2nd Workshop - Atmospheric Impacts of Spacecraft Launch and Re-entry

23 Sept 2025, 09:00 → 25 Sept 2025, 16:20 Europe/Amsterdam

Auditorium (ESTEC)

As part of the ESA Green Agenda and the Clean Space Office, we must drive the design of space products and services towards minimizing the environmental impacts throughout their entire life cycle.

Building on the insights from the first conference on ‘Understanding the Atmospheric Effects from Spacecraft Re-Entry’, the workshop series on the environmental impact of space transportation systems, and continued joint efforts of the AIRL (Atmospheric Impact of Re-entry and Launches) initiative driven with the ESSC, this second workshop focuses on identifying key scientific gaps and formulating urgent recommendations to support further research.

It aims to emphasize the critical importance of collecting real-world data to advance our understanding of the physicochemical processes associated with spacecraft launch and re-entry emissions. With the rapid growth of the space industry and the increasing frequency of satellite launches and re-entries, assessing their atmospheric and environmental impact has become a critical priority. 

Recent findings indicate that anthropogenic metal emissions from spacecraft re-entries could become a major contributor to the stratospheric particle load, exceeding the natural meteoritic influx. Observations from high-altitude aircraft and ground-based facilities have identified metal-rich particles in the stratosphere, raising concerns about their potential role in ozone depletion, atmospheric chemistry, cloud formation, and radiative forcing. The World Meteorological Organization warns ‘’that these interactions are poorly understood...and periodic assessment and critical knowledge gap identification are warranted.’’

This workshop will explore the key scientific, engineering, and environmental issues related to spacecraft launch and re-entry, including:

• Field measurement campaigns – reviewing existing field study findings and exploring future initiatives to detect and analyse aerosols containing launcher and spacecraft-derived particles.
• Chemistry of launch and re-entry emissions – investigating how spaceflight compounds such as nitrous oxide, metal oxides, black carbon, and ablated materials interact with the gases and aerosols already present in the ‘background’ stratosphere and mesosphere, including their potential to catalyse ozone depletion and alter cloud formation.
• Advancements in modelling and laboratory simulations – assessing how experimental and computational approaches can improve predictions of atmospheric impacts.
• Methodologies for integrating atmospheric impacts into life cycle assessments – Evaluating how launchers and spacecraft can be designed to minimize environmental impact.
• Cross-disciplinary collaboration – bringing together experts in atmospheric science, the space sector, and policy to identify research gaps and explore strategies for regulation.

 

As space activities continue to expand, coordinating upper-atmosphere research and data-driven policymaking is increasingly essential. This workshop will provide a collaborative platform for the scientific and industrial communities to align efforts, ensuring that future space missions adopt sustainable and environmentally responsible practices.

We invite researchers, industry professionals, and policymakers to actively contribute to this discussion and play a key role in shaping the future of atmospheric impact assessment in the space sector. 

Atmospheric Impacts of Spacecraft Launch and Re-entry PRIVACY NOTICE - DPNR 2873_..pdf

Pathway_Closing_Knowledge_Gaps_LCA_Ecodesign_STS (002).pdf

Understanding the Atmospheric Impact from Spacecraft Re-entry Workshop Report..pdf

Tuesday 23 September

09:00 Welcome

09:45 Introduction

1 AIRL (Atmospheric Impact of Re-entry and Launches)

Speaker: Mr Serge Flamenbaum (European Space Sciences Committee)

2 Developing the people and skills to address the Space Launch Impact on Climate and Environment (SLICE)

Space utilisation plays a crucial role in understanding climate change, but due to a drastic increase in launch rates, there is an urgent need to understand and mitigate potential environmental impacts of space activities themselves, particularly of launchers. However, large knowledge gaps persist for their operational phase from lift-off to landing/reentry. Here, the largest Global Warming Potential and Ozone Layer Depletion Potential are expected. Especially in the higher atmospheric layers, which are only accessed by launchers, potential impacts of emitted pollutants are amplified by very long retention periods and substance accumulation effects. To investigate the Space Launch Impact on Climate and Environment, SLICE will therefore develop a research and training programme that bridges the current divide between space engineering and climate science to close the gaps that exist in the Life-Cycle Analysis of space launch systems. Thus, SLICE will contribute to advance the science of climate change by investigating the three most pressing research areas of this field: Launch Vehicle Emissions, Atmospheric Interaction & Climate Impact and System Analysis & Design. This will generate actionable insights, on which SLICE will develop solutions to reduce greenhouse gas emissions, accelerate the delivery of the Green Deal and establish an environmentally sustainable access to space. This will not only generate desperately needed novel results, which will enable cutting-edge innovations. It will also satisfy the pressing demand for a new generation of highly skilled and resilient researchers, trained to create and realise these necessary innovations and to develop a natural ecodesign thinking. SLICE is also highly needed to support current policy efforts, including the European Green Deal, ESA’s Agenda 2025, the upcoming EU Space Law and Product Environmental Footprint (PEF) regulations at European level, including the development of PEF Category Rules (PEFCR) for space.

The European Commission selected SLICE to be funded as an Innovative Training Network under the Horizon Europe's Marie Skłodowska Curie Actions. SLICE brings together 30 institutions from 9 European countries in a unique project that will start in January 2026. It is expected that SLICE will have a large community-building impact in the field of space sustainability and, in particular, the atmospheric impacts of spacecraft launch and re-entry.

The presentation will give and overview of the project and present the work plan, with a focus on the cross-disciplinary methodology. Since 18 doctoral candidates will be recruited for SLICE in 2026, the main purpose of this presentation is to make the community aware of these opportunities ahead of the publishing of the job advertisements in January 2026.

Speaker: Dr Christian Bach (Technische Universität Dresden)

3 Meteors and the natural input of material into Earth's atmosphere

In this talk I will briefly cover what we know about the natural input of material into the Earth's atmosphere as well as how to measure and model the meteor phenomena that occurs during this input. This overview will of course not be exhaustive but will aim to provide context to the topics at hand.

Speaker: Daniel Kastinen (Swedish Institute of Space Physics)

4 Space Waste: An update to the human-made atmospheric input inventory

The number of spacecraft in low Earth orbit has strongly risen in the last years due to a generally increased human exploitation of space and specifically satellite mega-constellations. Besides the well-known problems of on-orbit space debris and ground impacts, this has resulted in a strong increase of the human-made mass ablating in Earth’s atmosphere, hereafter named space waste. An updated space waste input inventory is presented compared to the first comprehensive estimation in Schulz and Glassmeier, 2021 (Advances in Space Research, 2021, 67 (3), 1002-1025). The update includes annual input values for the last years and possible future scenarios regarding expected satellite launch numbers. We report overall injected mass as well as elements not previously analyzed. The presented data can serve as a baseline for modelling efforts and help steer towards the most promising future research. As space waste remnants have already been found in stratospheric aerosol particles (Murphy et al., PNAS, 2023, Vol. 120, No. 43, e2313374120) and concrete pathways of e.g. ozone depletion exist, better knowledge of the whole process chain of atmospheric injection to atmosphere effects is critical.

