EUROPEAN TECHNOLOGY EXPOSURE FACILITY- PLASMA ELECTRON GUN PAYLOAD (EUTEF-
PLEGPAY)
Research Area: Fundamental Physics
Expedition(s): 16- 20
Principal Investigator(s): ● Giovanni Noci, Thales Alenia Space, Florence, Italy
RESEARCH OBJECTIVES
The European Technology Exposure Facility-
Plasma Electron Gun Payload (EuTEF-
PLEGPAY) experiment is electrostatic charging
and discharging of gases in low-Earth orbit on
large space structures, identifying a
potentially fatal problem for spacecraft
electronics. In order to perform controlled
experiments, PLEGPAY provides a pressurized
gas tank with dose controller and timer, such
that the inert gas xenon can be released into
the chamber where it becomes ionized by
electrons emitted by an insert for ignition.
RESULTS
The first runs of the first PLEGPAY experiment
demonstrated the capability of the plasma
contactor device to control the potential of a
very large spacecraft such as the International
Space Station (ISS) through the biasing of the
plasma contactor. Furthermore, experiment 2
demonstrated the capability to lock the ISS
potential around zero by small current
emission, and the PLEGPAY Langmuir Probe
measurements were found to match the
independent floating potential measurements made by the NASA Floating Potential
Measurement Unit.
This investigation is complete; however additional results are pending publication.
Plasma Electron Gun Payload instrument located on the
outside of the International Space Station. ESA image.