Did you ever notice the similarities between a submarine and a spaceship? Both depend on being airtight to keep their occupants alive. Any vehicle which is in a hostile environment and has to keep people alive inside may be considered the equivalent in purpose. Since we are so good at building submarines, how come we don’t build a sturdy submarine type spaceship? We could build it in space and if built with the same standards as a military submarine it would be much better protected than any space vehicle we have ever sent into space. The key is not building it on earth, because we would have to figure out how to launch it into space which would be an impossible task right now due to the weight. One has to wonder how hard it would be to convert one of our submarines to a spaceship. Everything needed for a trip is already built into the submarine except the air supply which in many submarines is dependent on extracting oxygen from the water around it. The nuclear reactor already in many submarines can be used to power the submarine in space if modified to create a nuclear rocket. Since both submarines and spaceships are sealed containers, a space submarine seems to be a good choice for space travel. It could launch a smaller vehicle for landing on a planet or object. We are talking of course about a vehicle to transport people.

Our submarine wouldn’t need to use its ballast tanks in a traditional way since they are filled with water to dive and emptied to ascend. The tanks might be able to serve a second use and that is hold fresh water or even an oxygen reserve. We could remove the tanks or even turn them in to cargo areas. The thicker hull of our submarine would cut down on the dangers of radiation but not enough. We could add layers of lead between the outer and inner hulls for radiation protection and might even consider removing the outer hull since it would not be needed. The outer hull of a submarine is used to make the submarines trip through the water more efficient. It would not be needed for our spaceship submarine. The inside hull is the pressure hull and the truly strong one. Some Soviet submarines were built of titanium and so strong they could dive to over 3,200 feet.

When a submarine is built, it is constructed to resist the outside pressure. A spaceship would have no outside pressure if it just travels through space and doesn’t enter any planet’s atmosphere, so its main job is keeping the pressure inside. I don’t think there would be a problem since the inside pressure is far less than what would have been exerted on the submarine in the ocean. The pressure on earth is 14.7 pounds per square inch. A modern US submarine can reach about 350 meters in depth. At 300 meters the water pressure is 433.51 pounds per square in. I hardly think the 14.7 pounds of internal pressure which the submarine would have in space would be a problem for the structure of the submarine. When building something in space weight is not such a grave problem as it is when building something on earth to be sent into space, because this object would have to be lifted from the planet into orbit. It is a problem in that we must be able to get the mass moving and the heavier it is, the harder to get it going and to stop.

Titan is one of the moons of the planet Saturn. It is believed to be covered with liquid oceans. It is the largest of Saturn’s moons and has a dense atmosphere. Titan has a diameter 50% larger than our moon and it is believed to be 80% denser. Why am I suddenly bringing this up? It seems to fit into a use for our submarine spaceship. What if we could fly our submarine to this moon and then use it to dive into one of Titan’s oceans? The oceans are said to be made up of hydrocarbons not water, but could there be life forms living in the hydrocarbon which we don’t suspect. It would be very handy to have a spaceship submarine in this case, even a robotic one. For years engineers on earth have dreamed about creating a plane which could double as a submarine, diving into the ocean to escape detection. Unless there is some secret project I don’t know about, we have never succeeded in this endeavor. The planes were too heavy to be useful in the sky and not strong enough to allow them to dive very deep. Our spaceship submarine couldn’t actually dive into Titan’s oceans, because it probably would be too heavy to get off the planet and also would probably have to crash into the ocean, again because it would be so heavy it would be impossible to slow down.

Don’t give up hope yet. So far we have been talking about traditional types of metal from the strongest steel to Titanium, but guess what? There is a new kid on the block, it is a new magnesium alloy and it is being billed as the world’s lightest metal and also the world’s strongest. So far the metal has found uses in computers, cameras and other devices. This has nothing to do with what I am talking about, but I would like to mention the fact scientists have found magnesium limits infections in humans. Could a super strong and light submarine be built out of this new type of magnesium? I don’t know the answer, but if it could it would certainly go a long way to making submarines much lighter. When I was in the military magnesium was used for trailers which contained radar equipment and operators. They had to be extremely careful not to smoke or have lighted flames inside, because the trailers were purposely made of magnesium so they could be set on fire easily and the equipment destroyed so an enemy would not be able to use it. I would assume the new magnesium is less likely to burn.

Is it a big leap from submarine to spaceship? It would seem to me that half the work to create a spaceship from a submarine would not be necessary, but I am not an engineer and if anyone wants to comment on this, they can send me an email and I would add their reply to the end of the article. By the way NASA is considering sending a submarine to Titan, a small submarine, but it will not be sent as a spaceship. The scientific community is interested in Titan, because they want to know if the conditions there are the same as our primitive earth contained. A secondary purpose of this submarine is to look for extraterrestrial life. Some scientists believe a hydrocarbon soup can act as a replacement for water in begetting life.

While this has only been an exercise in imagination, perhaps we will see something similar in the future. Sometimes the newest inventions are based on some of the oldest, there are examples of this throughout history and maybe we will find that all our research in submarines has led to some of the best spaceships.