Voyager program: Mars orbiters
landers, rovers in the 1970s

1960: Jet Propulsion Lab (JPL) proposes Voyager as (JPL) proposes Voyager as Mariner follow-on
1963: Avco Avco performs performs Voyager design study
1964: NASA HQ formally approves Voyager
1966: NASA postpones Fiscal Year (FY) 1967 new start in exchange for Congressional assurance of aggressive start-up funding in FY 1968