[Stop reading now if you wish to avoid spoilers for Sea of Crises.]
Is it possible to fire a gun in the vacuum of space?
Yes. But, as Mason Gale experienced, you wouldn’t want to.
There’s no oxygen in space, but conventional ammunition doesn’t need it. A bullet is contained in a sealed casing, along with gunpowder and an explosive primer. When the hammer of the gun strikes the back end of the casing, it causes the powder, which already contains sufficient oxygen for the necessary reaction, to explode internally, propelling the bullet forward out of the gun’s barrel. In fact, a bullet traveling in space would, given the absence of external air pressure, actually travel faster and further than it would on Earth.
The big problem would be recoil. On Earth, recoil of a gun is, for the most part, offset by the weight and mass of the weapon and the shooter. On the moon, with only a fraction of the Earth’s gravity present and no air pressure, the force of the propellant blast generated by the firing of a gun would have nothing to offset it and would push the weapon backwards at a dangerous clip.
Though American astronauts did not carry guns into space, the Soviet cosmonauts did - not for the purpose of shooting other people, but rather for survival following return to Earth. Unlike U.S. space vessels, which splashed down in the ocean, Soviet craft typically came down on land within the U.S.S.R., leaving cosmonauts sometimes waiting for long periods in remote locations on the desolate Soviet steppe, where they were vulnerable to attack by wolves and other predators. To this day, in fact, there is purportedly a Russian firearm aboard the International Space Station.
Did the Soviets actually have a military space program?
Yes. Under the code name “Almaz” (which means “diamond” in Russian), the Soviet Union launched a series of secret military reconnaissance space stations in the early 1970s under cover of the civilian Salyut program. There were actually three Almaz stations: Salyut 2, Salyut 3 and Salyut 5.
Salyut 3 was, as Mason Gale tells Bob Cartwright, equipped with a 23mm rapid-fire cannon mounted on its forward belly, and it was successfully tested by the Soviets on a target satellite. It wasn’t a particularly functional weapon, however. To bring it to bear on a target, the entire vessel had to be rotated. And, of course, there was the whole recoil issue with which to deal.
Now, there is no evidence, to my knowledge, of any intent on the part of the Soviets to establish a military presence on the moon. But, then again, who knows...
Why would anyone, including the Soviets, want to have a permanent (and exclusive) presence on the moon?
This one I’ll leave primarily to the imagination of my reader. It’s more speculative than factual. That said, a couple of thoughts:
1. At some point, humanity is likely once more to engage in manned exploration of space. And the moon is a logical jumping off point. It provides a steady platform for staging missions intended to reach further into our solar system - and perhaps the galaxy beyond. It certainly seems logical that the nation controlling that platform would have a leg up on everyone else. Further, keep in mind that, in 1976, when the novel’s fictional events transpire in the Sea of Crises, the U.S. and the Soviet Union were locked in a deadly race for predominance over pretty much everything. Consequently, it’s not much of a logical leap to think that the powers-that-be in Moscow might have considered claiming dominance over the moon as their way of one-upping the United States, particularly after the Soviets’ humbling loss to the Americans in the race to be the first to land on the moon.
2. Over the years, there has been a fair amount of speculation regarding whether and to what extent there might be things present on the moon that could be of significant value back on Earth.
Here on Earth, there are a series of minerals known as “rare earth elements” that are used in everything from TV displays to magnets in hybrid electric motors. For those familiar with the periodic table, they include light elements ranging from lanthanum to gadolinium and heavy elements ranging from terbium to lutetium. The availability of these rare elements is generally considered to be a matter not only of economic prosperity, but of national security. Based on samples returned by the Apollo astronauts, scientists believe that there are local concentrations of these rare earth elements on the moon. Now, whether those elements can be isolated and profitably mined is another matter altogether. But, as their values and scarcity rise, the prospect of looking to the moon for them becomes that much more appealing.
Perhaps more importantly, there is an element on the moon that is not present in abundant natural form on Earth. Known as helium-3, or HE-3, it’s an isotope of helium containing two protons and one neutron in its nucleus. (A standard helium nucleus has two protons and two neutrons). It’s created on the moon when charged particles from the sun impact the lunar surface. On Earth, those same solar particles are either deflected by Earth’s magnetic field or absorbed by the atmosphere. HE-3 is of interest to fusion researchers and may be a possible fuel for future fusion power plants, providing an enormous supply of safe power. It can be and is manufactured on Earth in small quantities, but there’s no current practical method for supplying the amount that would be needed for HE-3 nuclear fusion to be a viable source of energy.