among other factors. A service implementing a big data approach would be suitable for all kinds of tools, including post-processing techniques, trail avoidance strategies, observation scheduling, or employing mid-exposure shuttering (following the approach proposed by StealthTransit).

The task of gathering information on hundreds of thousands objects can be done through a distributed system– data grid (Space Surveillance Grid) engaging both professional and amateur astronomers. This study analyses the requirements for such a system and discusses an approach that integrates relatively inexpensive (and thus accessible for widespread use) yet self-contained tools based on individual telescopes and cameras, joined into a global data collection network.

The potential scale and parameters of such a system are examined. For instance, it could enable the creation of a real-time 2D map of the sky featuring tracked objects, with some level of estimation for the third coordinate, with the error depending on the number of devices in a given area.

10:30

CPS-1: Introduction; SatHub, Updates on observations and software

10:30

Connie Walker

Welcome, Introductions, Housekeeping

10:35

Richard Green

Status of the "field": present challenges & mitigation solutions

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As astronomers are acutely aware, satellite constellations in low Earth orbit create sunlight streaks impacting optical/infrared observations and produce radio emissions affecting radio observations. While technology advancement pushes for more and larger satellites, measurements also show effective approaches to reducing effects on optical/IR and radio observations. In addition to radio communication signals, electronics in satellites create unintended low-frequency emissions that are detectable from the ground.

The IAU’s Centre for the Protection of the Dark & Quiet Sky from Satellite Constellation Interference (IAU CPS) is taking multiple approaches to mitigate negative impacts. At least 14 operators meet under their auspices to share best practices and understand astronomical concerns. Observing campaigns are organised, and predictive software for position and brightness of satellites impacting planned observations is well into development. Educational videos about satellite constellations are available, and ongoing efforts are underway to engage with broader interested groups. CPS-affiliated policy and space law experts have developed and are refining recommendations for ultimately turning best practices into a model regulatory framework. Through the efforts of the IAU and other astronomy organisations, UN COPUOS is now adopting a five-year agenda item to consider astronomy and satellite constellations and the ITU-R is discussing protections for radio-quiet zones and radio astronomy bands from satellites. The IAU is leveraging its international constituency to address this urgent global issue.

10:45

Siegfried Eggl

SatHub Lightning Talk Kickoff

10:46

Priya Shah

An update on the satellite interference to dark skies

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This talk will focus on the satellite threat to observational astronomy. As a member of the Satellite Constellation Working Group: Observatories sub group a recommendation was drafted for the Dark and Quiet Skies 2 Report, which shall be discussed. I shall also discuss the SatHub and the education of observers about satellite constellations for regular citizens, amateur astronomers and professional astronomers and the outreach activities planned. A recent update on the present status will be presented.

10:48

Constance Walker

The Impact of Large Satellite Constellations on Optical Astronomy

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The deployment of communication satellite constellations in low Earth orbit (LEO) may represent a valuable step forward in improving world connectivity. However, the sun-reflected luminosity and radio-frequency emissions from a large number of satellites can have a serious impact on astronomical observations, as well as on the pristine appearance of the night sky. In recent years, various strategies for co-existence in terms of optical astronomy have been developed. There are now better models and data for satellite brightness, which are key to enabling mitigation, active avoidance, or use in compliance checks. Future observations of commercial LEO satellites will determine, for instance, whether some coatings and Bragg mirrors on reflective surfaces of Starlink satellites will help and how well. For spectroscopy, better modelling and understanding of satellite spectra will enable the emission from satellites to be calibrated out of astronomical data. Autonomous imagers on large spectroscopic facilities can help identify when an exposure was contaminated. For observatories, there are software solutions for streak detection and elimination that may help. During the presentation, we will discuss mitigation strategies through software and observation and provide updates in the areas of policy, industry and community engagement, some of which is being led by the IAU Centre for the Protection of the Dark and Quiet Sky from Satellite Constellation Interference.

10:50

Abdelkarim Boskri

Enhancing Satellite Observation Capabilities: The Role of Oukaimeden Observatory

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The Oukaimeden Observatory, as a proud partner of the IAU-CPS centre, plays a crucial role in satellite observation initiatives. Equipped with a diverse array of professional and amateur telescopes, the observatory offers comprehensive satellite observation services and actively engages in daily monitoring activities. Moreover, it serves as a hub for collaboration with other observation programmes, providing both facilities and training opportunities for academic and professional development in observational techniques. Leveraging advanced orbital data processing techniques, the observatory has developed innovative platforms to streamline observation planning, thereby maximising its contributions to the scientific objectives outlined by the IAU CPS Centre. In this contribution, we highlight the progress made by the Observatory team and the facilities available to observatories worldwide, fostering a collaborative environment for advancing satellite observation and data analysis programmes.

