VacuSen sensor

German company ESCUBE’s VacuSen sensor for vacuum and plasma
applications is a spin-off from a ceramic gas sensor developed by ESA
and the University of Stuttgart to measure the atomic-oxygen levels
around reentry spacecraft under extreme test conditions. Today the
sensor is mounted outside the International Space Station, in ESA’s
Flux-(Phi)-Probe-Experiments (FIPEX) and used in a German glass
factory.