In 1961, the US Air Force made a tempting offer: Give us $7.5 billion, and we'll land a man on the moon by 1967. After that, they would establish a colony on the moon. Simple as that. The planned program was called LUNEX, and it wasn't the first proposal the Air Force made to send Americans into space.
In a history of LUNEX, Popular Science's Vintage Space blog writes that the Air Force first researched performing a lunar landing in 1958, and even had a plan that projected a 1965 landing. NASA's Project Mercury was given the green light instead. LUNEX, as Popular Science describes it, was a bold vision of space travel in keeping with America's views in the 1960s. It would push forward technological development, capture the imagination of the world, and, most importantly, prove our superiority over the Soviet Union.
"The program was presented as a preemptive strike against the Soviet Union," writes Pop Sci. "Air Force intelligence suspected that the Soviets, having launched the first satellite, first biological payload, and first manned orbital mission, were likely to continue developing technology with an eye towards securing more firsts. Particularly in unmanned reconnaissance missions. The LUNEX proposal sought to get men to the Moon before the roving laboratories and tankettes the Air Force expected the Soviet Union to launch before long.
"And of course, another strong motivating factor behind LUNEX was to increase the US’ military involvement in space. Knowing that the Soviets didn’t separate its military and civilian payloads, establishing an American military presence in space would leave the country poised to respond to future hostile satellites or missions."
Today it's hard to imagine what space exploration would look like if it had begun as a military, and not civilian, program back in the 1960s. Much of the speculative artwork of the decade even depicted space exploration with a military bent. The ship that would carry astronauts to the moon in the LUNEX plan also resembled the popular depictions of rockets in the day, complete with angular fins and a curved cylindrical body.
The plan called for a multi-stage rocket consisting of a lunar landing stage, a lunar launching stage for leaving the moon, and an Earth return vehicle. All told, it was a six-stage plan, "but in 1961 there were a lot of technologies that needed to be invented before this mission could fly," writes Pop Sci. "Notably unexisting was the launch vehicle called the Space Launch Sytem. Key decisions weren’t yet made, like what fuel it would use. The main question was over the first stage, whether it would be powered by the same liquid oxygen and liquid hydrogen mixture that would power the second and third stages or an equivalently powerful solid fuel. In either case, a rocket capable of delivering 6 million pounds of thrust at launch was needed to get LUNEX off the ground."
An audacious backup plan called for parts of the rocket to be assembled in orbit around the Earth. A rendevous with the LUNEX rocket would equip it with the parts necessary to continue its journey onwards to the moon.
Pop Sci writes that LUNEX had some other, seemingly unsurmountable issues to contend with when it was proposed in 1961. The Air Force would have to invent all the systems necessary to perform a space flight, from guidance and control to life support and thermal shielding. They also knew little about the lunar environment and what would be involved in landing and taking off. But NASA's Apollo program was in much the same place in 1961, and even had a similar orbital rendezvous backup.
If LUNEX had been chosen, Pop Sci points out, the space program would've been much closer to the shuttle program that was started in 1969. Space technology could've developed further and faster--and, quite possibly, been heavily militarized by the end of the Cold War.