Re: minsky vs solar sails

Doug Jones (
Sat, 24 Jul 1999 10:24:33 -0700

Mariner 10 tilted its solar panels to null our sunlight torque and reduce propellant consumption, ca 1973.

As for spacecraft lasting more than decades, radiation exposure in space degrades solar cells by inducing crystal dislocations. The dopants diffuse to the flaws, and the efficiency drops several percent per year. I don't think there is a floor to this process, but if you can periodically anneal the cells by heating to around 250 C, the radiation damage is greatly reduced.

Trouble is, this would require some moving parts to scan a magnifying glass over the panels to do the annealing. As far as I knoe, it's never been done.

It's difficult to do this for the control electronics, though they don't degrade as quickly as the solar arrays.

Technotranscendence wrote:

> >Satellites with solar sails and gyrodynes could have very very long
> >lifespans. Things should be built to last thousands of years.
> If my memory's correct, NASA already did have at least one
> satellite with panels on it that used light pressure to maneuver.
> This was in Earth orbit.
> Anybody else recall this?

Doug Jones, Freelance Rocket Plumber