Speaker: Leonard Schulz (Institute of Geophysics and Extraterrestrial Physics, Technische Universität Braunschweig)

5 Understanding Re-entry Pollution: ESA Data, Tools and Campaigns

The growing number of satellite and rocket-body re-entries over the past decade has become an increasing concern for upper-atmosphere pollution. As these objects burn up, they release metals and other compounds that may affect stratospheric chemistry, particle formation, and radiative processes. Despite its importance, the scale and long-term consequences of re-entry emissions remain poorly characterized.
To help address this gap, the European Space Agency (ESA) provides datasets that forecast the number of re-entries expected over the coming decades, considering different scenarios of launch activity and satellite decommissioning. These projections offer a realistic basis for estimating the evolution of metallic pollution linked to space activities. The data can also be further processed with ESA’s DRAMA (Debris Risk Assessment and Mitigation Analysis) tool to estimate ablation rates and temperature profiles during re-entry, delivering valuable inputs for the characterisation of these phenomena.
To further advance the understanding of re-entry physics, ESA is preparing a dedicated observation campaign in 2026, targeting the re-entry of two CLUSTER-II satellites, Tango and Samba. Following the successful 2024 campaign for the re-entry of the CLUSTER-II satellite Salsa, this initiative represents a unique opportunity to collect direct measurements of ablation behaviour, providing critical validation for simulations and supporting our understanding of how pollutants are injected into the atmosphere.
By combining long-term forecasts, process-level modelling, and new observational data, ESA aims to support the atmospheric science community in building a more comprehensive picture of re-entry-induced pollution. This contribution will present available datasets, demonstrate their use within DRAMA, and outline the objectives of the 2026 campaign, with the goal of strengthening collaboration between the space and atmospheric research domains.

Speaker: Silvia Sanvido (IMS Space Consultancy)

11:30 Break

6 Constraining the origins of terrestrial stratospheric solid aerosols over the 1981-2020 period

We study the evolution of the stratospheric solid particle population with time using the longest time series of stratospheric sampling data from the NASA Cosmic Dust Catalogs.

Indeed, in 1981, the NASA Cosmic Dust Program was created to collect and study cosmic dust particles in the stratosphere between 18-20 km over the United States with campaigns running until the present time. The NASA WB-57 and ER-2 (and until 1986 the U-2) aircraft collect these particles on silicone oil covered plates. Particles typically larger than 5 microns are manually selected from the plates and characterized under optical and Scanning Electron Microscopes (SEM). Their elemental composition is measured by Energy Dispersive X-ray Spectroscopy (EDS). Based on these data, the particles are tentatively classified into 4 groups:
• Cosmic (C): originating from asteroids and comets;
• Terrestrial Contaminant Natural (TCN): from stratospheric injection of ash from volcanic eruptions and biomass fires, pollens, spores, salts, etc.
• Terrestrial Contaminant Artificial (TCA): from re-entry of space objects such as satellites, rocket bodies, and space debris;
• Aluminum Oxide Spheres (AOS): from Solid Rocket Motors exhaust.

5070 particles were selected, analyzed, curated and the corresponding data were published in the NASA Cosmic Dust Catalogs, covering the period 1981-2020.

Our work has revealed that the population of TCA in these catalogs has increased in the last 10 years. However, the amount of collected AOS has decreased since the end of the Space Shuttle Program in 2011.

We have developed a digitalization and numerical pre-processing of the EDS spectra of the particles to allow intercomparison between different catalogs. We have explored these digitized spectra with multivariate analysis techniques (Principal Component Analysis) and generated non-linear 2D projections of these multidimensional scatter plots. EDS spectra of natural minerals and pure elements were added in the dataset as references to help the interpretation and to identify particles of similar composition. Finally, an automated clustering was used to identify new compositional groups of particles. Hence, we can better relate these compositional groups to the possible origins of the particles and calculate new statistics. For example, using the ~1000 particles published in Catalog 18, we can separate volcanic ash (similar to Rhyolitic glass) and S-rich volcanic ash, chondritic particles from undifferentiated asteroids and comets, and particles coming from differentiated asteroids, from spacecraft paints (Cd/Zn-rich), from electronics (Cu/Si-rich), satellite structures (Al-rich with other metals), solid rocket motors (aluminum oxide spheres) and other.

Speaker: Mr Quentin Taupin (Centre National d'Etudes Spatiales (CNES), Toulouse, France)

7 Shining light on pollution at the Edge of Space: Lithium in the mesosphere

Space emissions are expected to form a new source of metals in the mesosphere but have not yet been systematically measured so far. We tuned a lidar at our site at Kühlungsborn/Germany (54°N, 12°E) to observe the lithium metal layer, a region between about 80 km and 100 km altitude in the mesosphere and lower thermosphere (MLT). The natural metal layer originates from meteoric ablation and contains various species that are often well understood, like Na, K, Fe, Ni, etc. Lithium is an important target species for studying space emissions into the atmosphere because of its low share in cosmic dust compared to its use in the space industry. We initiated lithium lidar observations in August 2024 and found Li densities of up to ~1.5 atoms/cm³. During the following soundings until February 2025, the lithium abundance showed a seasonal increase from summer to winter by up to a factor of five. First simulations of the natural lithium layer using the WACCM-Li model successfully reproduced most of our observations.
On the night of 19/20 February 2025 at 00:21 UTC, suddenly a thin layer with a lithium density of up to ~30 atoms/cm³ appeared in the lidar beam. Back-trajectories revealed that the probed air mass travelled within ~20 h from a location west of Ireland, where a Falcon 9 upper stage entered the atmosphere, to our site. Even if the ablation of space debris is most significant below the natural metal layer because of the lower entry speed compared to cosmic dust particles, this rocket part started ablation around 100 km altitude because of the shallow entry angle of this uncontrolled re-entry.
Besides re-entry, rocket launches impact the atmosphere by, e.g., emission of water vapor and different kinds of aerosols. We will present our lithium observations and provide an outlook on our new lidar systems dedicated to studying launch emissions and re-entry ablation in the MLT.

Speaker: Michael Gerding (Leibniz Institute of Atmospheric Physics)

12:40 Lunch

8 Spacecraft Reentry Metals in the Stratosphere

Measurements of aerosol particles in the stratosphere show that metals that were vaporized during the reentry of rocket boosters and satellites accumulate in the stratosphere. These metals are incorporated into natural sulfuric acid particles in the stratosphere. Over 20 elements from reentry were detected and were present in ratios consistent with alloys used in spacecraft.
We are providing an update on our understanding of these metals in the stratosphere. Particles in the stratosphere with both meteoric and spacecraft metals are slightly larger than those with only meteoric metals. Extended laboratory calibrations are allowing us to have better estimates of some of the previously published metals and to quantify several more metals. One example of a preliminary result is that the relative amounts of tin and lead are consistent with electronics as the source of those metals.

