[gurps] [VEHICLE] of the week 674 – Improved Spaceplane

[Zan Lynx]

On Wed, 2007-09-26 at 12:48 -0600, Wyrm wrote:
> Onno Meyer wrote:
[snip]
> Reentry takes the 
> > spaceplane into the upper atmosphere, where drag brings it down for a 
> > dead stick landing.
> >   The turbofans burn 1,200 gallons of jet fuel per hour and the rockets 
> > burn 1,375 gallons of HO per second. A full load of fuel is $23,600.
> 
> Why a dead stick? Can't the turbofans be used for landing as well?

Every gallon of jet fuel you don't burn has to be carried to orbit by
the rockets and comes directly out of your payload weight.  I wouldn't
be surprised if the jets are run at full power right up to the last of
the fuel, before rocket ignition.

Just like commercial airlines don't load all the fuel they can carry.
Extra weight doesn't pay.
-- 
Zan Lynx <zlynx at acm.org>