TheMariner program was a program ofspacecraft launched byNASA between 1963 and 1973. The spacecraft studied theplanetsMars,Venus andMercury. There were 10 spacecraft in the Mariner programme, named Mariners 1-10. Seven were successful but three were lost. The program included spacecraft doing things that spacecraft had never done before. These things included the first planetary fly-by, the firstpictures from another planet, the first planetaryorbiter, and the firstgravity assist maneuver. Other spacecraft in the Mariner program were planned but they were changed into other spacecraft with different names. For example, Mariner 11 and Mariner 12 were planned but changed intoVoyager 1 andVoyager 2.
