Lunex Project

Before Apollo, the US Air Force had its own plan for a crewed Moon landing: the Lunex Project, initiated in 1958. By 1961, the final plan envisioned a 21-person underground Air Force base on the Moon, operational by 1968, with a total price tag of $7.5 billion. The goal was to beat the Soviet Union and prove America’s technological leadership.

The key difference between Lunex and the later Apollo missions was the rendezvous method. Lunex used a direct ascent approach: the entire spacecraft—a combined landing module and lifting-body return module—would land on the Moon as one unit, then launch the whole vehicle back to Earth. In contrast, Apollo’s final design used lunar orbit rendezvous, where a separate ascent module left the command and service modules orbiting the Moon with one astronaut aboard. (Apollo’s original plan had also called for direct ascent, similar to Lunex.)

The Lunex lander was designed for a crew of three. It measured 16.16 meters (53.01 feet) long, with a maximum diameter and span of 7.62 meters (24.99 feet), and a mass of 61,000 kilograms (134,000 pounds). The agency behind it was the USAF.

Base locations were to be chosen by automated probes; one studied site was Kepler crater. The first lunar landing and return was planned for 1967, timed to beat the Soviets. The Air Force believed only a lunar landing would carry enough historical weight to win the technology race.

Direct ascent was seen as promising because it avoided the complexities of lunar orbit rendezvous—no need to develop space rendezvous techniques. The downside was that the Lunex spacecraft had to carry extra fuel to land the entire vehicle on the Moon and return it to orbit, making it much heavier than Apollo and requiring a larger rocket.

Major challenges included: re-entry at 11,000 m/s (37,000 ft/s) within a two-degree flight path to avoid overheating or skipping out of the atmosphere (which would expose the crew to Van Allen belt radiation); developing a lunar landing stage that could make a precision, tail-first rocket landing (never tested before); and building a lunar launch stage with no backup, requiring extreme reliability and automated checkout on the Moon’s surface to put the crew on the correct return orbit.