Speaker: Daniel Murphy (Purdue University and NOAA)

9 The Impact of Deorbiting Spacecraft on Stratospheric Particles

In response to an increase in launches and crowding of Low Earth Orbit (LEO), one solution that has been suggested is to increase the deorbiting of defunct spacecraft. As a result, recent estimates suggest a five-fold or more increase in the number of objects re-entering the atmosphere in the 2020s over the average since the 1970s. While deorbiting material will help clear LEO, the atmospheric impact of this material has not yet been extensively studied.
The first unequivocal observations of ablated spacecraft particles in the stratosphere by Murphy et al. (2023) provides a starting point for studies of atmospheric impacts. The particles sampled by Murphy et al. were shown to be internal mixtures of meteoric and spacecraft metals within a sulfuric acid and water matrix. The role of meteoric “smoke” particles acting as condensation sites for sulfuric acid and water as they sediment from the mesospheric source region has been established. The results of Murphy et al. point to this also being the case for spacecraft materials. Several questions remain, including: How much of each component is present? What form does it take? What is the phase state of each component? The answers to these questions are critical to understanding atmospheric impacts such as chemical reaction rates (e.g., ozone loss) as well as nucleation potential. (e.g., polar stratospheric and cirrus cloud formation rates).
This presentation will discuss the current state of experiments on the solubility behavior and phase state of meteoric and spacecraft-derived metals in sulfuric acid-rich particles mimicking the conditions of the stratosphere. Expansion of this work to studies of the heterogeneous chemistry impact of these particles on stratospheric ozone and the ice nucleating efficiency of metal oxides and sulfates under upper tropospheric and lower stratosphere conditions will also be described.

Speaker: Prof. Daniel Cziczo (Department of Earth, Atmospheric and Planetary Sciences, Purdue University)

10 A two-model study of the climate impact of present and future space flight

Rocket launches have clear local impacts on atmospheric composition as well as on global climate, and the number of launches to Low Earth Orbit (LEO) from space agencies and commercial space activities are projected to greatly increase over the next few decades. Better understanding of the broader impacts on air quality, stratospheric ozone, and global climate, under plausible frequency and technological scenarios, including reusable rockets, are essential to fully appreciate their potential effects. Depending on the future path of space exploration and utilization, the global rate of orbital launches is projected to accelerate and include an increasing number of heavy lift launch vehicles, which would result in much higher rocket engine emissions. Spaceflight is largely unregulated, a situation that could change in the future as the rate of launch emissions increases. Detailed studies of the impacts of emissions from all phases of space flight, from launch to reentry and in all layers of the Earth’s atmosphere, are necessary.
We have studied the impact of a range of launch scenarios and pollutants in the atmosphere, using two climate models: GISS ModelE, and CESM WACCM. The two models produce very robust results in terms of the climate effects of rocket launches in the future atmosphere, which provides additional confidence to our findings. We simulate a very consistent climate signal of increased stratospheric water vapor due to the warming effect rocket-induced black carbon (BC) has on tropopause temperatures, which allows water to leak from the troposphere to the extremely dry stratosphere. Additional impacts on ozone and other greenhouse gases like methane, as a result of the changed photochemistry due to the enhanced water vapor in the stratosphere, are also identified. Payload-specific launch scenarios, including those guided by current projections from private space flight companies, on top of the ones studied thus far, are also under development

Speaker: Dr Kostas Tsigaridis (Columbia University)

11 Ablation of Space Debris and Chemistry on Aluminium-containing Particles

The ablation of de-orbiting satellites and rocket motors in the middle atmosphere (30 - 100 km) injects Al vapour which immediately forms AlO and AlOH. Polymerization of these molecules most likely forms aluminium hydroxide (Al(OH)3) particles. This presentation will first describe a new ablation model of an Al alloy surface during atmospheric entry, which was tested against observations of the uncontrolled reentry of a Falcon 9 rocket in February, 2025. We will then predict the probable injection rate profiles of Al(OH)3 particles resulting from the ablation of satellites and rocket motors. Quantum chemistry (electronic structure theory) calculations will then be used to explore the probable heterogeneous chemistry of the chlorine reservoir species HCl and ClNO3 on the Al(OH)3 surface in the stratosphere, including the surface-catalyzed photodissociation of HCl. These results have been included in the Whole Atmosphere Community Climate Model (WACCM), coupled to the Community Aerosol and Radiation Model for Atmosphere (CARMA) sectional aerosol model. The model results will be described in a companion presentation.

Speaker: John Plane (University of Leeds)

15:40 Break

12 Impacts of space Debris ablation on Earth’s Atmospheric System

The re-entry of spacecraft from low Earth orbit produces an anthropogenic influx of metals such as aluminium, lithium, and copper which already exceed natural background levels. We present the results of a modelling study to predict the atmospheric impact of Space Debris Particles (SDPs), composed of Al(OH)3 nanoparticles which form from ablated aluminium, using the Whole Atmosphere Community Climate Model (WACCM), coupled to the Community Aerosol and Radiation Model for Atmosphere (CARMA), a sectional aerosol model. The effects of catalytic chlorine activation on the surface of the SDPs and SDP-nucleated polar stratospheric cloud formation are considered at present day SDP levels and predicted future levels. We predict significant changes to stratospheric ozone if the predicted increases of SDPs occur, and identify the shape of SDP particles and their interaction with the Junge layer sulphate droplets as key unknowns in this field.

Speaker: Dr Joanna Egan (University of Leeds)

13 Investigating the Potential Atmospheric Accumulation and Radiative Impact of the Coming Increase in Satellite Reentry Frequency

Construction of numerous satellite megaconstellations in the low Earth orbit (LEO) (150km - 2,000 km) is projected over the coming decades. Estimates suggest that the number of satellites in an LEO could exceed 60,000 by 2040. The increase in the annual mass flux of anthropogenic material into the upper atmosphere as a result of maintaining these megaconstellations could rival the natural occurring meteoric mass flux. Little is known about the aerosols that will be produced by reentry vaporization, which makes estimating the associated impacts on the atmosphere and ozone difficult. Aluminum is a primary satellite component that will likely be emitted during reentry vaporization. In this study, we use the Whole Atmosphere Community Climate Model (WACCM), coupled with a sectional aerosol microphysical model (CARMA) to simulate a reentry emission of 10 Gg/yr. We assume that all aerosols released is aluminum oxide (Al2O3). This level of Al2O3 emission is consistent with expected megaconstellation growth by 2040. We investigate how the location of atmospheric accumulation, aerosol size distribution, and radiative properties of reentry Al2O3 impacts the middle-to-upper atmosphere. We find that depending on reentry latitude and aerosol size distribution, a 20Gg-40Gg stratospheric burden of alumina aerosols accumulates poleward of 30 N/S between 10 and 30 km within 1-2 years after the start of emissions. Small but statistically significant changes in mesospheric heating rates lead to 1.5 K-temperature anomalies in the mesosphere and the stratosphere at Southern Hemisphere high latitudes. These temperature anomalies are accompanied by a 10% reduction in wind speed in the Southern Hemisphere polar vortex, leading to a weaker springtime ozone hole. Some reentry scenarios also experience a strengthening of the Northern Hemisphere polar vortex.

Speaker: Christopher Maloney (Cooperative Institute for Research in Environmental Sciences, University of Colorado)

14 Mass Fluxes of Space Debris upon Demise in the Atmosphere

This presentation showcases a method for determining the high-altitude atmospheric injection of anthropogenic objects that reenter from Earth's orbit and estimating the chemical species generated during reentry. Uncertainties are quantified.

