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23rd AMOS conference Maui, US / 27.09.22 – 30.09.22

A systems theory approach for evaluating
the cascading collision potential of orbital shells



Understanding the probability and the impact of cascading collisions in earth’s orbit turns out to be one of the more controversial topics in space sustainability and risk management. A lot of work invested over the past decades and especially in the last years has led to a better understanding of fragmentation and collision processes. The fragmentations and collisions which took place during that time served as real-life examples to validate or falsify model approaches, and to refine them. So far, we have not seen cascading collisions leading to what has been described as the “Kessler syndrome” decades ago. Similar to climate change, it is not possible to determine exactly when the tipping point will be reached, but we know we are moving closer to it every day. Using a systems theory approach, the goal of our research was to enable a perspective which is not meant to be contrary, but rather complementary to existing astrophysics and astrodynamics approaches which mostly care about conjunctions and collisions as risks for single objects, their dynamics and interaction with other single-object items.

We show how we can learn from available data and its correlations rather than feeding Monte-Carlo method results into theoretical models. We show how we can use traffic lane analogies from a system traffic point-of-view rather than from a moving-object perspective only. We show how understanding impacts of internal and external changes to orbital shell systems can provide added value for decision-makers that designing better-than-required criteria as thresholds for space sustainability awards on a per-object basis cannot yield.

We use existing measurement data, collected and assigned to altitude- and time-based systems of space objects, for analyzing the interactions of space objects and their evolution over time. This leads us to parameters describing the risk and the potential of cascading collisions. Other than the collision risk obtained by traditional astrophysics and astrodynamics methods, this cascading potential does not tell something about single object risks, but says something about the overall system, about the likelihood an “infected” object can “infect” further objects. Such potential analyses can be performed for different orbital shells and object types with the cascading potential change over time allowing an interpretation of the past, of the current situation and for future scenarios.

We show that for the calculation of the cascading potential, there is a difference between an object repeatedly meeting the same other object, and an object meeting many different other objects on its daily journey. Like in epidemiology, the risk of spreading an infection in a population is much bigger if there is a bigger exchange between many. (Note that this is different from the other perspective of the individual risk of getting infected.)

The resulting parameters and their variation over altitude and time can be used to identify trends, to assign priorities and, therefore, to support decisions e.g., in Active Debris Removal (ADR) planning, but also for life-time extension and Post-Mission Disposal (PMD) considerations [9]. All of these are important tasks on the way to a sustainable use of outer space by our and future generations, which is the guiding vision to which we dedicate our efforts.



11th #IAASS conference / 20.10.21



Risk assessment of anthropogenic objects in earth orbits today mainly focuses on single object pairs, their risk of collision, fragmentation, and their re-entry forecast.
In domains of environmental care, the combination of system empiric and model approach helps understand the overall evolution within “space as a system”, its population dynamics, the evolving progress, the impact of disruptions and indications of turning points.
Classical risk management targets the avoidance of the catastrophe and the strength of the system’s resilience. Our highly complex, multi-dimensional topic requires a bridging framework to establish a cooperative, holistic and approved management, ensuring visibility and understanding for stakeholders and society.
The Sendai framework provides guidance before, during and after catastrophic events, based on preparations done beforehand. We show that a catastrophe leading to unavailability of space services fulfils similar conditions, and that preparedness and resilience are key elements for a safe and sustainable future in outer space.

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Space2Connect ESA Conference | ESA-ESTEC | 14.10.21


Satellite operators are generating in their daily operation huge amounts of measurement data. The SatcomWeather2 project uses signal quality measurement data from VSAT networks to reconstruct the complete system effects from the uplink via the satellites to the user terminals inclusive the validation of the results. The provided measurements arrived from 33,875 VSAT terminals from two VSAT vendors with 5 to 6 data records per measurement from two different satellites with 6 different beams distributed in 17 RF carriers over a period of three years with time resolution of 5′ or 10′ in two continents in more than 1.3 billion data sets. The SatcomWeather2 project shows a new way of Big Data analysis, including a new way of verification in Big Data projects.

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8th European Conference on Space Debris | ESA/ESOC | 20-23 April 2021


