Re: Orbit B

[Kevin C Houston <hous0042@maroon.tc.umn.edu>]

Kelly:
> Kevin:
> > No, think of a cone twelve light-years tall, with a base circle the size 
> > of merc's orbit.  the angular deviations would be nearly 
> > impossible to measure.  Let's just consider a 
> > two-dimensional analogy. an isoceles triangle twelve 
> > lightyears to a side, with a 72 million mile base:====
> 
> 
> Lets consider that if the beam is 72 million miles across, and the sail is 10
> thousand miles across; and the ship needs e18 watts of beam to hit the sail.
>  The total power over the entire beam would need to be about e25 watts.  I
> think we are starting to outpower the sun here Kevin.

No, the beam is not 72 million miles wide, silly.  the entire cone is 72 
million miles wide at the base.  go back to the two dimensional analogy, 
the beam starts on one leg of the triangle, stays there for 44 days (half 
of merc's orbital period) then switches to the other leg for 44 days.  in 
both positions, it's beam width is only slightly bigger than the sail. 
(to overcome jitter effects).  

Switching back to the three dimensional world, the beam would have a 
radius 650 Km larger than the radius of the Asimov's sail.  (that being 
the maximum amount of jitter that a gyro stabilized system could produce)
as Mercury sweeps out it's orbit, tracking stations at the south polar 
transmission center keep it pointed at TC.  because the height of the 
cone is orders of magnitude greater than the length of the base, there 
would be very little effect on the Asimov.

Kevin

P.S.  I'm not going to respond to the solar/conventional power argument 
in this newsletter, we gots enough mail as it is.