Voyager program (Mars)

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The Voyager program was a planned series of unmanned NASA probes to Mars. The missions were planned between 1966 and 1968 and scheduled for launch in 1974–75.The probes were conceived as precursors for a manned Mars landing in the 1980s.

Originally NASA had proposed a direct lander using a variant of the Apollo Command Module launched on a Saturn IB with a Centaur upper stage. With the discovery by Mariner 4 (1965) and later the Mariner 6 and Mariner 7 in 1969 that Mars had only a tenuous atmosphere the mission was changed to have an orbiter and lander. This required the use of a Saturn V to launch two probes on a single booster. The orbiter would have been a modified Mariner probe identical to that employed for Mariner 8 and Mariner 9, while the landers would have been Surveyor moon probes modified with the use of aeroshells and a combination parachute/retrorocket landing systems.

Funding for the program was cut in 1968 and the mission cancelled in 1971, mainly on the grounds that unlike the Mariner program, which launched twin spacecraft on separate rockets, the failure of a single Saturn V booster at launch, as what had happen on Mariner 1 and Mariner 8, or a launch shroud separation failure, as what had happened on Mariner 3 (and coincidentially on the Gemini 9A docking target) would have doomed the spacecraft.

Much of the planning and development effort of the Voyager program formed the basis of the cheaper and simpler, yet still very ambitious, Viking program, which were launched, like its Mariner predecessors, atop separate Titan III-E/Centaur rockets.

The same name was later used by the Voyager 1 and 2 outer planet probes; see Voyager program.