REACT: gREen spACE logistics tool

After the first project in which the project consortium developed a proof-of-concept software for simplified LCA of activities related to space launchers (GSL-ACT), REACT is the follow-up project funded by the ESA Future Launchers Preparatory Program (FLPP).

Satellites support humans in their daily life activities. These satellites are transported to specific orbits around the globe by launchers, or so-called «Space Transportation Vehicles». Some orbits already contain high amounts of space debris, which is a (collision) risk for all items in these orbits. High numbers of launches are planned for the near future. The Future Launchers Preparatory Program (FLPP) of the European Space Agency wants to learn more about the environmental impacts (both on Earth and in space) of various architectures of missions, Space Transportation Vehicles, or “Green Space Logistics”, namely:

Future launchers, including investigation of potential future propellants (e.g. Ariane 6)
Reusable launchers (e.g. SPACE-X launchers)
Transporting «Active Debris Removal Satellites» to orbits with high amounts of space debris to remove some of the debris
Optimisation of trajectories and architectures with regards to environmental impacts
In-space transportation (so-called end-to-end transportation)

Together with our partners, we continue to stabilize and expand the Assessment and Comparison software tool (ACT). ACT allows engineers at ESA or space companies to enter their design data – for instance on material use (type/mass), propellant type, thrust needed, thrust curve during launch, and target orbit. Improvements will include the coupling with a trajectory optimizing tool developed at ISAE Supaero, and a launcher emissions database by the University of Stuttgart. These entries and choices are translated into selected environmental impacts, e.g. climate change impacts or ozone layer depletion. These impact categories will as far as possible be adapted to include space specific emissions at various atmospheric layers and altitudes. For instance, the impacts of the emission of various combustion species from the propellants during the launch event into different layers of the atmosphere are not yet well-known, including their accumulative behavior and environmental effects. First models exist which could be coupled to the tool in the future. Further, the collision risk at various orbits leading to higher amounts of space debris needs to be quantified for each mission. A «Space Debris Index» has been developed during ACT-GSL, and will be refined within this project.

ACT visualizes environmental hotspots, results robustness, and uncertainties related to the specified system. The engineers can discover which Life Cycle Stages or building blocks contribute most to these impacts, and can e.g. evaluate the potential benefits of reusable launchers or various system designs. They can identify trade-offs between chosen environmental impact categories. Uncertainties may be important for technologies (e.g. launchers, propellants) with low Technology Readiness Level. Background data stem from an in-house ESA LCA database and the ecoinvent database. In order to be able to model future technologies only being deployed in several years, projections from Integrated Assessment Models are used by coupling them to LCA with premise.

FLPP further wants to prepare for digitalization, and wants a tool that allows coupling with other tools or codes. Due to the open-source nature of our python-based LEA software tool «Brightway2» for LCA, we can serve this need and support such activities.