2.4.1 spase://CNES/Instrument/CDPP-AMDA/MESSENGER/ephemeris Ephemeris 2017-01-01T21:10:13Z MESSENGER Spacecraft Ephemeris Virtual Instrument spase://CNES/Person/CDPP-AMDA/NAIF PrincipalInvestigator Platform Spacecraft position spase://CNES/Observatory/CDPP-AMDA/MESSENGER