Long-Term Data Analysis for Improved Risk Assessment regarding Orbital Assets

Valentin Eder, Christian Unfried, Space Analyses GmbH


Most of today’s Space Surveillance and Tracking (SST) solutions and their usage scenarios consider risk assessment in the form of forecasting single events on a day-to-day basis, such as supporting collision risk analysis by providing conjunction prediction messages. While this represents a highly adequate quick-response process triggering the appropriate crisis management actions, this approach usually neither considers past events and historical anomaly evolutions nor does it lead to further forecasts beyond the single events in focus.
Big Data (BD) analytics helps approach the problem in a different manner. Like for satellite telemetry and satellite communications, long-term data archives of orbital data and resulting multiple conjunction prediction data can be evaluated under the rules of systemic principles, logical constraints and methodological procedures to reveal insights on highly complex dependencies. These insights are seen as a potential key to performing an assessment of a “global” risk in outer space activities, to describing its history, and – considering relevant scenarios – to forecasting its potential future evolution.
In our presentation, we also discuss the path towards a Space Pandemic Dashboard (as an analogy to current climate change and corona virus visualizations) and how historical data and its analysis can contribute to predicting future evolutions. Like in the relation between weather forecasting and climate analysis, like in the relation between medical status and epidemiological scenarios, the steps described represent the advancing from Space Debris Event Monitoring to Space Debris Risk Management.
We draft the elements for a “global” risk estimation process and attempt to visualize the various risk drivers and their interrelations. When we speak about risk in this context, we need to distinguish between the risk on the pure orbital infrastructure, i.e. the risk on the investment, and the operability of orbital objects including the availability, reliability and integrity of the services realised using these assets, i.e. the operational risk (which, as we know, leads to the business continuity risk).
Our current analyses are performed on the basis of publicly available data such as the TLEs provided by CelesTrak. We shall discuss the advantages and limitations of this current range of data and their sources, and also the advantages and limitations of using further – parallel as well as complementary – data sets. This includes a critical view on the aspects of data integrity, data correctness and data usefulness and present an outline of possible future developments.
We will show how the holistic approach can help use existing as well as emerging technologies and procedures in a broader context, promoting the use of long-term, global data and modelling information. This should become an input for decision making in the governance implementation of political, administrative and economic institutions.
It can serve as an initial contribution triggering further research and discussion in the move from Space Situational Awareness to Space Traffic Management, and from Space Sustainability Guidelines (UNOOSA/UN CUPOUS A/AC.105/2018/CRP.20) to an operational implementation of Security in Outer Space (which ESPI defines as “Protection of the Space Infrastructure against natural and man-made threats or risks, ensuring sustainability of Space activities.”).




#SpaceWatchGL Opinion: How Mega-Constellations Lead to Increased Sustainability Risks in Outer Space

by Valentin Eder

This article looks at the impact of mega-constellations to the collision risk in outer space using the results of a systemic approach to reducing the uncertainty of the ambiguity of actual developments based on conjunction analyses on the example of  SpaceX’s Starlink using TLE data from space-track .


#SpaceWatchGL Opinion: ‘The Rule of Law’ and the Calls for Regulating Space

by Valentin Eder

The actual discourse and the call for regulations (or management) of space traffic seems to miss something fundamental which is the understanding of the ‘Rule of Law’ and the overview in the ‘causal chain’.


SpaceWatchGL Opinion: The Dreams of New Space – Sharing of Profit and Damage in Outer-Space Activities?

by Valentin Eder

The actual (r)evolution in the Outer-Space usage brings also a socio-economic change not sufficiently discussed in the community


#SpaceWatchGL Opinion: Lock Down on All Space Launches!

by Valentin Eder

This article describes – in a non-diplomatic way – the current setting/behaviour of space industry stakeholders and a set of radical, but necessary actions to ensure the long-term sustainability of outer space in the interest of operators, the industry, last but not least, of the global society. This article follows “How Mega-Constellations Lead to Increased Sustainability Risks in Outer Space” published on 7 February 2021 on SpaceWatch.Global.


Briefing the EU institutions

European STM Conference – 3rd meeting of the Preparatory Group: Hearing – 24 March 2021

In the context of the EU STM conference Space Analyses was invited to hold a briefing together with other Non-governmental institutions and the industry.

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Crashs im Erdorbit

Wenn es im Erdorbit kracht.

Radio Broadcast (German) March 2021, 19:05
Austrian Public Radio Channel Ö1

Vor rund einem Jahr irritierte der Blick in Abendhimmel so manchen Beobachter: Eine ungewöhnliche Lichtkonstellation zog sich da über das Firmament, viele helle Lichtpunkte in regelmäßigen Abständen in einer fast perfekten Linie, zu perfekt um natürlichen Ursprungs zu sein. Das sind diese Lichtquellen auch nicht: Das US-amerikanische Raumfahrtunternehmen SpaceX hatte eine weitere Ladung ihrer Starlink-Satelliten in die Umlaufbahn geschickt. Starlink verspricht Internetzugang auf der ganzen Welt, selbst in abgelegensten Gebieten. Dafür sollen bis zum Jahr 2030 insgesamt 42.000 Kleinsatelliten in den Erdorbit gebracht werden. Eine sogenannten Mega-Konstellation, die nach Ansicht des Weltraumanalysten Valentin Eder große Risiken birgt. Schon jetzt finde man im Erdorbit mehr Schrott als funktionierende Satelliten. Je mehr Objekte um die Erde kreisen, desto höher das Risiko weiterer Zusammenstöße. Das hätte nicht nur wirtschaftliche Folgen: Viele Bereiche moderner Gesellschaften sind auf Satellitendienste angewiesen, wie Signale für GPS, Wetterberichte, Fernsehstationen und nicht zuletzt die wissenschaftliche Erdbeobachtung. Valentin Eder erstellt regelmäßig Prognose über Risiken und potenzielle Crashs im Erdorbit und kommt zu dem Schluss, dass das Risiko einer fatalen Kettenreaktion steigt. Warum es im Weltall langsam eng wird, erzählt er in dieser Ausgabe von dimensionen.diskussionen.