2.2.2 spase://CNES/Observatory/CDPP-AMDA/Mariner10 Mariner 10 2019-05-05T12:34:56Z Mariner 10 was the seventh successful launch in the Mariner series, the first spacecraft to use the gravitational pull of one planet (Venus) to reach another (Mercury), and the first spacecraft mission to visit two planets. Mariner 10 was the first (and as of 2003 the only) spacecraft to visit Mercury. The spacecraft flew by Mercury three times in a retrograde heliocentric orbit and returned images and data on the planet. spase://CNES/Person/Stephen.E.Dwornik Scientist NSSDC's Master Catalog https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1973-085A Information about Mariner 10 spacecraft Mercury Heliosphere.Inner Venus