Another request for patch

[Kuokkanen]

Just got an idea. How about add another option for even more realistic flight physics which negates effect of vlimit parameter? At least I would like to zoom with fighter at 10 kilometers per second towards enemy starship and release missile payload.

[Pheonix Starflare]

I feel like milo once said the SS engine gets screwy at speeds approaching that, but I'm not positive.
As a work-around, couldnt you set you're vlimit to like 3e8?

[Kuokkanen]

ORIGINAL: Pheonix Starflare

As a work-around, couldnt you set you're vlimit to like 3e8?

First you need to tell me how I extract milo's .DAT files.

[Pheonix Starflare]

Ohh, i didnt realize you wanted to do this with milo's ships, i thought you were making a mod. My bad.

[John DiCamillo]

ORIGINAL: Matti Kuokkanen

Just got an idea. How about add another option for even more realistic flight physics which negates effect of vlimit parameter? At least I would like to zoom with fighter at 10 kilometers per second towards enemy starship and release missile payload.

No, that would not be more "realistic" than the way it works now. The vlimit parameter exists A) to make the game more fun and B) to compensate for the fact that the physics engine is not tracking reaction mass. Real world reaction motors (i.e. rockets) can not accelerate a vehicle indefinitely. Eventually they will run out of material to throw away.

If you want to create mod ships which have very high vlimits you can do so. I remember that Dragon Lady was working on just such a mod a couple of years ago, but I don't know how that turned out for her.

[iconoclast107]

[ Real world reaction motors (i.e. rockets) can not accelerate a vehicle indefinitely. Eventually they will run out of material to throw away.


That's true but what really limits a spacecraft's acceleration/speed is the speed at which the mass exits the engine. If I recall correctly (i used to be in aerospace engineering classes til the calculus got the better of me) the speed which you can accelerate to is roughly twice the speed of the stuff flying out the back of your engine. Of course, if you don't have enough fuel to begin with thats a seperate problem altogether.

[TheDeadlyShoe]

I never found that to make much sense at all. Why would it matter how "fast" you are going so far as an engine is concerned? Within the reference frame of the ship (and thus the engine), your speed doesnt change at all. Unless the problem is drag.

??

[HenryK]

That rule is most likely a principle of fluid dynamics that has no meaning whatsoever in space.

[John DiCamillo]

I'm pretty sure that it is simply a rule of thumb. In order for the vessel to exceed its own exhaust velocity it must throw away at least half its initial mass as reaction mass. And that is assuming that it dumps the entire load in one instantaneous burst, such that none of the energy is used to accelerate the reaction mass, and also that none of the fuel needed to be converted into energy. If you burn the fuel over time, the amount of initial mass that must be thrown away as reaction mass goes up significantly.

All of that reaction mass must be housed in some kind of structure, which adds to the non-useful part of the vessel. This is why orbital rockets are built in stages - you get to throw away all of the dead weight needed to contain a significant portion of the fuel supply as soon as you have burned off the fuel and emptied the tank. If you are lucky, you can throw away the first stage in some reusable manner like the SRBs on the space shuttle, or Space Ship 1's mothership aircraft.

Note that all of these considerations change if your ship can pick up additional reaction mass from the environment during flight as in the case of a Bussard ramscoop.

By the way, the exhaust velocity rule of thumb was where I got the initial idea to implement a soft vlimit. One problem with the vlimit from a realism perspective is that it is anisotropic. The vlimit only reduces the ability of the engines to accelerate you further in the direction of motion. You can change direction or slow down much more quickly than you can continue to speed up. I have no explanation for that behavior except that it just seemed to make combat more fun when I was designing and playtesting the game.

[Kuokkanen]

I'm getting confused about about stuff of reaction mass and the like. Maybe I know that terminology for finnish but not english...

Anyway I thought in space acceleration is not reduced until at 10% of c (speed of light) where mass starts increasing. This is (or so I have heard) in Einstein's theory of relativity. Object going as fast as c has infinite mass.

ORIGINAL: John DiCamillo

By the way, the exhaust velocity rule of thumb was where I got the initial idea to implement a soft vlimit. One problem with the vlimit from a realism perspective is that it is anisotropic. The vlimit only reduces the ability of the engines to accelerate you further in the direction of motion. You can change direction or slow down much more quickly than you can continue to speed up. I have no explanation for that behavior except that it just seemed to make combat more fun when I was designing and playtesting the game.

I for one liked Frontier's dog fights, though hostile enemy without weapons simply tried ram. Indeed I would love to give it try in Starshatter. All right, maybe I make my own mod some day.