[ExI] Fuel synthesis, power sats and low cost transport to GEO.

[hkhenson]

I know there are not too many technical people on the list, but if 
you are up on chemical engineering, power sats, crude economics, 
rocket science, laser propulsion, orbital mechanics,geometry, 
geography, physics and/or math, I would appreciate comments on this:

www.operatingthetan.com/SpaceBasedSolarPower/March18Talk.ppt

The notes were left off the orbital mechanics slides.

The problem is geometry and time.  The minimum energy transfer orbit 
in the first slide is about 5 hours.  That puts the laser focusing 
bounce mirrors in the wrong place to circularize at GEO.

So the solution (suggested by Jordin Kare) was to put it in a 
considerably larger orbit, 70,000 km apogee, which takes 12 
hrs.  Then the mirror is in a place where it can take perigee up to 
GEO.  The resulting transfer time back to GEO (perigee) is about 22 
hrs so the when it come around the bounce mirrors are in the right 
place to drop apogee to GEO.  It takes 3 burns instead of two, but 
the total delta v should close.  (One set of mirrors reduces cost and 
military threat.)

There is also a big Exel spreadsheet that models the rocket and laser 
performance you can ask for.  I am not sure constant acceleration 
with the laser is the most efficient use of laser and laser stage 
mass but I have not had time to explore making the exhaust velocity 
equal to the stage velocity to see if it makes a difference.  (In 
theory this is most energy efficient.)

Keith