Reentry data from ESA's Space Environment Report is used to analyze annual trends, showing a record-breaking launch and reentry mass in 2024 of over 2200 tonnes and 490 tonnes, respectively. The accumulation of chemical compounds of anthropogenic origin in the mesosphere is compared against natural levels. It is concluded that the amount of aluminum that reentered the atmosphere originated from satellites and upper stages of launch vehicles surpassed, for the first time in 2024 and with a level of confidence of 95 %, that of meteoroids.

The methodology presented can be applied to estimate the atmospheric burden of individual chemical species originated during reentry. The approach to uncertainty quantification can be used to highlight current knowledge gaps.

Speaker: José Pedro Ferreira (University of Southern California)

17:00 Workshop Disussion

Wednesday 24 September

08:30 Break

15 Responsible Disposal of Non-Operational Space Objects: International law, Transboundary Pollution and the Role of Domestic Environmental Impact Assessments

With the rapid development of the space sector, facilitated by small satellites and new launch technologies, there is growing awareness of the terrestrial impact of space activities and the limitations in previous conceptualisations of ‘space sustainability’. This presentation explores the extent to which international law requires states to consider the potential environmental consequences of the re-entry of space objects into the Earth’s atmosphere at the end of their operational life and how these concerns are being addressed, if at all, in national licensing regimes. We contrast approaches in the UK, USA and France, with a particular focus on the incorporation of risk assessments and EIAs; whether the terrestrial environmental impact of space object disposal is considered, possibly as part of a broader life-cycle analysis; and co-operation with other states and the international community in sharing information and engaging in collaborative research. We also consider the EU’s recently published draft Space Act and the potential for regional regulation to address some of the limitations inherent in both international and national regimes.

Speaker: Dr Rachael Craufurd Smith (Edinburgh Law School)

16 Scientific gaps and possible pathways to address them

Large knowledge gaps persist in understanding how gaseous and particulate emissions from space activities (rocket launches, space debris demise during reentry) influence the middle atmosphere. The main concerns are their potential impacts on the ozone layer and on climate. Uncertainties span nearly all stages of the atmospheric lifecycle of these pollutants: their initial release, physicochemical transformations in launch and re-entry plumes, global transport and dispersion, and ultimately their chemical and radiative effects during transit through the atmosphere.

Addressing these gaps requires a multi-faceted approach. First, internationally coordinated efforts are needed to collect field data, preferably in situ, on launch and reentry plume composition, as well as on space activities pollutant levels in the background middle atmosphere. Second, laboratory experiments are essential to examine critical physicochemical processes, for example those occurring during re-entry demise. Third, plume, mesoscale, and global models must be refined to more accurately represent the complex microphysics and chemistry of these pollutants.

This talk will provide a brief overview of knowledge gaps and outline possible pathways to address them.

Speaker: Dr Slimane Bekki (LATMOS)

17 Characterization of Stratospheric Aerosols Amid Rising Satellite Re-entry

Stratospheric aerosols play a critical role in atmospheric chemistry and climate. They influence stratospheric chemistry through heterogenous reactions- such as those impacting ozone depletion- and affect the Earth’s energy balance through radiative forcing. Recent research reveals that stratospheric aerosols exhibit a far greater compositional and morphological complexity than previously assumed. With the anticipated increase in satellite launches over the coming decades, debris from satellite re-entry has emerged as a potential new and significant influence on the composition and morphology of stratospheric aerosols.
Here we present the analysis of stratospheric aerosol samples collected by Harvard’s Mini-MOUDI, a cascade impactor that collects aerosols for offline analysis. Using advanced analytical techniques, such as STXM-NEXAFS and CCSEM-EDX, we characterize aerosol elemental composition, organic content, and particle morphology. Recent observations from the 2023 SABRE (Stratospheric Aerosol processes, Budget, and Radiative Effects) campaign highlight the diversity in stratospheric aerosol composition and morphology. These measurements provide a valuable baseline for understanding present-day stratospheric aerosols and set the stage for detecting changes with increased satellite re-entry. This approach enables us to target specific elemental content, assess organic matter contributions, and monitor shifts in particle composition and morphology over time.

Speaker: Sophie Abou-Rizk (Harvard University)

10:00 Break

18 An initial analysis of aluminium vapour production in spacecraft demise

This investigatory piece of work was commissioned by the UK Space Agency and provides a starting point for the assessment of likelihood of, and mechanisms behind, the production of very small particulate phase aluminium which can potentially reside in the atmosphere for a long period of time. This constitutes an assessment of the likelihood of significant vaporisation of aluminium from a range of particle sizes at different release altitudes. This work is performed using drag and heating algorithms which are standard in aerodynamic analyses and destructive re-entry tools.

The assessment of the potential vaporisation of aluminium oxide, or oxide-coated aluminium particles, suggests that it is possible that a significant fraction of the aluminium mass from spacecraft could be vaporised, and thus deposited in the atmosphere as nanometre sized aluminium oxide particles. However, this work also shows that this is highly dependent upon a number of assumptions, not least the particulate surface properties, and that the effect could, potentially, be relatively small.

The critical aspect demonstrated in this work is the dependence on the catalycity of the particle surface. A low catalycity ceramic (aluminium oxide) surface would heat significantly less than a high catalycity surface as is observed for aluminium objects (with oxide layer) in wind tunnels. An improved understanding of the heat fluxes which are received by aluminium particles is critical to the understanding of the vaporisation potential.
It is also worth noting that this analysis has assumed that the vaporisation behaviour of aluminium oxide is dominant as this forms the outer layer of the particle. It is feasible that there is some aluminium metal vaporisation. This would serve to increase the material vaporisation as the vaporisation temperatures are lower for the unoxidized material.

The size distribution of produced particles is also a critical aspect of the analysis. It is known that relatively large particles are produced in spacecraft demise, but there is a possibility that these will break-up due to the high speed flow. It is not clear how many of the particles escape the wake of the demising object, and the analysis here assumes that all the particles reach the free stream flow where the heating is more extreme.

Consolidation of these findings in ground testing is required to increase confidence in the modelling.

Speaker: James Beck (Belstead Research Ltd)

