PAseos Simulates the Environment for Operating multiple Spacecraft

The next generation of spacecraft is anticipated to enable various new applications involving onboard processing, machine learning and decentralised operational scenarios. Even though many of these have been previously proposed and evaluated, the operational constraints of real mission scenarios are often either not considered or only rudimentary. Here, we present an open-source Python module called PASEOS that is capable of modelling operational scenarios involving one or multiple spacecraft. It considers several physical phenomena including thermal, power, bandwidth and communications constraints as well as the impact of radiation on spacecraft. PASEOS can be run both as a high-performance-oriented numerical simulation and/or in a real-time mode directly on edge hardware. We demonstrate these capabilities in three scenarios, one in real-time simulation on a Unibap iX-10 100 satellite processor, another in a simulation modelling an entire constellation performing tasks over several hours and one training a machine learning model in a decentralised setting. While we demonstrate tasks in Earth orbit, PASEOS is conceptually designed to allow deep space scenarios too. Our results show that PASEOS can model the described scenarios efficiently and thus provide insight into operational considerations. We show this in terms of runtime and overhead as well as by investigating the modelled temperature, battery status and communication windows of a constellation. By running PASEOS on an actual satellite processor, we showcase how PASEOS can be directly included in hardware demonstrators for future missions. Overall, we provide the first solution to holistically model the physical constraints spacecraft encounter in Earth orbit and beyond. The PASEOS module is available open-source online together with an extensive documentation to enable researchers to quickly incorporate it in their studies.