Speaker
Description
- measuring incoming auroral low energies fluxes and spacecraft absolute voltage -
Electrostatic discharges (ESD) are a major risk of failures in orbit. From temporary outage to power loss with secondary arcing, the panel of possible degradation is very wide. The tribute already paid by the agencies, insurance or operator is certainly very high and expressed in millions euros.
Coming from the sun, particles hit all the spacecraft on every orbit, building up very negative absolute potential. Then difference in materials, temperature, lightening allows to create voltage gradient at the origin of ESD.
The AMBER experiment, onboard the ocean topography mapper Jason-3, aimed to measure the spacecraft absolute potential and auroral particle precipitation, consists of 2 top-hat analyzers for electrons and ions in the energy range 10 eV-28 keV. Each spectrometer has a 180° zenith pointing field of view divided in 4 anodes.
The Jason-3 satellite launched 2016, January 17th is orbiting nearly circularly at an altitude of 1336 km with an inclination of 66.04°. Given its low inclination, the satellite probes at times the south part of the auroral oval nearly tangentially when going out from the outer radiation belt.
When the spacecraft is in the dark or the Shadow, absolute potential above one kilovolt are often registered and when the absolute voltage is near zero, Amber provide nice records for the scientist, positive fluxes injection were already discovered.
Internal charging and adaptation to MEO orbit are the very last improvement.
This paper will present Amber, its capability, some charging results and the worst case spectrum associated and its evolution and versatility to launch it on every kind of spacecraft
Amber data are now freely available on CLWEB at IRAP: http://clweb.irap.omp.eu/
Feel free to ask for an account.
NB: From electronic and mechanical design, testing, …, to file treatment, a space project is a long way involving here for Amber, many people from CNES, IRAP, EREMS, COMAT and ONERA. It is impossible to name all of them, but they are warmly thanked.
