Re: starship-design: HOTOL SeaDragon idea.

[ben franchuk <bfranchuk@jetnet.ab.ca>]

KellySt@aol.com wrote:
> 320 isp with LOx/LH??  Thats hardly better then the numbers for the 
> LOx/Kerosine engines of the '60's?  Its actually worse then the current gen 
> of LOx/Kero engines which get up to 350 isp!  Shuttle LOx/LH engines get 
> about 450isp!
> A 747 has a empty weight about half its max takeoff weight.  Course it has to 
> takeoff at slower speeds.  I think lift is one of those V^2 things.  Given 
> the size of this monster, it can handal light seas at speed.  Probably lift 
> off into its ground effect, then run up into far high speeds for assent.  
> (lots of open ocean out there.)  So possibly tripling its speed to 450-500ish 
> mph could get you 9 times the take off weight?  That big Russuan surface 
> effect ship had numbers like that.
The problem with Rocket design is because things are so sensitive to
the isp factor a minor change can throw a design right out the window.
I think a smallish designed craft can be optinum for mass/payload in
the 800 kg/2400 kg range providing the second stage is unmanned to
a fixed space platform. Has any work on a third stage using microwave
or solar powered engine that stays in orbit and captures the second
stage?
1st stage -- air breathing/wings manned
2nd stage -- payload pod /winged reentry
3rd stage == booster shuttle/space frame
Ben.