A119, the United States Project to Detonate a Nuclear Bomb on the Moon, in Which Carl Sagan Participated

On October 4, 1957, the USSR launched Sputnik I, the first artificial satellite in history, into orbit. That program would continue the following month with Sputnik II, which also carried the first living being to travel into space (the dog Laika).

The success put the Soviets ahead in the space race and dealt a major propaganda blow to the U.S. in the midst of the Cold War, so the Washington government deemed it necessary to deliver a dramatic counterblow, settling on something as unusual as detonating an atomic bomb on the Moon. This was the so-called Project A119.

Of course, it wasn’t an idea that came out of nowhere. In 1936, the ARF (Armor Research Foundation) was established, an institution that, as its name indicates, aimed to support weapons research at the Armour Institute of Technology.

The ARF is now the IITRI (IIT Research Institute), just as the other institution is now called the IIT (Illinois Institute of Technology), and both have shifted their activities toward scientific research and education, as a result of the new international context.

A119 Moon Nuclear Project — IIT Research Institute Headquarters. Credit: IITRI

But in the 1950s, they were in the midst of the atomic era, and their studies focused on nuclear devices and their effects: high-energy physics, consequences of such a war, survival conditions, etc.

In that context, spurred on by the USSR’s announcement of the imminent launch of another satellite, they began a new line of research requested by the USAF (U.S. Air Force): the possibility of detonating an atomic bomb on the Moon and what consequences it might have.

Moreover, it wouldn’t be an explosion in a crater but on the surface, because the flash had to be seen from Earth by all American citizens to boost morale after the Soviet success.

Indeed, on May 15, 1958, they launched Sputnik III into orbit. It was launched using a new intercontinental ballistic missile, the R-7 Semyorka, which had a range of 8,800 kilometers and a 3-megaton thermonuclear warhead whose first test launch as a weapon would take place the following year, in December 1959.

Therefore, and even though Sputnik III would ultimately fail in its mission, the ARF had a double reason to rush its lunar program, which was named Project A119. Even more so after, in that same month of May, intelligence services discovered that the USSR had planned to celebrate the anniversary of the October Revolution with a show of force, coinciding a nuclear detonation on the Moon with the eclipse scheduled for November 7, 1957, in what became known as Plan E-4 (Plan E-1 was simply to reach the Moon, while E-2 and E-3 envisioned sending probes to collect samples and take photographs). Obviously, they never carried it out, so, paradoxically, the U.S. may have adopted the idea.

In fact, it wasn’t entirely new, as there was a precedent set by Edward Teller, a Hungarian-born American physicist who was part of the Manhattan Project. A promoter of Operation Plowshare (use of atomic weapons in peaceful projects, mainly in engineering) and considered the father of the hydrogen bomb, he had also proposed a lunar detonation in February 1957 to analyze its effects.

He wasn’t the only notable scientist involved, as a ten-member team was formed under the leadership of Leonard Reiffel (physicist and engineer, collaborator of Enrico Fermi, and proponent of NASA’s Apollo Program), which also included Gerard Kuiper and a promising doctoral student of his.

Kuiper was a renowned Dutch-born, naturalized astronomer, discoverer of two satellites in the Solar System and several stars, as well as of the existence of carbon dioxide on Mars; he would later identify the sites where Apollo 11 would land. His surname may sound familiar because of the Kuiper Belt, the name given to a ring of celestial bodies orbiting the Sun whose existence he predicted in 1951.

But even more well-known is his doctoral student, whom he brought with him to the ARF for Project A119: Carl Sagan, an astronomer and astrophysicist who would become world-famous for his work in science communication, the most successful example of which was his educational television series Cosmos.

Sagan, specifically, was responsible for studying the spread of lunar dust that would result from the explosion—a significant cloud because, due to the Moon’s lower gravity, it might obscure the flash of the explosion and ruin one of the project’s attractions: the idea that anyone could see it from Earth.

In fact, the impact was supposed to occur on a full moon night so that sunlight would illuminate the nuclear mushroom cloud and enhance the visual effect. That meant ground zero had to be on the lunar terminator, the dividing line between the illuminated and dark areas of Earth’s satellite. It also required absolutely precise targeting, because a misfire could result in the missile orbiting the Moon and returning to Earth.

The missile in question was going to be small—nothing like the gigantic R-7 Semyorka. It was a W25, a type of uranium and plutonium warhead that entered service in 1957 and measured 68 centimeters in length by 44 in width, allowing it to be carried by fighter jets, often mounted on AIR-2 Genie air-to-air rockets.

Its yield was 1.7 kilotons, far less than the hydrogen bomb initially considered, which the USAF ultimately rejected due to its excessive weight, as it would have made reaching the Moon more difficult. The development of intercontinental ballistic missiles by the U.S. made the culmination of Project A119 feasible in 1959, but that very year it was canceled for several reasons.

As with the Soviet E-4 project, one reason was the fear that the public would react negatively rather than positively, even if nothing went wrong—let alone if it did, causing greater public frustration. There were also scientific concerns, due to the impossibility of knowing in advance what consequences the explosion might have on the Moon in the medium or long term, and what its future impact might be on a hypothetical human presence on the satellite.

One of the project’s goals was to analyze the effect of the detonation on the geological layer, something difficult to achieve through conventional methods; the Apollo Program would later do this using mortar explosives.

Both the U.S. and the USSR continued conducting ballistic missile tests with detonations in the stratosphere and, in that regard, forgot about the Moon. After the 1962 accident in the Soviet Project K, in which the explosion of a 300-kiloton warhead at an altitude of 292,000 meters melted thousands of kilometers of underground power and telephone cables, causing a fire at a power plant, the Partial Test Ban Treaty was approved. It was reaffirmed and expanded in 1967 with another treaty banning nuclear weapons in space, and again in 1996 with one prohibiting all nuclear testing in air, land, or sea.

That is why the proposal by Apollo Program scientist Gary Latham was rejected. He had suggested detonating a small atomic bomb on the Moon in 1969—after Armstrong had walked on it—to measure radiation.

However, Project A119 was not revealed until 1999, when writer Keay Davidson published his book Carl Sagan: A Life, which, as you can guess, is a biography of the scientist and came out four years after his death. During the research phase, Davidson discovered that Sagan had revealed the titles of two secret documents about the project in 1959 as part of his résumé, when he applied for a fellowship at the newly founded Miller Institute for Basic Research in Science, part of the University of California (Berkeley).

The journal Nature emphasized this detail and a controversy erupted, forcing Leonard Reiffel—who was still alive and lived to be a centenarian, not passing away until 2017—to disclose the existence of A119 and make the information public. And so it was, although little remained, as the Illinois Institute of Technology had destroyed most of it—two out of three volumes—in the 1980s. Times and attitudes toward nuclear issues had changed.

This article was first published on our Spanish Edition on October 21, 2019: A119, el proyecto de Estados Unidos para detonar una bomba nuclear en la Luna, en el que participó Carl Sagan