On Wed, 09 Jul 2003 22:25:06 -0700, Hop David
<hopspage@[EMAIL PROTECTED]
> wrote:
>
>
> Erik Max Francis wrote:
>> GrapeApe wrote:
>>
>>
>>> Intuition lies, but mine tells me that such a solar sail would never
>>> even get
>>> the first puff of solar wind within them. I may side with the New
>>> Scientist
>>> until there is a working prototype.
>
> The New Scientist article used the spinning of a Crookes Radiometer as
> evidence of Gold's claim. The devices down here aren't really in a
> vacuum. The thin air on the dark side expands from heat and pushes the
> radiometer. I'm told if the device were opened to the vacuum of outer
> space light pressure would dominate and the wheel would spin the other
> way.
>
> Henry Spencer has cited the example of Radarsat 1, which has a sun-
> synchronous orbit. Continuous sunlight pushes it's solar arrays and
radar
> antenna towards the earth. 2/3 of its station keeping fuel needs to be
> used to counteract this push, an effect its designers hadn't expected. I
> believe acceleration due to light pressure is already well supported
with
> empirical evidence.
The solution is simple: Just slow it down in its orbit just enough so
that the pull of the sun's gravity will balance the push of the
sunlight!