19 The Space Materials Ablation Simulator (SMASI): first results on the thermal ablation of aluminium alloys.

SMASI is a table-top simulation chamber developed at IAA-CSIC from a forerunner instrument at the University of Leeds known as MASI (Meteor Ablation Simulator). The new instrument is designed to perform thermal ablation experiments with space debris analogs, with the objective of studying the evaporation of their elemental constituents upon atmospheric re-entry and the subsequent formation of molecules in the presence of atmospheric gases. SMASI has improved capabilities of measuring simultaneously two chemical species ablated from the samples by laser induced fluorescence and recording videos of the evolution of the samples while controlling the ablation temperature. In addition, SMASI has the ability to detect polyatomic molecules downstream of the heated sample by mass spectrometry, which provides a glimpse of the chemistry that occurs under atmospheric conditions. We have performed so far experiments using different aluminium alloys (e.g. AA1421, AA6061, AA7075) with the aim of understanding the oxidative ablation of aluminium under atmospheric re-entry conditions as well as the evaporation of mayor components of these alloys such as lithium and copper. It is worth pointing out that although extensive literature on the ignition and combustion of nano- and micron-sized aluminium partiles and aluminium foils exist, experiments looking at evaporation under relevant atmospheric heating rates, oxygen concentrations and particle sizes have not been reported yet. Similarly, the fate of aluminium atoms beyond its fast bimolecular reaction with oxygen had not been investigated. Here we show that oxygen starts playing a role in hindering aluminium evaporation at concentrations higher than those typical at 60 km altitude, but this is dependent on the heating rate. For high heating rates (50 ºC/s) oxygen barely plays a role in preventing evaporation, while at lower rates (4 ºC/s) the effect of the oxide layer is clearly distinguished as a succession of aluminium bursts caused by oxide shell cracking. The onset of aluminium evaporation occurs around 1300 ºC and is determined by the vapour pressure of aluminium. The main product of atmospheric chemistry is aluminium hydroxide (not alumina, as commonly assumed). For lithium, we observe that evaporation starts around 800 ºC and lithium depletion is almost complete by the time aluminium starts evaporating. These observations carry important consequences for the ablation of Li-Al alloys. The relatively high threshold for aluminium evaporation most likely determines the fraction of this metal that partitions to the gas phase, considering the relatively low apparent temperatures observed during real re-entries. Aluminium hydroxide is potentially more effective in activating chorine when taken up by stratospheric aerosol. The low-threshold, fast evaporation of lithium from alloys implies that anthropogenic lithium from re-entries overlaps with the natural lithium layer, which suggest that Li lidar could be use to track the antropogenic mass input globally. The potential effect of lithium and copper content on aluminium evaporation is currently under investigation. The datasets generated in these simulations can be used to fine tune re-entry break-up simulation codes.

Speaker: Juan Carlos Gómez Martin (Instituto de Astrofisica de Andalucía IAA-CSIC)

20 Experimental Approach for the Assessment of Particle Formation from Re-entering Spacecrafts

There is a significant lack of knowledge about the impact of the ever-increasing number of satellites that are supposed to demise during re-entry to the upper atmosphere. Although the upper atmosphere faces more than 10 kilo tons of interplanetary dust every year, the main contributor from satellites being aluminum is only a minor constituent of micrometeoroids [1]. The impact of this new trace element to the atmospheric behavior is hardly investigated so far.

Current theories assume that molten or evaporated aluminum presumably oxidizes immediately due to the high abundance of reactive atomic oxygen in the upper atmosphere. Either the reaction leads to gaseous aluminum monoxide (AlO) or solid aluminum oxide (Al2O3) particles are formed. At approximately 70 km we detected spectral signatures of AlO during the re-entry airborne observation campaign of the CYGNUS-OA6 re-entry in 2016 [2]. The formation of solid aluminum oxide (Al2O3) particles is discussed in literature [3] [4] [5]. In our group, we are trying to experimentally evaporate aluminum and detect the paths toward Al2O3 particles by suitable diagnostic means.

In the plasma wind tunnels at the Institute of Space Systems (IRS), University of Stuttgart, these experimental simulations are performed. In a series of experiments the evaporation of aluminum was observed using different experimental setups. In a very first setup, solid aluminum was injected, the result of which is that only larger molten droplets are released from the solid. A second setup consisted in injecting aluminum powder directly into the free jet using a powder feeder. The powder could be observed, but a meaningful diagnostic method was not possible. By using an additional baffle plate further downstream allowed the probably molten aluminum particles to attach to the plate and react further with free flying aluminum in the hot air plasma. This resulted in spectral signatures similar to what was seen in the airborne observation campaign. In a further setup, a sample of aluminum powder cured in epoxy resin was placed in the plasma flow, which again ablated, leading to the evaporation of the aluminum powder. In this setting, the formation of AlO was observed by acquiring spectra of known AlO bands were acquired.

In this presentation, we will provide further insight into the just started experimental work aiming at developing an experimental setup to study the processes which occur after the satellite’s demise. These processes are of utmost importance to develop an understanding of the environmental impact of the ever increasing number of re-entering satellites.

Bibliography
[1] L. Schulz und K.-H. Glassmeier, „On the anthropogenic and natural injection of matter into Earth's atmosphere,“ Advances in Space Research, pp. 1002 - 1025, 2021.
[2] S. Loehle, M. Eberhart, F. Zander, A. Meindl, R. Rudawska, D. Koschny, J. Zender, R. Dantowitz und P. Jenniskens, „Extension of the Plasma Radiation Database PARADE for the Analysis of Meteor Spectra,“ Meteoritics and Planetary Science, 2021.
[3] A. Jain und D. Hastings, „Global Climate Effect from Space Debris Reentry: Engineering and Policy Implications“.ASCEND 2023.
[4] C. M. Maloney, R. W. Portmann, M. N. Ross und K. H. Rosenlof, „Investigating the Potential Atmospheric Accumulation and Radiative Impact of the Coming Increase in Satellite Reentry Frequency,“ Journal of Geophysical Research: Atmospheres, 2025.
[5] S.-H. Park und P. Leyland, „Re-entry survival analysis and ground risk assessment of space debris considering by-products generation,“ Acta Astronautica, pp. 604-618, 2021.

Speaker: Dominik Kuenstler (High Enthalpy Flow Diagnostics Group (HEFDiG), Institute of Space Systems (IRS), University of Stuttgart)

11:10 Break

21 METAL mission: Assessment of anthropogenic pollution by measuring ionospheirc metallic ions

Although the ablation of re-entering space waste is expected to take place mainly in the mesosphere, and some metallic species must have been significantly (>10%) contaminated anthropogenic origin, no measurement has been made such contamination in the mesosphere because it is too high to fly balloons, because no adequate mass spectrometer for low-altitude sounding rocket has been developed to measure high pressure environment in the mesosphere, and the remote sensing method can measure only the major metallic species. Considering the upward mesospheric convection that carries even metallic atoms that are originated from the meteoroid ablation, the best measurement method to estimate the current level of contamination is to measure them in the ionosphere, together with balloon observation in the stratosphere.

The METAL mission (submitted for mini-F call) aims such measurements. The required specification of the mass spectrometer is already available, by which more sciences on the metal dynamics, 3D ionospheric, and ionospheric chemistry can be performed by slightly increasing the apogee of the satellite. In the workshop, the requirement for instrument specification, satellite, and orbit are presented, as well as the other science with such a mission.

Speaker: Masatoshi Yamauchi (Swedish Institute of Space Physics, Kiruna)

22 Space micro- and nano-debris measurements in LEO

Cosmic dust has been measured in situ near the Earth and in interplanetary space, using different types of dust detectors and on various space missions. In situ dust detectors are designed towards specific key measurements to be taken (e.g., composition, velocity, dust flux, surface charge) and according to mission requirements and available resources. Low-resource detectors are usually the "dust counters", and more sophisticated detectors can measure dust elemental composition (i.e., time-of-flight mass spectrometers based on dust impact ionization) eventually combined with a trajectory grid.