10:52

Zeljko Ivezić

The Impact of Satellite Constellations on the Vera C. Rubin Observatory Legacy Survey of Space and Time

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Beginning in 2025, the Rubin Observatory Legacy Survey of Space and Time (LSST) will survey the southern sky with unprecedented cadence and depth and open new windows to discovery in all areas of astrophysics. At the same time, satellite companies are launching new hardware into low Earth orbit (LEO) at a rapid pace, and estimates predict about 50,000-100,000 active LEO satellites during the decade of LSST Operations. This presentation will begin with an overview of how streaks from LEO satellites due to reflected sunlight can affect LSST data products and science goals. It will then discuss work underway to quantify and mitigate the science impacts, such as modifying the observing strategy to avoid some satellites, identifying glints and flares, and detecting streaks so the LSST alert stream does not include them.

10:54

Jeremy Tregloan-Reed

Hunting for satellite trails in astronomical images with machine learning

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The proliferation of low Earth orbit (LEO) satellite constellations raises concerns for ground-based and space-based astronomy due to their impact on the night sky. Research groups like CLEOsat and the IAU's CPS are working to quantify this impact, but doing so requires dedicated observing time, diverting resources from scientific astronomy.

This work proposes a solution using pre-existing data from wide-field surveys, which inevitably capture satellite trails. However, analysing terabytes of data containing a mix of clear and contaminated images is computationally expensive.

We address this challenge by developing a supervised machine learning algorithm trained on datasets with equal numbers of clear and satellite trail-contaminated images. This approach leverages existing "wait and catch" observations from the CLEOsat network, ensuring balanced training sets and mitigating potential bias.

Our algorithm is currently undergoing validation on public data from WASP and HATNet, with initial results showing promising accuracy (96%). This work paves the way for utilising machine learning to efficiently analyse existing astronomical data and alleviate the burden on dedicated observing time, ultimately aiding astronomers in understanding and mitigating the impact of LEO constellations on the night sky.

10:56

Maria Isabel Romero Colmenares

OneWeb Satellites Photometric Modelling: Specular and Diffuse Components

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The proliferation of low Earth orbit (LEO) satellite constellations, with tens of thousands planned from companies like OneWeb and Starlink, raises concerns for ground-based astronomy. These satellites leave trails in astronomical images, impacting research across various disciplines. Studies have measured the reflective brightness of Starlink satellites (Boley et al. 2022; Tregloan-Reed et al. 2020, 2021; Tyson et al. 2020) to quantify these risks.

This study investigates the impact of the OneWeb constellation and its reflective brightness, whilst considering satellite design, solar phase angle, range, effective albedo, and effective cross-section. Observations of over 300 OneWeb satellites from the 0.6m telescope at the Chungbuk National University Observatory (CbNUO), combined with diffuse sphere models (e.g. Boley et al. 2022; Pradhan et al. 2019), demonstrate the feasibility of identifying operational ("On-station") and non-operational ("Off-station") satellites based on their brightness. Additionally, the phase angle can be used to provide an estimate of the observation direction. This research provides valuable insights into the impact of OneWeb constellations on astronomical observations and lays the groundwork for further mitigation strategies.

10:58

Warren Skidmore

The scientific importance of Laser Guide Star AO Systems and impacts arising from the protection of LEO satellites.

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The scientific output of ground-based observatories is becoming increasingly dependent on the use of laser support adaptive optics systems. I will show that as we move toward the era of the ELTs, the majority of the envisioned science will depend on laser guide star supported AO. Presently, any ground based observatory related to the United States is required to adhere to the US Laser Deconfliction Policy, which means that laser propagation from the ground has to stop as and when set by the Laser Clearinghouse. With the continuing rise in the number of LEO satellites, a situation will arise where laser supported adaptive optics operations will become essentially impossible. I report on efforts to evaluate the risk to space assets from astronomical lasers and moves to adapt the policies to enable laser guide star supported science by US facilities.

11:00

Siegfried Eggl

The IAU CPS SatHub: Updates on observation campaigns, services and software to mitigate satellite constellation interference

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SatHub is one of the four hubs of the IAU Centre for the protection of the Dark and Quiet Sky from Satellite Constellation Interference (IAU CPS). SatHub focuses on observation campaigns, brightness data analysis and software curation to improve our understanding of the impact of satellite constellations on astronomy and observers worldwide. That includes online services hosted in concert with our contributing members that simplify satellite constellation mitigation in astronomical observation planning. In this contribution we will give a summary of services offered by SatHub and its members and discuss the current status of satellite constellation observation campaigns for several operators and across the electromagnetic spectrum. Online services such as SatChecker and the Satellite Constellation Observation REpository (SCORE) will be presented.

