🚀 go-pugleaf

In article <1992Oct28.165504.15346@ptdcs2.intel.com> greason@ptdcs2.intel.com (Jeff Greason ~) writes:
>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.

Yes, that's the right sort of number.  Solar sails have to be very big
and very light, and they accelerate slowly.

>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? ...

About 0.14g/m^2 is feasible (50nm aluminum) even without going to exotic
approaches like perforated sails.  But in practice, first-generation designs
usually settle for rather lower accelerations.	
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MS-DOS is the OS/360 of the 1980s.      | Henry Spencer @ U of Toronto Zoology
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