Central to the plan was a Mars spacecraft in the spirit of Star Trek's Enterprise or Discovery from the film 2001: A Space Odyssey. A nuclear-powered Mars cruiser designed by Boeing measured almost 500 feet long and 100 feet wide. Two of these behemoths would travel to Mars in tandem, each toting a North American Rockwell-designed Mars lander. With a cost of $29 billion—$200 billion in today's dollars—the scheme marked the giddy high-water mark of Mars expedition grandiosity.
In September 1969, President Nixon's Space Task Group endorsed the NASA plan, but with reservations. NASA formed an agency-wide team to begin implementation. But Nixon ignored the task group's recommendations, opting instead to funnel NASA's budget toward building the space shuttle. In 1971 NASA ceased all manned Mars flight planning. According to some old hands, mere mention of Mars within NASA became verboten—the barely affordable shuttle was a target of frequent attacks, so one can only imagine how people would react to Mars.
After it fell afoul of Mueller's JAG efforts, the Voyager program reemerged as Viking, a probe that landed on Mars in 1976. Viking's life hunt yielded equivocal results, but other experiments hinted at a Mars with a complex Earth-like past and useful resources. The Viking results helped trigger a revival of Mars planning in the 1980s, an provided data for the central cost-saving technique in the current Mars plan—use of native resources to make rocket fuel. The name "Voyager" was re-applied to a program of outer planet exploration. Faget supervised design of the space shuttle, then retired near Houston. Paine left NASA in 1970. In 1985, the Reagan administration called upon him to chart NASA's future course a second time as head of the National Commission on Space, then, following the 1986 Challenger accident, quietly shelved his audacious vision of American settlements on the moon and Mars. He passed away in 1992.