11:02

Nadeem Oozeer

Satellites' Radio Frequency Interference: its impact on radio astronomy.

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Radio frequency Interference (RFI) is any unwanted radio signal that affects/impacts astronomical data. RFI comes from different sources, both artificial and natural. By analysing radio data from the MeerKAT, I will present the various sources of RFI around the future Square Kilometre Array (SKA) mid-site, and how it impacts radio astronomy.

11:04

Federico Di Vruno

The impact of large satellite constellations on radio astronomy

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This talk will give a broad overview of the different effects that large satellite constellations (existing and planned) can have on radio astronomy receivers and science.

11:06

Harry Qiu

SCEPTER: Simulation of Active Constellation Emissions for Radio Telescopes

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With the recent rapid development of satellite constellations, we face an increasingly challenging radio spectrum environment for observations. As large satellite constellations continue to expand in the near future, both protection and mitigation work for radio astronomy will require a detailed understanding of the potential impact during observing. While studies of constellations can be conducted, there is a need to model and predict the impact of operating satellites for telescope operations and generalised impact studies. SCEPTER is a simulation tool designed by the SKAO to model satellite power flux densities across the whole sky. This will allow the SKAO and other radio telescopes to identify avoidance zones for observation planning and radio dynamic zones.

11:08

Matthias Schartner

Active spaceborne RFI mitigation strategy for VLBI

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The increase in radio frequency interference (RFI) from satellites in space is causing issues for Very Long Baseline Interferometry (VLBI) observations. In particular, satellite mega-constellations such as Starlink pose a significant threat since these satellites will emit signals in the upper-frequency range of the VLBI Global Observing System (VGOS). The power of these signals may saturate the amplifiers of VGOS antennas, causing nonlinearities within the observations.

As an active mitigation strategy, we have extended the VLBI scheduling software VieSched++ to account for satellite orbit information in the form of two-line-element (TLE) files. Based on this information, observations in the direction of potentially harmful satellites can be avoided to reduce the impact of spaceborne RFI. However, this strategy adds additional constraints to the scheduling algorithm, affecting the efficiency of VLBI observations. We will share simulation results comparing the impact of these constraints on parameter precision with and without our active avoidance approach. While our active mitigation approach helps, we will also discuss its limitations and future development steps.

Additionally, we will highlight the deployment of a user-friendly database (https://satdb.ethz.ch/ [https://satdb.ethz.ch/]) to simplify access to satellite TLE information within a specific time span and based on an observed frequency sequence. The database is publicly accessible via a web interface and an application programming interface (API).

11:10

Boris Sorokin

List of radio astronomy stations as a database for sharing and compatibility studies

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In the evolving landscape of spectrum sharing between radio astronomy observatories and satellite operators, the interplay between them becomes more and more important. Historically it was up to national administrations to support data exchange between different radio spectrum users. However, with rapid satellite development a need for a more global approach arises.

Our discussion extends to the development and utilisation of a CPS-based database, incorporating data from a snapshot of the Master International Frequency Register (MIFR) to house radio astronomy observatories’ characteristics. This database not only serves as a vital resource for sharing and compatibility studies within the IAU CPS framework but also addresses gaps in existing registries by including data from unfiled observatories, like the South Pole Telescope.

Furthermore, we introduce a novel tool designed to help those with access to the ITU database, allowing for efficient retrieval of radio astronomy station data. This tool, aimed at both the radio astronomy and satellite communities, promises to streamline the process of conducting sharing and compatibility studies by providing comprehensive access to essential parameters, including station and antenna specifics, frequency bands, and operational details. This initiative represents a significant step forward in ensuring the harmonious coexistence of satellite and radio astronomy operations, bolstering the efficacy of global regulatory frameworks.

11:12

Liroy Lourenco

Viability of spatial nulling using ASKAP PAFs to mitigate satellite interference.

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ASKAP currently discards data in the band from 1150–1300 MHz and 1500-1620 MHz due to satellite interference (Hotan et al. 2021, Lourenço et al. 2024). The proliferation of LEO satellite constellations, particularly direct-to-cell, could mean discarding more data. ASKAP, therefore, requires additional (active) RFI mitigation techniques. Specifically oblique projection (Hellbourg et al., 2012) — places nulls in the beampattern in the direction of the satellite without degrading the gain of the main lobe — is possible using ASKAP’s phased array feeds (PAFs) and involves updating beam-weights throughout an observation. We have validated this using SEFD and holography measurements on astronomical sources while mitigating a self-generated interferer.

