View Single Post
Old 10-25-2009, 07:02 PM   #8
Join Date: Jun 2006
Default Re: [Spaceships] Fuel versus reaction mass

Originally Posted by Langy View Post
The problem with this (and all antimatter ship designs) is that antimatter storage is heavy.
This has always been the killer for antimatter power storage designs. We simply don't know a good way to store it where the energy tied up in the storage system isn't comparable to the energy content of the antimatter. And since we have to keep the storage system from tearing itself apart with stuff held together with chemical bonds, the storage system ends up weighing something comparable to an amount of chemical fuel containing hte same energy, which rather defeats the purpose.

I'd note that converting a space drive to an air-ram is fundamentally a poor idea for any drive where the energy supply has significant costs. Any drive has a thrust proportional to mass flow times square root (power consumption). What an air ram amounts to is taking an engine designed to use the least mass (and hence most power) possible and running it where mass is essentially free. In a sense, you are using the energy in the least efficient way your engineers are capable of arranging. If energy is not so cheap that the lifetime cost of the waste is less than the cost associated with keeping a second vehicle designed as an aircraft, or a second engine, it's a losing proposition.
MA Lloyd
malloyd is offline   Reply With Quote