Measuring the natural influx of cosmic dust from in space (i.e., no atmospheric bias) can be important for studies of the upper atmosphere in order to define a baseline with respect to the influx of space debris of all sizes, in terms of number count, mass flux, velocity and composition. Dust instruments can also be applied to directly measure space micro and nano-debris in Low Earth Orbit. Measuring the elemental composition of space micro-debris, together with their orbital velocities and locations would yield an independent measurement of the chemistry and the influx of anthropogenic space material into the Earth's atmosphere. These data (with their own biases) can be used in parallel with data from spacecraft and rocket design.

In this talk we elaborate on the dust detection techniques and how they could be used to support the studies of the impact of spaceflight on the upper atmosphere. We also emphasize the interesting case of space nano-debris particles, from LEO to the upper atmosphere.

Speaker: Dr Veerle Sterken (ETH Zürich)

23 Dust detection during the MAXIDUSTY-2 rocket campaign from Andøya in July 2025

The Earth’s mesosphere, especially at the altitude between 80 and 90 km, is the region where the cosmic dust and meteoroids that constantly enter the atmosphere ablate and re-condense to form nanometer-size dust particles, the so-called meteoric smoke particles (MSPs), that remain in the mesosphere and lower thermosphere for some time. The MSPs are believed to play an active role in the physical process of producing several mesospheric phenomena, such as noctilucent cloud, polar mesospheric summer echo, and probably polar mesospheric winter echo, by contributing to the formation of icy particles. However, little is known about the characteristics of MSPs including their composition and size distribution, and their incorporation in the ice particles. Even more uncertain is the role of space debris in the formation of solid, refractory particles at these altitudes.
MAXIDUSTY-2 rocket (MXD-2) was launched on 5th July 2025 with the aim of studying the mesospheric dust in relation to cosmic dust and ionospheric conditions. MXD-2 was launched from Andøya Space, Norway, to make in-situ measurements at altitudes between 70 and 110 km. During the flight three different types of dust detector onboard the rocket, DUSTY, MUDD, and SPID, performed in-situ measurements of charged dust. Other instruments measured the surrounding plasma and neutral components. In addition, a sample collection of mesospheric dust particles was attempted during the campaign with two types of sample collectors, including the newly developed MESS instrument from UiT. The instruments functioned properly, and the recovery was successful.
In this presentation, we briefly introduce MXD-2 and present some preliminary results from the measurements of the UiT dust instruments that are relevant for the studies of solid dust particles in the atmosphere. An overview of the MXD2 project and campaign will be provided later. The project is funded by ESA PRODEX, it involves research institutions from Sweden, Germany and Norway, the Mobile Rocket Base of the German Aerospace Center, and the Andøya Space Center in Norway.

Speaker: Mr Yoshihiro Yokoyama (Institute of Physics and Technology, UiT, The Arctic University of Norway, Tromsø, Norway)

24 Atmospheric Composition in the Constellation Era – The AC2E Initiative (2028 – 2038)

Until 2040, more than 60.000 new satellites are predicted to be launched into orbit. The constellation era will go in hand with an increasing amount of space debris burning up in the Mesosphere / Lower Thermosphere (M/LT), a layer in the upper atmosphere, roughly spanning 50 to 120 kilometers above Earth's surface. As the number of rocket-launches and satellites in orbit grows, so does the amount of space junk re-entering the atmosphere. When this debris decays in the MLT region, it releases various pollutants, including aluminium oxides and soot. These pollutants can alter the chemistry and temperature of the mesosphere, potentially affecting the ozone layer and the overall climate. The metaphor "new ocean" underscores the MLT's emerging role as a critical region for environmental monitoring and research, much like the deep ocean is for marine studies.
The “AC2E” initiative is an international collaboration effort targeting advancement in specific, fundamental issues in space and earth science based upon sounding rockets as experimental platform. The concept was conceived and developed by Andøya Space (ASP), Esrange/SSC and DLR MORABA. Sounding rockets offer unique experimental conditions for in-situ measurements in atmospheric regions, that cannot be reached by other means. Furthermore, they are cost-effective, flexible and can provide high-resolution data on atmospheric conditions that are difficult to obtain from ground-based observations or satellites.
The main aim for AC2E is to set up a repetitive monitoring program providing measurements in the M/LT region at regular intervals by any means possible, but in a systematic and standardized way. This is intended to provide the scientific community with a robust data set for research into the effects on the atmosphere. In addition, the research results will provide the regulatory authorities with relevant background information for decision-making, based on data that is as unbiased and unaltered as possible.
The projected timeframe of 2028 to 2038 is specifically chosen in order to align the initiative with the upcoming Solar Cycles 26 and 27, which have a large influence on the dimensions and characteristics of Earth’s atmosphere and its interaction with space objects.

Speaker: Dr Kathrin Schoppmann (German Aerospace Center (DLR), Mobile Rocket Base (MORABA))

13:00 Lunch

25 FIREWALL – Concept and plans for atmospheric measurements of rocket plumes, including in-situ and remote sensing

The cadence of orbital launches has risen significantly in the past five years from about 100 to more than 250 events per year. This unprecedented growth is expected to continue at a 15% average annual rate. While there are existing and developing inventories for launcher emissions, they lack validation from atmospheric observations. Assumptions that would need verification are exhaust composition, formation of soot, afterburning effects including consumption of unburnt fuel and nitrogen oxides for-mation, and the immediate and downstream impact on atmospheric composition and radiation budget, especially on the ozone concentration. This information is essential to assess the environmen-tal and climate effects of space transport in the framework of life cycle assessment.
Within ESA’s FIREWALL project, several institutes of the German Aerospace Center (DLR) jointly ex-plored the state of the art, open questions, opportunities, requirements and challenges associated with atmospheric measurements of rocket emissions. Various observational platforms were considered, in-cluding aircraft, satellites, sounding rockets, balloons and ground-based instruments, each with their capabilities and focus areas. Research aircraft provide ample instrumentation and high flexibility of the flight path to sample both fresh and aged emission plumes, including the ambient atmospheric state and cloud effects, at altitudes up to the lower stratosphere. There have been earlier deployments, while expertise from the aviation world is expected to enable more precise and targeted observations. Ad-vancements In point source detection from satellites may be useful to sample whole column emissions of nitrogen oxides, carbon monoxide and carbon dioxide globally.
With the developed concepts of operations, FIREWALL should enter a second phase encompassing the demonstration of airborne measurements during an orbital launch. The mission should join forces of the leading international partners in the fields of atmospheric measurement platforms, instrumenta-tion and modelling. Target launchers can be current and development vehicles, including the emerging microlaunchers, with representative up-to-date propulsion technology. The observational capabilities are also suitable to study effects of powered decent of first stages and of re-entry emissions from de-orbiting material.

Speaker: Dr Andreas Marsing (DLR)

26 Altitude Simulation System

Speaker: Mr Hendrik Behler (DLR)

27 Stratospheric Balloon Platforms for Atmospheric Research: B2Space’s micro-HABS and HABS Capabilities

B2Space has developed innovative High-Altitude Balloon Systems (HABS and micro-HABS) that deliver unique capabilities for atmospheric research at altitudes up to 37 km. Designed to complement satellites and ground stations, these platforms enable direct sampling and in-situ measurement of greenhouse gases, pollutants, aerosols, and particulate matter.