The effectiveness of oblique projection depends on identifying satellite RFI-affected channels and estimating their subspace (direction[s]). The impact of oblique projection on beam shape and sensitivity depends on the orthogonality of the eigenvectors defining the RFI subspace and the subspace of the astronomical signal defined by the beam-weights. Hellbourg and Bannister (2017) have already shown mitigation of satellite interference using six ASKAP antennas. We present forward predictions of spatial nulling on candidate satellite interferers identified as suitable for mitigation without using reference antennas or caching ACMs to determine the RFI subspace. We show that (pending further work to estimate the RFI subspace in real-time continuously) suppression of the RFI with a 1% increase in system noise temperature should be possible and would enable high dynamic range imaging in ASKAP's 1 MHz continuum mode in bands where ASKAP currently discards data due to satellite interference.

11:14

Mike Peel

The potential impact of satellite constellations on Cosmic Microwave Background experiments

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Cosmic microwave background experiments observe large angular scale emission at extremely high sensitivity at 10-1000GHz. At these frequencies, satellites both actively transmit (currently around 10GHz, extending up to ~200GHz in the future), and will be thermal black bodies/reflectors of thermal emission. While small numbers of satellites can be ignored as glitches, the dramatic increase in satellite numbers over recent years means this component has to be taken into account with future ground-based CMB experiments. This presentation will describe work so far to understand the effect of satellites on CMB experiments, using observations of individual satellites by the Atacama Cosmology Telescope (ACT), the South Pole Telescope (SPT), and the SCUBA-2 instrument on the James Clerk Maxwell Telescope (JCMT). The presentation will also cover the extrapolation of these observations to make predictions of the overall impact on observations by entire satellite constellations.

11:16

Hamid Idelbacha

Enhancing Satellite Trajectory Monitoring: A Machine Learning Approach for Anomaly Detection and Classification

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Given the continual increase in the number of satellites in orbit, there is an escalating need to enhance trajectory models and operational risk management to gain a deeper understanding of orbital anomalies, such as unexpected changes in a satellite’s orbit, which can have a significant impact on satellite operations and threaten human and financial resources. This study aims to employ machine learning techniques to identify abnormal or divergent changes in satellite trajectories, from datasets containing multiple sets of Two-Line Elements (TLEs). The automatic detection of these behaviours has the advantage of avoiding the computation of satellite position and velocity. In this case, which is an unsupervised framework, we have selected the LOOP (Local Outlier Probability), One-Class SVM (Support Vector Machine), and Isolation Forest methods. We choose these methods for their different perspectives on density and distance. Once anomalies are detected, it is interesting to categorise them based on their causes using supervised machine learning methods, namely Random Forest, SVM, and artificial neural networks. The quality of classification is evaluated using standard metrics such as the confusion matrix, precision, recall, and F1 score, with achieved results of an average precision of 89%, a recall of 90%, and an F1 score of 88% for four anomalies classes: Propulsion, Deliberate, Battery, and Accidental Collision.

11:18

Ayoub Abdou

Development of a Python script for calculating orbital parameters and satellite magnitude: Validation through observational data from BlueWalker 3

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In this abstract, we present our developed Python script for processing images of artificial satellites and space debris observed through telescopes at the Oukaimeden Observatory. The script calculates the orbital parameters and apparent magnitudes of observed objects, allowing for calibration of their luminosity to standard parameters such as distance and phase angle. to allow a direct comparison of their reflective brightness in different observations. Validation results will be present from observational data of the bright constellation BlueWalker 3, confirming the reliability and accuracy of the script.

11:20

Olivier Beltramo-Martin

SpaceAble and the Dark Sky: Sky observation by and for citizen astronomers

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The proliferation of satellite constellations in orbit poses significant challenges to ground-based astronomical observations and space sustainability. Collaboration between institutional and private entities is essential to address the light pollution generated by these satellites, spanning from optical to radio frequencies, and mitigate debris impact on space operations.

To mitigate this pollution, accurate tracking of orbiting objects is crucial. SpaceAble, a French startup specialising in Space Situational Awareness (SSA), is developing a scalable optical sensor network to improve the accuracy of orbit predictions. Partnering with organisations like the IAU-CPS since 2022 and collaborating with citizen astronomers, SpaceAble aims to establish a global community dedicated to safeguarding space observation.

SpaceAble's initiatives include joining the France 2030 funding programme with the DOSSA project - Decentralization of Space Situational Awareness, in partnership with Unistellar, to develop remote telescope control and image processing capabilities. DOSSA is also a collaboration with academic institutions like the Laboratoire d’Astrophysique de Marseille and Cadi Ayyad University, to enhance detection algorithms to improve sensitivity to smaller objects with deep-learning techniques. Furthermore, SpaceAble is working on commercialising standardised data for space traffic management and space weather, catering to both institutional and private sector needs.

