Solar Sails - WIP

[Eskarina]

The thing about solar salis, is that although they are slow to catch up decent speeds, they ARE capable of reach decent speeds. A starship built around a solar sail must be planned around the very sail. That means minimum fuel, minimum engines, and minimum total mass. Yes I will be slow, but eventually it will catch up, and that means that as long as you have a star at your destination, you don't need an engine to move around at all

This is a typical maneuver around the star. Since the photon "wind" is more noticeable when you are closer to the star, you need to arrange a close flyby around, every time you want to catch up escape speed. And more importantly, they are unable to reach the deeps of a solar system without gravitational assists.

BUT it have it's strenghts

A human manned interplanetary ship that travels to Mars and back, must employ 99% of his mass in carrying around the required fuel, with all his stages combined

And:

A typical ship with solar sails, it should be capable of reach speeds of 30km/s in a one year travel, with constant acceleration along his way. New materials should be able to reach final escape speeds of 100km/s and depending on the application of new materials, even 1000/km/s

So maybe they are slow to speed up, but they are very capable of speed up a lot. The issue then is in a game as kerbal, they are fun to use.

Okay, now that I placed some science stuff, I want to join this group. I think they should be in the game. And my recommendations are:

The mod presents a very clever solutions to implement "alpha" solar sails, but if I'll made some changes, there were:

1º. Engine and "fuel containers" should be removed

2º. Decent solar models, textures and animations for the parts (I cand do this! )

3º. Solar sails should be slow to catch up, okay, but maybe they must be NOT SO SLOW to catch up that they are zero fun.

4º. In my opinon, they must have an efficency equal or higher of the ion engines, closer to the sun, and lost their efficency quickly when they are far away, as real sails do.

Distance (m) Power Example

00,000,000,000 10x Kerbol

13,599,840,256 1x Kerbin's orbit

68,773,560,320 0.5x Jool's semi-major axis

206,000,000,000 0x Almost 3x Jool's orbit

A good compromise should be x10 the trust of the ion engine around the sun, x1 to kerbin distance, and then x0.1 from there and beyond. Since solar sails are fuelless, this should make a good compromise. I dunno if the current mods state allows for such calculations and operating parameters. BUT a piece of equipment that delivers the power of 10 ion engines around Kerbol, is enought to make it worthwhile, even if they have such limited radius. AND with a solar sail in your ship, you'll always have an emergency engine to trip back to kerbin (maybe slow, but good )

AND ofc they are angle / dependant, and of course they should be able to apply his magic in time warp x4.

Edited September 27, 2013 by Eskarina

[frizzank]

A plugin to allow for thrusting during time warp would be necessary. No one is going to do an actual 3 month burn time. I doubt most people would wait longer than a few min in realtime for a burn. Otherwise even at 4x speed your waiting 3 months for a year long burn. This would also help other low impulse engine types, ion, laser, bussard ram scoop, if it were created.

[Eskarina]

A year long burn will only be useful to reach kerbol escape speeds (already not implemented).

[ashtronic]

maybe the photon effect should be modded to be constantly applied while the mod is activated, ie like visual light effects from the sun, to separate it from being reliable on certain part or engine?

[Tanya Sapien]

all those are great ideas. Currently I'm working on a Helium3 plugin for Kethane, but I could go back and work on these again. As of right now, I'm trying to learn how to make my own custom meshes so that I don't have to borrow stuff from other modders (read as: Kosmos)

once I've figured out how to code up my own material stuffs, I may come back to this community project and give help to it, but as of now I'm not currently working on it.

also, to the person who said the propulsion should only be able to be directly away from the star, that would make them largely useless in KSP. I think building them around the properties of atmospheric sails (AoA, deflection) would make them more fun to work with.

[p1t1o]

Oh jesus-H, I just read that typo on the first page.. All I can say is well done sir! Made my day :D:D

And just to stay on topic:

I can't remember where I read it, but there is a concept called a "statite" which is basically a satellite that is stationary relative to the sun (ie: it doesn't have to be in orbit) that is held at a constant altitude by a solar sail.

Surprisingly, you don't need that big of a sail (IIRC its on the order of tens of square metres per kilogram, not sure exactly) and the same size sail works at any altitude (gravity tails off at the same rate as light intensity).

What this also means is that you can put a sail on a sattelite, and you effectively decrease the required velocity to achieve orbit at a given altitude, all the way down to zero, depending on the size.

Or, you could build a series of satel/statites that all have the same period, but different altitudes.

All that only works if the body you are orbiting is a star though.

Edited November 2, 2013 by p1t1o
clarity