Speaker
Description
Radiation, thermal extremes, low pressure, and Atomic Oxygen (ATOX) are inevitable factors limiting lifetime and functionality of spacecraft in Earth orbits. Particularly ATOX is considered as
one of the most serious hazards to spacecraft materials at altitudes of 200 to 700 km. Due to its
reactivity and relative orbital speed of about 8 km/s, it leads to spacecraft material erosion, degradation, performance issues, and potential system failure. Ground testing is crucial for qualifying
space hardware to reduce operational risks. ATOX test facilities are becoming more important due
to increased popularity of Very Low Earth Orbits (VLEO), especially for defense payloads. These
facilities try to mimic projected atmospheric conditions like particle flux, velocity distribution, elemental composition, ion fraction, and ambient pressure. However, it’s experimentally challenging
and complex to measure such parameters reliably. Most facilities only report very limited data, if at
all. At FOTEC, we developed a test facility prototype where also larger samples and (sub)systems,
potentially up to live thrusters and smaller satellites, could be tested. This facility is based on an
oxygen ion beam source with controllable ion velocity distribution and flux. The beam is then neutralized by an electron source creating the (V)LEO ATOX environment in the vacuum chamber. This
ion source is already functional. It can be mounted in any of our large vacuum chambers (up to 3 m
length and 2.5 m diameter). Our current work focuses on characterizing and improving our physical
under-standing of the device. By applying diagnostics in form of a Retarding Potential Analyzer, a
high precision digital Faraday cup, an internal plasma electrode, a residual gas analyzer, and Kapton witness samples, we compare test conditions with the targeted atmospheric conditions. Once
requirements are reached, a coupling test with our FEEP thruster will be performed. Afterwards,
our goal is to provide the new facility for environmental testing of space hardware for internal use
and as a service for third parties within our “One Stop Shop for Space Testing”strategy.