Nuclear Rockets
I have to admit it, I’m starting to get puzzled. Several months ago Lockheed announced they had developed a fusion reactor which could be scaled down small enough to put on a plane. I haven’t heard anything about it since and now we’re starting to hear about the new German fusion reactor which is said to have created hydrogen plasma for the first time. The German reactor doesn’t seem to be one which could ever be scaled down to what Lockheed claims they can do with their reactor. One of the first questions I had when I heard about Lockheed making this announcement was why would they do it? The announcement was coming from the Lockheed Skunk Works. This is the ultra-secret division, which is responsible for much of the stuff we never hear about and also a few of the things we do such as stealth aircraft.
Fusion reactors have been the dream of scientists for 100 years. Many scientists used to think they would power everything on earth and there are still some scientists who feel this way. While we all know nuclear reactors are dangerous, fusion reactors are a lot less dangerous and don’t produce the enormous amounts of radioactive waste a fission reactor does. Things have changed in some ways since we first thought about these things. I think many of the scientists today realize we don’t need fission nuclear reactors to power the earth since there is plenty of renewable energy out there which is even safer. Where fission reactors could come in handy would be to power spacecraft or if we can make them small enough as Lockheed claims, to act as a backup system in a disaster area. You would get far more power out of a fusion reaction then you would get from a generator. One small fusion reactor could power an entire neighborhood in the event of an emergency.
A fusion rocket would make space travel much faster for us in our solar system. While we still don’t seem to have anything which would be ideal for traveling between solar systems, the fusion rocket which certainly lift some of the restraints and travel time for traveling around in our own solar system. It takes a long time to travel around the solar system and if you’d like to know how grueling it really is let me remind you about how long it took NASA’s Cassini spacecraft to reach Saturn. It blasted off in October 1997 and entered Saturn’s orbit in July 2004. This certainly would be totally unacceptable if humans wanted to travel to Saturn and in the future such incredibly long time periods will certainly be laughed at as people travel through the solar system in under one hour or faster, but right now even though we can’t reach these incredible speeds we still need to make improvements in travel time. When scientists talk about sending people to Mars by the mid-2030s the are contemplating a trip that would take about six months to get there and six months to get back. Right now the time to get to another planet is determined by the launch speed.
If we switch from a chemical rocket to a nuclear fusion rocket it is estimated we could reach Mars in 30 days. It would still be a tiresome journey but it would only last about one sixth of the time a chemical rocket would take. One of the interesting things Lockheed had stated was that they would have their fusion reactor ready for use in five years. This means we would have a fusion reactor small enough to put into a rocket and it would be ready before the 2030 deadline set to launch astronauts towards the red planet. There are other problems however that even a fusion rocket cannot solve and one of the big ones is protecting the crew from radiation. Scientists have been working feverishly on ways to create a plasma which would surround the rocket and act as a shield protecting the rocket from cosmic rays and maybe even the occasional blast from the sun. Right now fusion reactors would seem to be the very cutting edge of engine types for use in space travel. There have been many different proposals on how we should travel through space over the years. Some have suggested solar sails, others have suggested electric engines which are also known as ion engines and some have even suggested hitching a ride with one of the heavenly bodies heading towards our destination. Jules Vern the famous science-fiction writer suggested shooting manned space capsules out of a cannon and 100 years later it is being thought of again. As a matter of fact some scientists claim this to be the most economical way to launch from the moon since it has low gravity. They are not talking about a cannon in the sense Vern was, but they are talking about something more equivalent to a railgun which would use the concept of opposing magnetic force.
I am only talking about things we know for sure right now, that is why am not getting into antigravity propulsion since many people don’t believe we have it yet. Just to make the record clear however I think we do and I think we have been working on it for many decades. If we can’t find a way to shield our ships from radiation than the whole concept of manned space exploration will go down the tubes. There is however at least one other solution that uses current technology. That solution would be to build our ships in space, then it wouldn’t matter how much lead we lined the walls with since the weight would no longer affect anything. The reason we can’t do this on earth is the shielding we would need would be so heavy we wouldn’t have rockets big enough to launch the heavy spacecraft.
Perhaps somebody will figure out how to use the fusion reactor not only as a power source to propel our spacecraft, but also as a source for some sort of an electrical shield. Right now that would be a very good solution, but unfortunately we don’t know how to make this yield or if it would even work. It would have to be capable of repelling radioactive particles. A fusion reactor would make the trip to the moon a piece of cake. Conceivably it could take less time to get to the moon using one of these rockets than to fly from New York to Australia. We are going to have to be very careful with fusion rockets and make sure we don’t contaminate our space with radioactivity. The next 20 years or so is going to be very exciting for anyone who is alive at that time and who is interested in space travel.
