2.2.2 spase://SMWG/Instrument/VenusExpress/ASPERA4 Venus Express ASPERA-4 2012-06-13T00:00:00Z ASPERA-4 (Analysis of Space Plasmas and Energetic Atoms, version 4) consists of an ensemble of instruments to study the interaction between the solar wind and the Martian atmosphere and to characterize the plasma and neutral gas environment. The instruments consist of a Neutral Particle Imager (NPI), a Neutral Particle Detector (NPD), an Electron Spectrometer (ELS), and an ion Mass Analyzer (IMA). NPI provides good ENA arrival direction resolution but little energy or mass resolution, while NPD provides energy and mass resolution but little directional resolution. spase://SMWG/Person/Stas.Barabash PrincipalInvestigator PSA ASPERA web page ftp://psa.esac.esa.int/pub/mirror/VENUS-EXPRESS/ASPERA4/VEX-V-SW-ASPERA-2-ELS-V1.0/CATALOG/INST.CAT NeutralAtomImager RetardingPotentialAnalyser ASPERA4 spase://SMWG/Observatory/VenusExpress