This session provides an opportunity to showcase the progress and commitments of this international collaboration, inviting additional observatories to join efforts under the IAU-CPS to address orbiting object pollution for ground-based observations.

11:22

ALL

SatHub Open Discussion and Q&A

12:00

LUNCH

13:30

CPS-2a: Policy Recommendations, Requirements, Norms, Frameworks and Guidelines

13:30

Andy Williams

Policy Overview: The Development of Dark and Quiet Skies Standards in Government and Industry

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The astronomical community has made significant strides in highlighting the ramifications of satellite constellations within political and industrial spheres. Despite this success, the absence of specific government regulations safeguarding optical reflections remains a concern. Current measures, albeit limited, are in place under the auspices of the International Telecommunication Union (ITU). This presentation focuses on the initiatives undertaken by the European Space Agency — the development of the Space Debris Mitigation Standard, and also the European Union Space Sustainability Labels. Remarkably, these standards may represent a crucial milestone as the first mandatory directives addressing the preservation of dark and quiet skies. In the absence of comprehensive regulatory frameworks and their protracted timescale for development, the establishment of voluntary standards and guidelines becomes imperative.

This talk reviews the progress of these mandatory and voluntary standards, reviewing their efficacy and potential for future development. By examining the evolving landscape of dark and quiet skies standards, we provide insights into the ongoing efforts, challenges, and prospects within the astronomy community.

13:38

Yana Yakushina

Protection of Dark and Quiet Skies at the National Level: Conclusions and Recommendations

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The protection of dark and quiet skies (D&QS) has garnered heightened attention across various regulatory levels. This surge in interest is attributed to the widespread proliferation of artificial light at night (ALAN), leading to terrestrial light pollution (LP), and separately, an escalating deployment of mega-constellation satellites in low Earth orbit (LEO), resulting in orbital light and radio spectrum pollution. Changes in nighttime brightness have resulted in complex concerns ranging from detrimental effects on astronomical observations to adverse impacts on the environment. These concerns have prompted some national states to take action to address challenges related to the disappearance of D&QS with a focus on the adoption of ground-based light and noise pollution prevention measures.

Following the preliminary work presented at the IAUS385, this presentation will introduce the final conclusions and recommendations of the research conducted by the IAU CPS Policy Hub, WP 2, National Analysis team. The team has investigated over 70 different jurisdictions worldwide to identify approaches towards protection D&QS. The presentation outlines the research methodology, delivers conclusions and recommendations, and provides illustrative examples from national regulatory frameworks. For a more comprehensive analysis, the research was focused on three primary dimensions: (1) protection of dark skies (addressing aspects of LP); (2) protection of quiet skies (addressing aspects of radio/noise pollution); and (3) satellite regulations (encompassing registration, authorization, and technological requirements). Overall, the work builds an understanding of national approaches aimed at D&QS protection and allows for the identification of potential regulatory improvements in this realm.

13:43

Marieta Valdivia Lefort

Protection of Dark and Quiet Skies: Recommendations for the decision-making process

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The protection of dark and quiet skies (D&QS) is starting to get more attention from governments and interest groups worldwide due to the work done by astronomical and environmental societies in this respect. This work has involved raising awareness on the proliferation of artificial light at night (ALAN) and the increased terrestrial light pollution (LP), and also the escalating deployment of mega-constellation satellites in low Earth orbit (LEO) affecting astronomical observations. Nevertheless, and despite these efforts, the process of achieving national policy and legislation on the protection of D&QS has not been straightforward or sufficiently effective in many cases.

Considering the above, this presentation gives some recommendations to be taken into account in the negotiation and decision-making process regarding the protection of D&QS at the legislative level. Thus, this presentation highlights both the strategies necessary to promote this issue and include it in the political agenda (advocacy, negotiating with interest groups, involving charities, etc.) and the elements of the decision-making process that could hinder the legislative process but that should indeed be considered (bureaucracy, legislative interest in the matter, etc.). Although with more emphasis on the British experience in this respect, the recommendations presented here can be extended to the rest of the countries.

13:48

Tamara Blagojevic

The effect of behavioural norms on developing Dark and Quiet Sky Protection frameworks in emerging spacefaring nations

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The preliminary results of the International and National Analysis teams of the IAU CPS Policy Hub showcased multiple benefits of implementing integrative, multidisciplinary and holistic research methods.

The International lens analysis revealed the necessity of due consideration of appropriate environmental principles and norms in dark and quiet skies protection, along with the Space Law framework. The benefits of an integrative approach were evidenced by the recent progressive shift in consciousness around space sustainability, which further influenced the emergence of various initiatives in the international and regional Space Law frameworks.

The examination of particular examples of the national Dark and Quiet Sky protection frameworks showcased that many emerging space faring nations carry out initiatives which can support the progressive development of the protection of dark and quiet skies and astronomical activities.

