[ExI] Explaining technical matters

[BillK]

On Fri, Aug 10, 2012 at 11:25 AM, Keith Henson wrote:
> For a 20% structure fraction, a laser heated hydrogen vehicle gets
> ~25% to LEO, water heated to the same temperature gets -11% to orbit
> (both cases starting at 2 km/s).
>
> Hydrogen has been used in big rockets all the way back to the second
> stage of the Saturn V.  It isn't _that_ hard to work with.  In fact,
> the hydrogen load in a Skylon is a few tons less than was used in the
> Saturn V second stage.
>
> The difference is we would be flying 3 times an hour.
>
> ^^^^^^^^^^^^^^^^^^^^
>
> I don't know how to express non-linear equations to where the masses
> (or even technically astute people) are going to appreciate the
> difference in performance between laser heated water and laser heated
> hydrogen without looking into the "rocket science" of the situation.
>
>

I'm not sure what you are asking for, but how about.......

Produce tables showing samples of each type of rocket with various
starting weights and weight delivered to LEO and laser energy
consumed.
You could add intermediate stages showing rocket speed and remaining
weight of fuel and energy consumed so far.

The differences between the rocket fuel methods should be obvious.

(Or are you asking for an explanation that avoids calculating the above tables?)

This sounds like a Spike spreadsheet special.   ;)


BillK