Actually About STL-Only Interstellar Travel

David Johnston2 · 09-05-2010, 04:01 PM

As I was saying, in order to reach ramjetting speed, you'd need about 9 tanks of reaction mass minimum, which plus the other required systems, would leave you with about one spare section that you could use for sensors or cargo or a second habitat or something. That's by the book which doesn't take into account that the density of the interstellar medium varies and Sol happens to be plopped right in the middle of a bubble of thin medium.

It's actually unlikely that a Bussard ramjet could get a ship up to relativistic speed. The faster you go, the more energy you have spend on accelerating the gas you are taking in by ramjet. This creates drag that will balance your thrust. I seem to vaguely recall 17% C as a maximum figure, but I have no idea how they calculated it. It would depend on how fast your maximum exhaust speed was.

Of course with a realistic fusion torch it would take a very long time to accelerate up to that maximum in the first place. If you were just hopping between nearby suns, you'd need a superscience reaction drive. Really reactionless drive would be an awful lot easier.

09-05-2010, 04:01 PM	#1
David Johnston2 Join Date: Dec 2007	Actually About STL-Only Interstellar Travel As I was saying, in order to reach ramjetting speed, you'd need about 9 tanks of reaction mass minimum, which plus the other required systems, would leave you with about one spare section that you could use for sensors or cargo or a second habitat or something. That's by the book which doesn't take into account that the density of the interstellar medium varies and Sol happens to be plopped right in the middle of a bubble of thin medium. It's actually unlikely that a Bussard ramjet could get a ship up to relativistic speed. The faster you go, the more energy you have spend on accelerating the gas you are taking in by ramjet. This creates drag that will balance your thrust. I seem to vaguely recall 17% C as a maximum figure, but I have no idea how they calculated it. It would depend on how fast your maximum exhaust speed was. Of course with a realistic fusion torch it would take a very long time to accelerate up to that maximum in the first place. If you were just hopping between nearby suns, you'd need a superscience reaction drive. Really reactionless drive would be an awful lot easier.