As a result of the overview through both international and national lenses, behavioural science mechanisms have been identified as a cohesive element that can enable a more integrative, inclusive and culture sensitive approach. Behavioural science incentives have been tested in the environmental sector and showcased positive results in influencing policy making globally. Moreover, since nonbinding legal instruments, known as soft law, can guide the development of binding, hard laws, human behaviour inspiring normative developments should be considered early on in the norm life cycle.

This presentation will examine the adequacy of the behavioural science mechanisms to contribute to the progressive development of the Dark and Quiet Skies protection framework, by analysing particular initiatives and incentives in exemplary national contexts.

13:53

Beatriz Jilete

Overview of ESA Space Debris Mitigation Requirements and compliance verification guidelines applied for dark and quiet skies

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The ESA Space Debris Mitigation Policy was updated in October 2023 accounting for the new ESA Zero Debris Approach. The new ESA Space Debris Mitigation standard (ESSB-ST-U-007, which exceeds the previous standard ECSS-U-AS-10C Rev.2) specifies design and operational measures that a mission needs to adopt through its lifetime to prevent space debris release and proliferation, control system break-up risk, control collision risk, control system failure risk, improve orbital clearance, assure safe re-entry and minimise impact on astronomy.

The requirements for the protection of dark and quiet skies encompass the limitation of optical and radio frequency interferences with ground and LEO astronomy, prediction and sharing of information on the brightness during the mission design, and promotion of mitigation actions. The paper will explain in detail the new dark and quiet skies requirements included in the standard.

In addition to the mitigation standard, ESA is preparing an update to the compliance verification handbook to be released before summer 2024. The handbook provides the guidelines on verification methods (e.g. prediction of brightness during mission design phase) and recommend mitigation measures in support to ESA missions to facilitate the compliance with the ESA Space Debris Mitigation requirements. The new version will be aligned with the current space debris mitigation standard. The paper will give an overview of the methods, guidelines and formulas that mission developers would be required to follow in order to be compliant with the new standard.

13:58

Carolyn Marie Crichton

EPFL Coordinates Research and Community Interests in Switzerland for the Protection of Dark and Quiet Skies

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EPFL is facilitating the Swiss conversation on Dark and Quiet Skies through multiple initiatives. To unite EPFL’s forces in the domain of sustainability in space, eSpace recently launched the Sustainable Space Hub (SSH). In order to coherently manage and foster the growth of these topics at EPFL, the hub connects the individual projects in a workflow that rests on three intertwined domains: measure, understand, and act. The presentation will focus on the activities within these domains related to the Dark and Quiet Skies initiative. The research initiatives that we will present are: (i) a project that evaluates the influence of space activities on astronomical observations using the methodology of the Space Sustainability Rating (SSR) with the goal of extending SSR by a new module such that it can account for that influence of future space missions, (ii) a research project to develop methods to detect satellites and space debris in large astronomical data archives that will help to better understand the growing influence of space objects on astronomical observations, (iii) tools that support engineers to incorporate space sustainability aspects already during mission design and (iv) community building activities to raise the voice of Swiss experts to for the Swiss delegation to the UNCOPUOS facilitated by the SKACH (Square Kilometre Array Switzerland). With this contribution we will help stimulate further activities aimed at bridging the gap between scientists, industry and policy makers in understanding and quantifying sustainability in space.

Policy Lightning Talk Session 

14:03

John Barentine

Project West Ford, the IAU’s response, and the framing of the Outer Space Treaty 1961–1967

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Since the dawn of the Space Age, astronomers have contended with uses of outer space that sometimes conflict with their research goals and priorities. Military users in particular created early friction with the astronomical community as exemplified by the U.S. military program known as ‘Project West Ford’ (PWF). Against the backdrop of the emergent Cold War, the U.S. tested an 'artificial ionosphere’ for radio propagation by placing thousands of copper dipoles into an orbiting belt. Despite the relative openness with which the U.S. conducted PWF, astronomers worried that the experiment would adversely impact ground-based (and future space-based) astronomy. The IAU expressed serious concerns about the planned PWF test at the XIth General Assembly, “warning of the grave moral and material consequences which could stem from a disregard of the future of astronomical progress”. While PWF ultimately did no harm to astronomy, the affair informed the framing of Article IX of the Outer Space Treaty, which requires launching states to exercise “due regard” in conducting activities that could yield “potentially harmful interference with … the peaceful exploration and use of outer space”. In this presentation I will review the history of PWF as it prompted astronomers of the era to react, providing important historical context for the ongoing issues involving astronomy and commercial space operators regarding large satellite constellations.