A defining advantage of micro-HABS is their rapid deployment: missions can be planned and executed within hours, allowing scientists to respond to specific events or weather windows. Their low cost enables frequent launches, creating dense time-series datasets and improving understanding of stratospheric processes. Larger HABS platforms, with greater endurance and payload capacity, provide complementary opportunities for multi-instrument campaigns and long-duration measurements.

Both systems feature modular designs for quick sensor integration and have already been applied in Earth observation and environmental monitoring.

This presentation will highlight B2Space’s recent projects, ongoing developments, and new opportunities for collaborative science

Speaker: Mr Valentin Canales (B2Space)

28 Dawn Aerospace

Speaker: Mr Stefan Powell (Dawn Aerospace)

29 Zephyr

Speaker: Pierre-Antoine Aubborg

15:40 Break

30 Space Forge

Speaker: Mr Neil Monteiro (Space Forge)

31 Atmospheric Re-entry

Speaker: Mr Stephan Schuster (ESA)

17:00 Workshop Disussion

Thursday 25 September

08:30 Break

32 Assessment of Emissions of Orbital Launches and Rocket Body Re-Entries 2019-2024

Within 2019-2024 the number of successfull orbital launches went from 97 in 2019 to 255 in 2024 (21% p.a.) while the number of rocket stages re-entries went from 77 to 257 (28% p.a.). This growth comes with the risk of unknown effects on climate and ozone.
In order to contribute to a better understanding of the impacts, the University of Stuttgart has used its Open Source codes Launch Emission Assessment Tool (LEAT) and Re-entry Emission Assessment Tool (REAT) to individually calculate the emissions from rocket launches and re-entries of upper stages from 2019-2024 to build up an inventory.
As part of the presentation, this inventory will be presented.
The focus will be on the type and number of different species, including ones which were not previously discussed, and their effects and distribution. The uncertainties that the calculation of emission and these inventories currently have will also be discussed.

Speaker: Jan-Steffen Fischer (University of Stuttgart, Institute of Space Systems)

33 Tracker of emissions of air pollutants and CO2 from spacecraft launches and re-entries

All rocket launches and re-entry events produce large quantities of pollutants and greenhouse gases that deplete stratospheric ozone and alter climate in ways synonymous with proposed geo-engineering aerosol injection strategies. There are no regulatory incentives to track these emissions. Annual emissions are orders of magnitude less than Earth-bound sources, but pollutants persist far longer, causing greater harm per mass unit emitted. We have developed an online tracker of emissions from rocket launches (https://maraisresearchgroup.co.uk/launch_emis.html) and object re-entries (https://maraisresearchgroup.co.uk/reentry_emis.html) using the data gathering and quality checks detailed in Barker et al. (https://www.nature.com/articles/s41597-024-03910-z, 2024). The tracker is for 5 years (2020-2024) covering the onset and rapid growth in megaconstellation missions. We find with our emissions tracker that in just 5 years, propellants used to launch megaconstellation missions has surpassed propellant use by all other kinds of missions. Black carbon (BC) particle emissions from all mission types, dominated by rocket launches, but also including re-entry ablation of carbon-containing composites and resins, has increased 3-fold since 2020. Material re-entering unablated, calculated via mass conservation, has increased almost 2-fold since 2020, posing a risk to people and littering the oceans. Independent data to validate the inventory is exceedingly rare and limited to the Stratospheric Aerosol processes, Budget and Radiative Effects (SABRE) 2023 high-altitude aircraft campaign measurements of 2 intercepts of a kerosene-fuelled Falcon 9 rocket plume, the overwhelmingly dominant rocket launching megaconstellations. We find that the vertically-resolved emission indices used to construct the inventory assume more rapid decline in rocket plume combustion efficiency with altitude than is measured, as the indices rely on outdated data from US Space Shuttle era solid rocket motors. This affects the vertical distribution of launch emissions of BC, nitrogen oxides, carbon monoxide, and carbon dioxide, as all depend on the combustion efficiency or afterburning in the rocket plume. More in-plume measurements at a range of altitudes within aircraft flight ceilings are critically needed to constrain combustion efficiencies for the range of propellants used by the space sector. Many other challenging to quantify uncertainties exist, such as the chemical composition and size distribution of metal oxides produced during re-entry ablation. The tracker is undergoing sustained development to enable near-realtime inclusion of launch and re-entry emissions and to embed new information from re-entry ablation models, laboratory experiments, and measurement campaigns led or supported by ESA.

Speaker: Eloise Marais (University College London)

34 Radiative Forcing and Ozone Depletion of a Decade of Satellite Megaconstellation Missions

Satellite megaconstellations (SMCs) are driving a rapid increase in rocket launch and re-entry rates, emitting pollutants throughout the atmosphere. The environmental cost of SMCs lacks characterization to determine the need for regulation. We utilize a global 3D emission inventory of recent (2020-2022) space activity which distinguishes SMC and non-SMC emissions. We calculate a decade of emissions using trends in propellant consumption and re-entry mass to project separate growth rates in SMC (28% a$^{-1}$) and non-SMC (<20% a$^{-1}$) launches and re-entries. We implement this in the GEOS-Chem chemical transport model coupled to a radiative transfer model to characterize impacts of SMCs and all mission types on atmospheric composition and climate. By 2029, global chemical loss of stratospheric ozone from all mission types, dominated by chlorine from solid propellant, is small (0.03%) compared to regulated sources (2%). SMC missions predominantly use kerosene-fueled rockets that do not emit chlorine, so only account for 10% of all-mission ozone depletion. Kerosene is a large source of black carbon (BC) that, by 2029, induces instantaneous radiative forcing per mass unit BC emitted that is more than 500 times greater than BC forcing from Earth-bound sources. Unlike surface sources, BC emissions from rockets behave like proposed geoengineering strategies: a positive instantaneous top-of-the-atmosphere (TOA) forcing (6.47 mW m$^{-2}$) and a negative stratospherically adjusted forcing (-6.40 mW m$^{-2}$). SMCs account for more than half (56%) the instantaneous forcing and 42% the stratospherically adjusted forcing. Additional measurements from plume transects, satellite data and laboratory studies are crucial for constraining and validating our model findings.

Speaker: Dr Connor Barker (University College London)

35 Near-future rocket launches could slow ozone recovery

Rocket launches lofting payloads to orbit are unique anthropogenic injection points of emissions, emplacing gas and particulates while traveling up through the region of highest ozone concentration (15–35 km) at stratospheric altitudes. To understand if significant ozone losses could occur as the launch industry grows, we used a fully coupled aerosol-chemistry-climate model and examined two scenarios of industry aspirations, based on the linear extrapolation of well-documented year 2019 emissions. Our ‘ambitious’ scenario (2040 launches/year) yields a −0.29% depletion in annual-mean, near-global total column ozone in 2030. Antarctic springtime ozone decreases by 3.9%. Our ‘conservative’ scenario (884 launches/year) yields −0.17% annual, near-global depletion; current licensing rates suggest this scenario may be exceeded before 2030. Our analysis showed that ozone losses are mostly driven by the chlorine produced from solid rocket motor propellant, and black carbon which is emitted from most propellants. We additionally performed simulations of the potential geoengineering scenario through stratospheric injections of sulfur dioxide that elevates stratospheric sulfate aerosol levels. We found that this scenario can further amplify the negative effects of halogen-containing fuels through heterogeneous activation of reactive halogens on aerosol surfaces, which is mostly pronounced in the middle and high latitudes. The ozone layer is slowly healing from the effects of CFCs, yet global-mean ozone abundances are still 2% lower than measured prior to the onset of CFC-induced ozone depletion. Our results demonstrate that ongoing and frequent rocket launches could delay ozone recovery, which, however, depends on many factors including future climate scenarios, fuel types, launch locations, etc. Action is needed now to ensure that future growth of the launch industry and ozone protection are mutually sustainable.

