Solar polar hovering sail

[aero]

Hi - I read a very brief note re- a solar sail application of hovering in the photon stream above the solar pole. I guess a sail system should be able to hover at any latitude if it can hover above the pole, but observation of the sun's pole is of interest. Thing is, the article basically said, "This would be a good application," (I don't have the link) but it wasn't very helpful in designing the sail. My gut feel is that the sail would be neutrally stable, if it worked at all. What do you think?

I'm thinking of a parachute type of solar sail with a suspended payload. The sail is spinning around the gravity axis with centrifugal force keeping it open and wings around the circumference to keep it spinning and to control the lift. This is done by spinning faster and slower to expand and contract the surface area for more or less lift. The reason I thing it might be neutrally stable is that weight and lift are both inverse square functions of radius. Then wouldn't the performance be the same at 0.1 AU and 1.0 AU? In other words, couldn't the system be tested at a distance convenient to earth, without the bother of moving it to a low polar altitude? Of course the lift would also be a function of the spin rate because it is normal to the surface but the normal vectors across the sail are not all pointing sunward and change direction as spin rate changes. Is a circular spinning sail the best solution?

[scienceguy]

Do you have a diagram?

[aero]

Do you have a diagram?

No. I haven't made one. In my mind I visualize it as looking much like a parachute with wings about the circumference. The wings are panels held in place with lines to the risers and are the control surfaces of the sail. I don't know if some of the wings can be in a fixed orientation or if they all need to be actively controlled.

The thing is, I don't know enough about solar sails to make a drawing of one that has a reasonable chance of working, I and I know that I don't know, so ... I was hoping we could discuss the idea and perhaps come up with something that might work structurally, be controllable, and with enough lift to suspend a working payload. Maybe an estimate of a useful payload mass would be a place to start.

[Lampyridae]

This is one of the applications seriously considered for a solar sail. In it, the sail orbits the polar axis at several thousand km altitude, with light pressure holding up the rest.