Lightning Talk Session 

14:05

Most. Farjana Sharmin

Increasing space actors and Mega-Constellation into LEO: Effect on Anthropocene, Analysing the role of global and regional space organisations and initiative to ensure sustainable use of space

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Space-based services have become tools of statecraft-to-civilian comfort. The commercial engagement and cost-effective space technologies revolutions make the domain accessible for multiple actors. Although many third world countries are still under non-space faring belt due to the lack of technological capacity and economic power. In the last few years the trend towards mega-constellations has been popular. Indeed, mega-constellations by state or private actors will bring benefits in many ways. However, the environmental aspect of outer space has been neglected by Anti-satellite Weapon testing. And the growing interest in mega-constellations in LEO has a large consequence in the Anthropocene. This study intends to analyse how the growing mega-constellations can be a threat to our environment and people, and what role could be played by the global and regional space organisations like the UN, ESA, APSCO, IAU and APRSAF to ensure the sustainable use of space. The study applies qualitative approaches and is followed by mixed methods.

14:07

Giorgio Siringo

Spectrum Management at ALMA

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We present here the work carried out by the Joint ALMA Observatory Spectrum Management Office (JSMO) and its commitment to RFI protection and prevention at the ALMA site. Coordination efforts between the Chilean national radio-communication authority SubTel and the ALMA European and North American representatives in Chile in 2023 made possible a 10-year renewal of the exempt resolutions that give ALMA radio protection in a 30 km radius and coordination in a 120 km radius on Chilean territory. Thanks to the efficient collaborative relationship with SubTel, we are evaluating the possibility of extending the two areas to the neighbouring territories of Argentina and Bolivia. Another topic of conversation with SubTel is to impose a minimum distance from ALMA to new satellite-constellation gateway stations installed on Chilean territory.

Our office is also involved at both national and international levels in developing synergies with groups active in the field of spectrum management, e.g. the radio committee of the SoChiAs, the multidisciplinary initiative CLEOSat, the CARF in Europe, the NRDZ in the USA. An aspect of particular importance for ALMA is the extension of the ITU Recommendations related to Radio Astronomy to cover frequencies from 275 GHz upwards, where more than 70% of ALMA's observation spectrum falls, and which is currently without any protections. We plan to maintain active participation in the preparatory work for the next WRC in 2027.

14:09

Pedro Sanhueza

An environmental approach to protect the dark and quiet skies for astronomy and society

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The impact on optical and radio astronomy of satellite constellations has been systematically studied in recent years. These adverse effects are highly relevant, posing a risk to the continuation of astronomical activities conducted from Earth. However, the proliferation of satellites in orbit and the re-entry of such satellites and space debris is currently affecting the natural darkness of the night sky and can also affect the stratospheric ozone layer and compromise the radiative balance of this layer. The metals produced by satellite particles burning up on re-entry into the atmosphere disperse throughout the stratosphere, potentially contributing to the destruction of portions of the ozone layer through chemical reactions. These environmental effects are currently unpredictable, though potentially very serious. It is urgent to study these effects and apply the preventive environmental principle to regulate the proliferation of satellite constellations based on current indications of possible damage, even though there is still no certainty about these environmental harms, which are already evident to astronomical science. This approach will safeguard the stratospheric ozone layer and protect astronomical science, providing a stable and predictable scenario for satellite operators to conduct their activities.

14:11

All

Policy Hub Open Discussion on Recommendations, Requirements, Norms, Frameworks and Guidelines

14:30

CPS-2b: Community Engagement

14:30

John Barentine

Engaging with diverse stakeholders about satellite constellations: foundations of the CPS Community Engagement Hub

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Large satellite constellations are rapidly remaking the continuum of environment from Earth to space in important ways, yet the input of many affected people and groups continues to be left out of decisions affecting the uses of outer space. The IAU Centre for the Protection of the Dark and Quiet Sky from Satellite Constellation Interference (CPS) aims to help bridge this gap where the effects of constellations on astronomy is concerned. The mission of the CPS Community Engagement (CE) Hub is to provide stakeholders outside of professional astronomy with a venue in which to be heard and to help clearly communicate their views and opinions to a wider audience. This presentation will focus on how CE Hub is engaging with stakeholders, raising awareness of the issue and providing important factual information and resources to inform ongoing discussions. We will review events, conferences, and actions of the astronomical community that led to the creation of the CE Hub and informed its foundations. We will then describe how the outcomes of those interactions have been incorporated into the CE Hub strategy and its initial plans and activities.

