🚀 go-pugleaf

Well, so solar sails are just "driven by radiation pressure".  I'd heard
that (as well as solar wind) before.  

However, If you look at the original post, you'll see my concern -- 
radiation pressure seems 2-3 orders of magnitude too small to be useful
for drive.  Recalling that F=P/c for light pressure, and that power
density P is roughly 1.4kW/m^2 at Earth orbit, you get a pretty trivial
4.7 MICRONEWTONS per square meter.

Even if you are satisfied with 0.001G (0.01m/s^2) of acceleration, this
means your sail material must mass less than 0.5 GRAMS per square meter.
Is this feasible?  I recall seeing some discussion on solar sails for the
proposed 1992 solar sail race to Mars -- surely someone can post, or
email me, some hard numbers on this?  I'm just having difficulty convincing
myself that solar radiation pressure is strong enough for this purpose.

Disclaimer:  All opinions expressed are my own, and do not reflect the 
     position of Intel, Portland State University, or Zippy the Pinhead.  
============================================================================
Jeff Greason                  "You lock the door ... And throw away the key.
  <greason@ptdcs2.intel.com>   There's someone in my head, but it's not me."
  <jeffg@eecs.ee.pdx.edu>				-- Pink Floyd