The Soviet Space Cannon
High above the bright blue Earth a metallic craft listlessly makes its way around the planet, hanging in the atmosphere like an ornament for all to observe. The unassuming craft lets out a groan before thrusters sputter to life, in the same moment several bright flashes can be seen coming from the opposite end of the object. Another hunk of metal in the distance is immediately obliterated to hundreds of tiny pieces!
Salyut 7 space station. Courtesy of Ars Technica.
Project Almaz
During the Cold War both the United States and the Soviet Union were continually developing technology to spy and gain intelligence on one another. Satellites were launched by both sides for observation and reconnaissance purposes, but the Soviets wanted to take the idea a step further with the use of a manned space station that could spy on its enemies and gather information. The idea for a habitable military space station was conceived by Vladimir Chelomey in 1964 and gained approval for production in 1967. It was codenamed project “Almaz”, meaning diamond in Russian, and was an ambitious project, even by today’s standards.
Vladimir Chelomey. Courtesy of Russian Space Web.
The station was designed as an 11 meter long cylinder that weighed upwards of 20 tons and was to be outfitted with high tech optical sensors, radar, and a large telescope. It was powered by solar panels and had two engines towards the back of it that would be used for course correction once in orbit. The station would be manned by two or three cosmonauts whose primary goal was to take photographs of Earth and obtain intelligence on American assets.
An artist depiction of the Almaz. Courtesy of Sven’s Space Place.
Another aspect of the station that the Soviets toyed with was that of self defense. Many USSR officials were terrified that the United States would attempt to inspect or even capture one of their satellites and steal their closely guarded secrets. This was a very real threat as America was developing ways to shoot down satellites and even methods of capturing them to bring back to Earth, though these projects were more geared towards the reclamation of old satellites of their own that they had lost contact with instead of as an offensive maneuver. Still the need for some sort of self defense mechanism for military spacecraft was ever present and project Almaz would be the first to breach the idea.
The different stages of the Almaz station. Courtesy of Astronautix.
Space Cannon
Development of the gun used on the Almaz station was assigned to the Moscow based KB Tochmash design bureau and led by Aleksandr Nudelman. The engineers of this bureau had really proven themselves during World War Two with breakthroughs in aviation weaponry and were perfectly suited for the task. Nudelman and his team began taking an interest in the R-23M Kartech, a powerful 23 millimeter autocannon designed by Aron Rikhter for the Tupolev Tu-22 Blinder supersonic bomber. They took the basic design and scaled it down to 14.5 millimeters, likely because spacecrafts are somewhat delicate and do not require such a large shell to bring them down and to lessen the recoil which is a big problem in space due to the lack of gravity. (Note that most weapons experts do not consider anything under 20 millimeters a cannon but since this was designed for anti material purposes it is generally still considered one.) The cannon weighed 37 pounds and was able to fire a 200 gram (7 ounce) projectile at 690 meters per second (2,264 feet per second) and at a rate of between 950 to 5,000 rounds per minute. It is not known if the cannon had select fire capabilities, but the original did not and had a rate of fire of between 1,800-2,000 rounds per minute which is likely a more accurate estimate than the much wider range shown above.
One of the very few images of the cannon. Courtesy of Ars Technica.
The gun performed well in tests and had an effective range of up to two miles, which likely would have been quite handy in the vastness of space. Those that worked on the project recalled that during one test they had pierced a metal gas canister from a mile away during testing. When the cannon was mounted to the station it was so that the thrusters could be used to counteract its recoil. In space Newton’s laws are taken to the extreme so if there is no force to counteract that of the gun when it is fired then the station would move in the direction of the recoil and be flung wildly off course. The pilot did have a sight that could be used to aim the cannon, but the entire station had to be moved and lined up with the target in order to do so because the gun was in a fixed position.
A computer generated image of the cannon built for the Almaz project. Courtesy of Anatoly Zak.
Setbacks
While the gun itself was finished on schedule the rest of the Almaz project was lagging far behind. It took much longer to produce the high tech sensors and other spy equipment than initially thought and some Soviet officials were beginning to have doubts; in addition the military only showed mild interest in the project since they were successfully using unmanned satellites for their needs. However NASA’s skylab was set to launch in 1973 and the USSR did not want to lose the race to put the first manned space station into orbit.
The R-23M Kartech mounted below the engines of a supersonic bomber. Courtesy of Wikiwand.
In order to beat the Americans they decided to scale down the Almaz project from a military to a civilian one. While Almaz was being built there was a competing civilian space project called Soyuz. Soyuz was completed on time but the station turned out to be too heavy for the rocket boosters built for it, so to remedy both problems they took what they had already built for Almaz and integrated it with parts from Soyuz. The new station was launched in 1971 under the name Salyut, beating the Americans in this leg of the space race. This win helped the Soviet space program score some political points and the Kremlin allowed the Almaz project to proceed.
A version of the Soyuz rocket, this was taken in 2006. Courtesy of NASA.
The project was changed somewhat after this setback. At its heart it was still a military project but it would remain under the guise of a civilian one in order for them to deny that they had any military involvement in space. Seven satellites were launched under the Salyut name, three of which being Almaz military spy stations. US intelligence and independent observers easily figured out which were which, but the USSR would keep the military project secret until the end of the Cold War.
Firing
On June 25, 1974 the Salyut-3, the only known manned military station ever flown, was launched. (Salyut-2, which was supposed to be a military satellite, had launched successfully but was never manned due to the capsule depressurizing before a crew could man it.) Officially it was for scientific research on how lack of gravity affected the human body, but it was actually a spy station that had 14 cameras and special sensors that were to be used to track objects of interest on Earth. Tagging along with the spy equipment was the space cannon.
A drawing of the Salyut 3. Courtesy of Gunter’s Space Page.
Scientists were unsure of how firing the cannon would affect the station itself, especially with no gravity, so the test was to happen just hours before it was deorbited and long after the two man crew had returned to the planet. On January 24, 1975 the station's jet thrusters roared to life while the cannon was fired simultaneously. There are differing accounts of what happened but the cannon fired between 1 to 3 bursts with around 20 shells in all, the shells eventually burning up in the atmosphere. Cosmonauts have said that a test satellite was hit and destroyed by the cannon, though this has never been confirmed by the Russian government and many of the documents are still classified. However the next Almaz station that was to be launched was equipped with a pair of interceptor missiles rather than the cannon, whether this was just for test purposes or due to poor performance of the cannon is unknown. It is also unknown how effective the rockets were as the upgraded Almaz station was grounded before its scheduled launch in 1978, never making it to space.
Personal Thoughts
This has interested me ever since I learned about it and I do wish there was more information available. I really like space exploration and learning about the crafts and technology used, even though I don’t always understand everything about it. The Soviet space program is particularly interesting because they did do a lot of crazy things and there is still to this day a lot of information that is classified. I kind of wondered why they didn’t put the cannon on a swivel so they wouldn’t have to move the whole station but I think it’s because it wasn’t manned when they fired it and it was done remotely. There is probably another reason related to physics in space.
Sources
Cover photo is Public Domain
https://www.popularmechanics.com/military/weapons/a18187/here-is-the-soviet-unions-secret-space-cannon/
http://www.astronautix.com/a/almaz.html
http://www.svengrahn.pp.se/histind/Almprog/almprog.htm
https://www.britannica.com/technology/Salyu