Speaker: Dr Timofei Sukhodolov (Physical-Meteorological Observatory Davos / World Radiation Center (PMOD/WRC))

10:20 Break

36 CNES Atmospheric Roadmap

On June 18, during the Paris International Air and Space Show at Le Bourget, the CNES, DGE, and GIFAS presented the decarbonization roadmap for the French space industry. This roadmap, a world first, evaluates the carbon footprint of the French space industry at 1.8 million tons of CO₂ equivalent per year, but excluding high-atmosphere effects due to uncertainty. The industry proposes an ambitious scenario to reduce emissions by 49 % by 2040, aligned with the French National Low-Carbon Strategy (SNBC). Twelve action levers have been identified, including better understanding of high-atmosphere effects to reduce their impacts.
In-depth research is needed to better understand high-atmosphere phenomena and guide the development of less impactful materials and propellants. A CNES work plan has been launched to address atmospheric modeling, launch studies, and atmospheric re-entry studies. These research efforts aim to reduce the proportion of materials and propellants with high radiative impact or contributing to ozone depletion in order to respect the French decarbonization roadmap to reduce impacts. Priority actions include simulations, modeling, and characterization to better understand high-atmosphere phenomena, as well as the development of low-radiative impact materials or propellants and/or those that minimize ozone depletion and cooperation is a key to success.

Speaker: Mr Agwilh Collet (CNES)

37 Minimizing atmospheric re-entry impacts from a life cycle perspective

Satellite and upper-stage re-entries pose a dual challenge: fragments that survive to the surface create a casualty risk, while the ablation phenomenon injects metals, aerosols and reactive gases that can alter ozone and climate, and indirectly cause health effects.

MaiaSpace is a European space tech company designing, manufacturing, and operating more sustainable space transportation solutions. Its ambition is to have the lowest environmental impact of the industry on the Earth and space, while remaining competitive. Since day one, MaiaSpace has been evaluating the environmental impacts of its launch service through a Life Cycle Assessment (LCA) model.

Significant gaps remain in assessing the environmental impacts of space systems, particularly the high-atmospheric phases: launch and re-entry. To determine which strategy the Maia launcher should adopt for its upper stage and kick-stage re-entry to minimize environmental impact, we conducted a scientific review comparing two opposite approaches.

While Design-for-demise (D4D) minimises ground risks by maximising re-entry burn-up, design-for-non-demise (D4ND) aims to reduce high-altitude emissions. D4ND may require controlled descents, extra mass, or alternative materials, with consequences for other life cycle phases of the space object.

In this presentation, we review current evidence on casualty risk, atmospheric chemistry, and other feedback, showing that no unified metric yet exists, and set out research priorities for choosing the better end-of-life strategy .

Speaker: Antoinette Ott (MaiaSpace)

38 Including Life Cycle Analysis in Multidisciplinary Design and Optimization processes of launch vehicles

As the space sector experiences exponential growth, the environmental footprint of launch vehicles necessitates comprehensive examination. This presentation synthesizes advances in integrating environmental assessments into launch vehicle design, focusing on atmospheric emissions and life cycle analysis. This work focuses on the integration of predictive Life Cycle Assessments (LCAs) into design frameworks to enable systematic evaluations of sustainability alongside performance from preliminary design phases. For that purpose, a Multidisciplinary Design and Optimization approach is adopted, with new disciplines in charge of evaluating the Life Cycle Analysis of the launcher. This enables trade-off analyses considering both classical performance criteria (Gross-Lift-Off-Weight) as well as environmental footprint. Furthermore, quantification of uncertainties and sensitivity analysis can also be conducted in order to identify the impact of misknowledge on the LCA (e.g., database, emissions models) on the climate impact estimation. The preliminary results obtained with the approaches under development are illustrated on the design of a Two-Stage-To-Orbit launch vehicle highlighting performance-climate impact trade-offs. This work is part of an on-going effort involving ONERA, ISAE-Supaero and CNES.

Speaker: Alice De Oliveira (ISAE-Supaero)

39 Combining Re-entry Simulations and Material Chemistry Characterisation Methods for Closing the LCI Gap for the Demise of EEEE Part Materials

Current space safety rules require Low Earth Orbit (LEO) satellite operators to dispose their spacecraft through atmospheric re-entries. Effects of demising materials on the atmosphere, however, are not yet considered. According to the broadly recognised Life Cycle Assessment (LCA) method before assessing the impact of demising materials, a Life Cycle Inventory (LCI) is necessary. Unfortunately, still little is known about the elementary flows resulting from atmospheric demise especially with regards to electric, electronic, electro-mechanical, and electro-optical (EEEE) parts in spacecraft. This is a gap that research groups and agencies are trying to close with the help of computational models (DRAMA, CEA, Cantera, REAT) or with in-situ spectroscopy from within the spacecraft (e.g., DRACO mission). An alternative option is to conduct classical thermal simulation and plasma experiments originally designed to investigate the materials thermal resistance or ability to demise to simulate destructive re-entries. If coupled with state of the art in-situ and post-mortem material scientific characterisation methods, this approach can become a valuable addition to computational simulations and complex re-entry missions to understand and identify emissions from atmospheric re-entries. The herein proposed research has the goal to significantly contribute towards closing the defined LCI gap for atmospheric re-entries of the often overlooked internal EEEE parts of spacecraft and identify elementary flows and flow locations via combining material scientific characterisation with classical re-entry simulation. As depicted below, both in-situ and post mortem characterisation methods will be employed during and after experimental simulation of re-entry conditions. Plasma wind tunnel experiments as well as thermogravimetric analysis (TGA) and other plasma sources will be used to simulate selected re-entry conditions. During simulations, in-situ optical emission spectroscopy (OES), concurrent differential thermal analysis (DTA), and gas chromatograph (GC) will provide time-resolved data on behaviour, ablation, excitation, mass loss, chemical reactions, thermal decomposition and elemental ratios. Post-mortem analyses include optical microscopy, scanning electron microscopy combined with energy-dispersive X-ray spectroscopy (SEM-EDX), and X-ray diffractometry (XRD), which collectively characterise the morphology, chemistry, and phases of the residual materials. As shown below, assumptions and LCI results will be validated considering results from literature and state of the art re-entry simulation tools like REAT. For this research, TESAT’s Parts Agency and the Materials and Resource group of the Technical University of Darmstadt have collaborated to create a reproducible method to close the LCI gap, a crucial step towards holistic LCA of re-entry materials and the identification of sustainable re-entry materials.

Speaker: Dennis Michael Jöckel (TESAT Spacecom GmbH)

12:10 Lunch

13:40 Workshop Disussion