Solar Sail???????

TerryM · #1 January 8th, 2001, 12:56 AM

Actually a solar sail uses the solar 'wind' to drive the ship. Course it has to be BIG to make any difference.

And it could be used for braking when entering a solar system.

But for game purposes, I like to think of it as that big-ballon type thing (can't think of the name) racing yatchs use on the downwind leg of the race course...

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TerryM

Baron Munchausen · #2 January 8th, 2001, 02:33 AM

Yes, a 'Solar Sail' in fact uses the solar wind as much as the pressure of light. Close to a star, the solar wind is much stronger. Farther out, the light would contribute more of the push. The thing is, it is VERY slow to build up speed and as everyone else has pointed out it can only work moving AWAY from the star. If there's one thing all races must have developed by the time this game occurs, it's space ship engines that let you go more or less directly from one place to another. Having to loop around a solar system a dozen times like the Cassini probe has been doing would be incredibly annoying.

There is a new type of 'Solar Sail' in the works, btw. It's totally dependent on solar wind since it's magnetic rather than a big sheet of pLastic or something like that. It turns out you can just create a big magnetic field around your ship and pump out some plasma into it. The magnetic "drag" of the solar wind hitting this works just as well as the physical "sail" type of propulsion but you don't have to worry whether it will get all tangled up when you try to deploy after launch and it won't get torn by micro-meteors. Otherwise it's still a solar sail and only works in one direction. Great for primitives like us to send probes into the distant reaches of the solar system. Not worth anything to anyone who has high-velocity propulsion systems already and doesn't have to loop-the-loop around the solar system to get anywhere.

apache · #3 January 8th, 2001, 04:22 AM

Well, lets remember we are also using planet destroying weapons, things that 'collapse' black holes, and quantum reactors that can create infinite energy.
A solar sail definitely needs a star nearby to work. I also know that using Newtonian principles, you can definitely get the sail to work in at least a 180 degree arc of movement. Using a magnetic sail would result in the ability to move in a full 360 degrees (ie: both away and towards the star).
Now, as has already been mentioned, there is no such thing as drag in a vacuum. This is true, but much of space is not a total vacuum. A nebula, obviously, is a large area comprised of stellar gasses, and most certainly would create drag. A solar wind also creates a 'drag' force on an object in space, though it requires a very large ship and/or long distances to affect it noticeably. It also depends on direction of motion as to whether it is actually a drag force or a propelling force (the original principle of a solar sail).
So my point is that the solar sail is actually less ridiculous than a quantum reactor or 'collapsing' a black hole, so it should stay in the game. However, it should definitely not be allowed to work in nebula and black hole sectors.

Puke · #4 January 8th, 2001, 04:35 AM

quote:
Originally posted by apache:
the solar sail is actually less ridiculous than a quantum reactor or 'collapsing' a black hole, so it should stay in the game. However, it should definitely not be allowed to work in nebula and black hole sectors.

but working on magnetic pricipals as you say, or working on other field / wave related principals it could function without a star. granted, it might have a hard time in deep space, but if nebulae are cool enough to disable shields or sensors then they certainly have enough background radiation puttering about to power a sail. we have definitly observed black holes cranking out all kinds of radio / microwave / high frequency wave output, so they should not have any problem powering a sail either.

as someone else pointed out, the simple answer is to look at it a little more abstractly, and maybe change the description from 'bounces photons at 90 degrees to generate force' to something more like 'manipulates naturally occuring fields and background radiation to indirectly propell a ship.'

Emperor Zodd · #5 January 8th, 2001, 05:10 AM

I think the solar sail should only work when a ship runs out of fuel. And should be standard technology to all races. Then that would give ships a reason for still being able to move 1 space when they run out of fuel.

Marik Wahoooka · #6 January 8th, 2001, 06:08 AM

Actually, you can't get a 180 arc of motion with a solar sail. Sailing on earth only works because of the resistance the water provides against the hull. Without that force, all boats would always move in the direction of the wind. In the case of space, there isn't anything providing that restoring force, so the ability to use only a component of the force goes bye-bye.

Pity though... Solar sails just seem so frickin cool. Of course, if they are picking up distant stars, one could set them to pick up certain wavelengths and then coast in what ever direction you wished simply by finding a proper star and tuning the receptors to it. Hm...

I'll build an intergalactic spaceship, try it out, and get back to you.

Jubala · #7 January 8th, 2001, 06:52 AM

quote:
Originally posted by Marik Wahoooka:
I'll build an intergalactic spaceship, try it out, and get back to you.

And was the Last ever heard from Marik Wahooka...