Resources ainherently limited, near term (was The three challenges)

On Mar 21, 2012, at 3:35 AM, hitssquad wrote:

>
> --- In spacesettlers@yahoogroups.com, sraj wrote:
> > All rocket systems must use only Oxygen and Hydrogen.
>
> Hydrogen is a poor fuel to launch with. It gives little thrust,
> because of its low density.
>
Hydrogen/Oxygen rockets have the best ISP of any current launch
system. You can do a little better with Hydrogen/Flourine or Ozone,
but not much. Thus, H2/O2 is the bets rocket fuel. The reaction
mass is mostly water.