Neskiairti wrote:wait.. 5 days to reach mars at 0.3g acceleration? O.o you sure about that?
Pretty sure.
I did miss speak about something though, I meant a maximum burn of 0.5g, the ship to mars could never hold enough fuel to burn half way there, then decelerate a constant burn the other half
If we take fuel into consideration, matters get a lot more complicated. In Tadpole, the ship can maintain 0.3 G's continuously, day and night, for long trips. This is the basic assumption, which simplifies the math. In fact, you could say that the acceleration near the middle of the trip is "wasted", since the ship will soon turn around to decelerate; BUT, in any real trip there's a curve to follow, due to the velocity of the base you leave from, and having to match velocity with the base you're going to; so it's possible to use the region of the middle of the trip to make course adjustment; so the turn-around can be gradual and useful.
I decided to break down and do the math...
at its closest, mars is roughly 55million kilometers away.
maybe my math is rusty but to burn a constant 3 m/s^2 until say 27.5million kilometers takes 5.25 days... so close to 11 day trip with fully mirrored deceleration.
Let's see...
S = 1/2 a t^2, so
t^2 = 2 S / a
t = sqrt( 2 S / a ) = sqrt( 2 * 27.5Gm / 3m/s^2 ) = sqrt( 18.333Gs^2 ) = 135.4ks = 2.2566 kilo-minutes = 37.6 hours for the acceleration phase, and another 37.6 hours for deceleration, for a total of 75.22 hours.
75.22 / 24 = 3.134 days.
I think the reason we came up with 5 days was that originally we were going to use 0.25G as the maximum acceleration, and then we changed our minds but forgot to recalculate.
I was however not referring to some constant acceleration, but maximum accelerations. From the way I see it, most trips in space will consist of an acceleration phase, a cruising phases, then deceleration phase.. and possibly some turning phases during cruising to avoid gravity wells and what not.
That is indeed the current paradigm; but if energy was plentiful (helium 3 fusion), but thrust limited by thruster technology and strength of materials, you might want to spread the acceleration in time, rather than accelerate at 40G's for a few minutes, then coast, then decelerate at 40G's for a few minutes.
Constant acceleration has another advantage: It creates artificial gravity for the crew.
Now an acceleration phase with a peak of 2G is not impossible, nor is it unreasonable. I used the shuttle as an example, because that is a great example of acceleration phase followed by cruising phase. Once its boosters break off, its mostly down to maneuvering.
Sure. 2 G is not impossible; but it probably will always take chemical fuel to do that, where fuel and propellant are one and the same. The propellant generates its own energy by burning. In a paradigm where you are accelerating propellant using a separate energy source, such as a fusion power plant, that's a whole different ball game. Secondly, even with chemical propulsion, you have a maximum temperature the burn chamber can take, which limits your efficiency, and dictates that you cannot expel tiny amounts of that propellant at near the speed of light; you've got a limit for that speed, dictated by temperature limit, and the only way you can produce high thrust is by increasing the mass of propellant you expel per unit of time. So you go through your propellant pretty quickly.
With an ion engine or vasimr, you have a different situation, where the limit is in the watts of throughput, but you can hike the propellant efficiency a lot, because you can expel it up to potentially near c, at a low mass rate. So you'd probably want to use constant accel, or much closer to constan than with chemical thrusters, anyways.
the actual numbers really mean diddly squat anyway, its about how the game feels. the numbers just 'look' good to players. I already went on about that though.
False.
This is no way to address any subject, --to base things on "feelings".
Everyone's feelings are different. 'Numbers' is the name of the game.
Well, eventually yes, there's a 'feelings factor', but that should be the consideration at the highest levels of game design.
You cannot work under the premise of 'feelings rule' at every low level step of the way; such a policy ruins everything.
As I said many times, a space game needs some kind of handwavium technology to shorten trip times. That's a given.
However, what you REALLY DON'T want to do is fudge things and mess with everything. Keep the handwavium well
encapsulated. Let everything in the game be realistic and consistent with physics and the natural limits of technology;
and then introduce JUST ONE THING, such as SPEC, that solves the problem of time, as elegantly as possible. But you'd
end up with total crap if you a) make interplanetary distances shorter, b) allow huge accelerations, c) secretly compress
time, AND d) add SPEC. Then you've got a cacophony; an incomprehensible mess nobody can understand and work with.