## Simulating a solar sail

What did you draw?
FleetFoot
Posts: 2
Joined: Tue Jun 04, 2019 5:47 pm

### Simulating a solar sail

I'm completely new to this site and a search of the forum didn't turn up anything on this topic, my apologies if I've missed a previous answer. I'd like to simulate the motion of a body with a small mass but also being pulled by a solar sail, i.e. subject to gravity but also with an additional force. Is this possible?

Best regards
George

testtubegames
Posts: 1078
Joined: Mon Nov 19, 2012 7:54 pm

### Re: Simulating a solar sail

Hmm, the sim isn't designed with solar sails in mind, so I'm not exactly sure. It depends on what it would mean to simulate a solar sail.

I think the closest you could get would be to build a solar system with just a star and your 'solar sail'. Then modify the force of gravity (in a way that would require the full version) to add in some value to represent the force from light. So something like Force ~ -1/r^2 + Force_sail. I imagine the force on a sail goes as r^-2 as well, but repulsive instead of attractive.

If you want a more detailed simulation than that, I can't think of a way to do it with the system... you wouldn't be able to steer, say (though you *can* add a tangential force... actually, hmm... maybe that would work), and you're limited by the fact that all object push on each other with the same force law. So if you added other planets, everything would be getting pushed by light, and pushing other objects as if they were a strong light source.

If you've got specific questions on what the sim can do, I'm happy to field them.

FleetFoot
Posts: 2
Joined: Tue Jun 04, 2019 5:47 pm

### Re: Simulating a solar sail

TTG: Force ~ -1/r^2 + Force_sail.

Yes, the sail force depends on r^-2 but also on the sail area and the angle of incidence of the light on the sail.

TTG: ... you're limited by the fact that all object push on each other with the same force law. So if you added other planets, everything would be getting pushed by light

That answers my question, I'd want to add a constant vector force to one body in the manner you suggest but not to any other body. Thanks for the quick and simple response.

George