14:40

Jessica Heim

Creating educational resources to inform and engage diverse stakeholders on satellite constellation issues

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The IAU Centre for the Protection of the Dark and Quiet Sky from Satellite Constellation Interference (CPS) Community Engagement (CE) Hub was established to provide stakeholders outside of the professional astronomy community with a venue in which to be heard and to help clearly communicate their views and opinions about large satellite constellations to a wider audience. However, in its efforts to engage with various constituencies on the topic of satellite constellations, the CE Hub found that some stakeholders felt that they did not have enough information on the subject to form an opinion. While many were aware of the increasing numbers of satellites launched in recent years and that many of these were intended to provide broadband internet services, they were often not aware of more details related to these activities. Thus, the CE Hub decided to develop unbiased, fact-based educational materials to help fulfill the need for resources on this subject readily understandable by the public. In this presentation, we will give a brief summary of the CE Hub’s experience with this initiative to date; present some of our educational materials and resources; and discuss current and anticipated challenges in our efforts to aid in increased awareness of and interest in satellite constellation issues.

14:50

Samantha Lawler

Satellite education: "No, it’s not a UFO, it’s Starlink"

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Satellites are already changing the night sky worldwide, and many other companies are lined up to follow the same operational model. Despite efforts to reduce their brightness, Starlink satellites are easy to observe in the night sky, especially shortly after launch when they form "trains" and very low orbital altitudes while they gradually raise to their operating orbits. These have been seen all over the world by users of the night sky, whether or not they have the funds or government approval to use Starlink internet. Thus far, satellite operators' messaging to the public has been primarily focused on the services they aim to provide, but they do not appear to have put much emphasis to date on educating the general public about these highly visible satellites, or about the increasing number of satellites and rocket body re-entries that can be seen around the world. The lack of public education about these easily visible phenomena means that local astronomy departments in universities and amateur astronomy clubs have received a large burden of UFO calls from the general public, and spend a large amount of time doing this education work for free for large, for-profit private companies. In this talk, we provide some pointers for satellite operators to educate the general public about the changes that their activities are causing in the night sky.

15:00

CPS-2 Poster Session

15:00

Jessica Heim

A look into preliminary impacts of satellite constellations on amateur astronomers' activities and research

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The advent of large satellite constellations has become a subject of interest and concern for the field of professional astronomy. Increasing work is being done to better quantify the current and potential impacts on various subfields of astronomical research and to identify possible mitigations to reduce data loss and other challenges. However, little research has been conducted with the aim of exploring specifically, the nature and extent of impacts on amateur astronomy activities. In this presentation, I will present findings from surveys distributed to amateur astronomers. The purpose of these surveys was to obtain data that can help to understand both qualitative and quantitative impacts of large satellite constellations on the observations and research of these communities and to inform possible ways forward to minimise adverse effects on amateur astronomy activities.

15:30

CPS-3a: Community Engagement

15:30

All

Community Engagement Hub Open Discussion and Q&A

16:00

CPS-3b: Industry & Technology

16:00

Patricia Cooper

Industry & Technology Hub Welcome & Panel Introductions

16:05

Carissa Christensen

The Rise of SmallSats and Satellite Constellations — Growth and Drivers

16:20

Tim Stevenson

Industry & Technology Hub: Raising Industry Awareness and Aiding Mitigations

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The Industry and Technology Hub of the IAU CPS has a number of functions in providing an interface to the satellite industry — operators and manufacturers (both systems and technology). Firstly, the Hub is an 'attractant' to bring industry stakeholders to the CPS and its Hubs and to promote a common understanding of both the problem of dark and quiet sky and the potential solutions. Secondly, the I&T Hub offers support to industry in a number of ways, including briefings, background documents and active support in the form of Astronomer guides. Thirdly, the Hub meets a need for industry players to share experiences amongst themselves in terms of the efficacy of solutions and how to take dark and quiet sky considerations into account in design, mission planning and operations. Finally, the Hub is promoting the necessary research into further solutions both for the deleterious optical/infra-red effects and into mitigations in the radio wavelengths.

The Hub actively seeks out industry participation, and has been highly successful in attracting major actors and getting them to interact, begin to contribute to wider CPS activities such as observation campaigns and to share the understanding of the threats to ground based astronomy in order to address them.

This contribution provides an update on the work of the I&T Hub and the latest state of play for developments in mitigations.

16:27

Chris Hofer

Amazon Project Kuiper — Incorporating Mitigations from Design

16:35

Maurizio Vanotti

Eutelsat Group’s OneWeb Project — What’s Next

16:42

All

Industry & Technology Open Discussion and Q&A

16:57

Patricia Cooper

Conclusions & Closing Remarks

17:00

END

Time

Speaker

Title

CPS-4: Priorities and Pathways Forward

08:00

Federico Di Vruno

Summary of CPS sessions on August 7

08:30

Connie Walker

Priorities for Volunteer Involvement

09:00

Richard Green

Discussion on Pathways for Implementation

09:30

END