Re:SpaceX reprioritized to cyber defense and overcoming sign...
by rocqua on Sunday March 06, 2022 @02:18AM
(#30575702)
The math here is doable. Approximately the inner angle of the cone of light comming from a laser beam is 1.22 2lamda/d (source: airy disk wikipedia). Where lamda is wavelength and d is the aperture.
Lets pick lamda so 1.222lamda is 1000nm (blueish light). Then by smal angle approximation, the size of a beam at 500km (starlink height) is 500km * 1000nm / d
Say we want our beam to be 50m wide. That gives an aperture requirement of 1cm.
Huh, that seems reasonable. So in a vacuum, it could perhaps be done. Atmospheric effects would make this worse ofcourse. And a 50m beam is not going to dump much heat, but it seems somewhat plausible in the near future.
Lets pick lamda so 1.222lamda is 1000nm (blueish light). Then by smal angle approximation, the size of a beam at 500km (starlink height) is 500km * 1000nm / d
Say we want our beam to be 50m wide. That gives an aperture requirement of 1cm.
Huh, that seems reasonable. So in a vacuum, it could perhaps be done. Atmospheric effects would make this worse ofcourse. And a 50m beam is not going to dump much heat, but it seems somewhat plausible in the near future.