Spacecraft Engines

There have been many different engines proposed over the years which were supposed to propel spacecraft fast enough to make space flight practical, because it really isn’t very practical yet. One of the problems is we are still using a method to travel through the solar system which is hundreds of years old and that is rocket power. We can thank the Chinese for it and if we didn’t have it we would never have reached the moon. The problem is it is not much good for human space travel as it is far too slow. We certainly wouldn’t want to spend years just to go to Mars and back and being in space that long presents all sorts of hazards, including radiation, meteor hits and even increased chance of mechanical breakdown. On top of all this riding a rocket is like sitting aboard a bomb. We have all seen how many of these things have blown up.

There have been all sorts of engines suggested for space travel and it is only naturalΒ someone would suggest a nuclear engine. One of the types suggested was a nuclear fusion ramjet. This would be a magnetic confinement nuclear fusion reactor. Until recently a working fusion reactor which puts out more energy than it uses was a dream until the Skunk Works at Lockheed announced they had invented one giving some credibility to this idea. The fusion ramjet would gather hydrogen from space as it travels through it. The ship would have to have a large scoop and the hydrogen would have to be dense enough to support the engine’s need. Some scientists have reviewed the operations of this type of engine and concluded it is not practical, because interstellar hydrogen is not likely to provide the power for an interstellar journey. In other words there is not enough hydrogen in space of the type and density the engine needs.

A fusion rocket is another story. The difference being it would carry its own fuel. It is estimated sending a crew to Mars using a standard rocket would take a round trip of four years. A research group funded by NASA at the University of Washington has said if a fusion rocket can be built it can accomplish a trip to Mars in about 30 days. A vast improvement over a chemical rocket. It is believed acceleration could reach 200,000 miles per hour using this type of engine. Far too slow for interstellar travel, but far faster than anything we are now using.

A plasma engine has been under development for decades by Franklin Chang Diaz founder of startup Ad Astra Rocket Company. The engine has been under development since 1973. The idea is to build a spaceship which uses one or more nuclear reactors to heat plasma which magnetic fields would eject. He believes the engine would allow the ship to reach 123,000 miles per hour. While he was pitching his engine in the 1980s he was called by NASA to become the first naturalized citizen to become an astronaut. Diaz is getting close to completion and states within four years his engine will be tested in space.

One source of propulsion in space has to remind us of how the early explorers came to North America, they did it by sailing there. There is something called the solar wind which is a stream of electrons and protons flowing outward from the sun. They travel at speeds as high as 900 km/s. Scientists believe we can build a sail which can be attached to a spacecraft. It would not be as fast as the other options, but it would not use any fuel. A trip to Mars would take a 9 ton spaceship 700 days with about 300 days to airbrake. Trips to the outer planets could benefit from swinging around the sun thus you could reach Jupiter in about two years. It seems the least practical method of travel, but on the plus side it might have the least chance of breaking down along the way.

NASA has been working on an EM engine for years. An EM engine converts electric power to thrust without the need for any fuel. It operates by bouncing microwaves around within a closed container. It seems to violate conventional physics and has never been tested in a vacuum, so with every test over the years skeptics said the only reason it was giving off power was the fact something else around it was really responsible. The last test however was aimed at proving this was not true and the power was coming from the engine and it did to the disgruntlement of those skeptics. The last experiment was designed with testing this in mind. The reason NASA is excited about this engine is the fact it should be able to reach a little over 9% of the speed of light. So what exactly does this mean to us? If we look at the nearest star we would be able to get there in 130 years when you consider it would take 38 years just to slow down and stop. I can’t get too excited over this, but I can get excited when I talk about using it for traveling around the solar system. We would finally be able to travel around the solar system in a reasonable amount of time.

We feel we need fast engines to be able to travel among the stars. Does this mean if there are aliens out there who are traveling around they have broken the speed of light in their travels? It might, or it might mean they live so long the time it would take slower engines to reach us doesn’t bother them. This doesn’t help us since our lifespan is a relatively short one in the scheme of things. We HAVE to be able to figure out how to travel these enormous distances and it could turn out the only answer is bending space. A sort of engine is being worked on now which would shorten the distance in front of a spaceship and lengthen the distance behind it, but the ship wouldn’t actually move, space would do the moving. We may never see an engine like this in our lifetime or if we chose to believe the death bed statement of Ben Rich, former head of Lockheed Skunk Works, we already have the ability to fly anywhere in the universe.