Description
The Objective: The objective of the activity is to design, manufacture a testbed to determine materials behaviour of atomic oxygen fluence exposure representative in Very Low Earth Orbit (VLEO) environment. With the help of the testbed, in a second step, an aerodynamic and oxygen fluence resistant coating will be developed and evaluated as needed for protection of exposed parts of the spacecraft to the VLEO environment.Targeted Improvements: Enabling for the material selection and for the design of spacecrafts in VLEO thanks to a testbed with atomic oxygen fluxes of at least 1e18 at/cm2/s not existing today in ESA member states.Description: Very Low Earth Orbit (VLEO) for telecommunication spacecraft will bring significant advantages, lowering the latency of signals and increasing throughput. However, VLEO environment is harsh and operating a spacecraft in this altitude range is very challenging. Spacecraft will undergo significant drag forces and materials will be, among other constraints, submitted especially to very high atomic oxygen fluences. This will lead to their erosion and/or chemical modification, changing their functional properties. It is mandatory to identify which materials will be able to survive and maintain sufficient performances within this specific environment to ensure the mission operation until end-of life. However, conventional atomic oxygen facilities based on pulsed laser beam have flux limitations and it is thus not possible to cover the expected fluences for a typical mission of several years in very low earth orbit.The activity will develop a new testing methodology to adequately assess the potential effects of atomic oxygen on materials and the associated impact on the functional properties. An aerodynamic coating will be developed diminishing the satellite drag by lowering theenergy transfer and scattering angle randomisation during gas-surface collisions. Compatibility with VLEO environment shall be tested and aerodynamic property improvements shall be verified through dedicated experimental campaigns.Test and characterisation campaigns shall be performed to determine the evolution of the material properties. The link between material ageing, functional properties degradation and system performances shall allow the definition of a spacecraft design robust to very low earth orbit environment.