Problem of math

[Harmon]

Need some help here, hope you all might be able to help out-

For the longest of times I have wanted to start a campaign in space. The idea is that some thousand or so years in the future mankind has ventured to a nearby system, for reasons that are campaign based (I have Players that post and read here so please, lets not spoil it for anyone) the FTL drives are gone, no longer accessible to anyone.

My problem is however that the system is 2 LY across (2 light years in diameter), but I want the characters ship to be able to venture from the core planets (1+ or – AU) to the outer space stations (1 LY out) in a reasonable amount of time- perhaps a few weeks or even as much as two months. Now the issue that I am having is that to do that the ship (and by default all space ships should have close speeds, though some will be slower and some faster) the PCs have I do not want to be able to do faster then about Mach 10 in atmosphere, while keeping them in the system (“hay, we can do 1 LY in X number of weeks that means 6 LY in X times 6 so we could be to the Terran system in G number of weeks”).

Question- How do I accomplish my desired ship speed without seemingly being to much of an ass as a GM?

 

[CRGreathouse]

You'll need to use a different propulsion system for long-range trips. Some form of hyperspace folding (either bending higher dimensions or using existing bends,then traveling across) would work nicely. Failing that, a mystimagical system where you can 'blink' in and out, perhaps after charging for many hours, between predetermined points... this would allow you to have nonlinear travel, insofar as the shortest distance between two points might be a third point more distant from either than the other.

 

[Treebore]

In Traveller the space ships often cannot go into atmosphere without an extra expensive hull that is aerodynamic. In space you aren't worried about friction nearly as much as you are in atmosphere.

Plus no matter how aerodynamic you are you are going to have friction in an atmosphere. Which is why you also have the added expense of heat shielding on space ships that enter the atmosphere (IE the Space Shuttle). I am not sure of the exact speeds the space shuttle re-enters the atmosphere at, I'm pretty sure it is significantly less than MACH-10. So you can very realistically have a fast space ship need to go slow when it enters and is within a planetary atmosphere similiar to earth (IE friction occurs).

Plus you can have star drives that only operate safely when free of planetary gravity wells. The more effect the local gravity well has on your ship the more likely you are to have a failure, probably one that is catastrophic.

So only "conventional" thrust engines can work within a given atmosphere.

Good enough?

 

[ThirdWizard]

Ever seen Cowboy Bebop? Big rings orbiting planets that a ship can fly through which take the ship to another ring somewhere else in the solar system. Kind of like some of the Stargates in Stargate: Atlantis, only much larger. That way they can go to various places in the solar system, but they can't leave the solar system becuase there are no gate ending points out there.

 

[Cedric]

Insert technobabble here...

Example, describe this particular area of the universe as having odd gravitational wavefronts, that, if navigated with the proper ship design using a special Engine (come up with some name based on the scientists who discovered it in your world...like maybe a Feinstein-Ritter Drive) allow rapid transit in this localized area.

Unfortunately, the wave fronts have to be VERY carefully assessed, charted and explored before they can be used for travel. Only the necessary surveillance to navigate within this system has been completed.

*shrugs* Just a thought.

 

[Cheiromancer]

Make the system smaller; 2 LY across is *huge*. In our own solar system, for example, Pluto is only about 6 light hours away. If a ship took a month to get there it would take 121 years to cover a light year.

 

[Meloncov]

Do you want the trip to take a few weeks for the characters or for a stationary observer? The latter would require faster then light technology, but the former would only require the ship travel at around 99.9% of the speed of light.

 

[CRGreathouse]

Do you want the trip to take a few weeks for the characters or for a stationary observer? The latter would require faster then light technology, but the former would only require the ship travel at around 99.9% of the speed of light.

Of course, 99.9% of the speed of light would take perhaps 50 times the thrust that 0.5c would take...

 

[starwed]

Make the system smaller; 2 LY across is *huge*.

Seconded. Simply make the system smaller, and you won't have a problem. (And the only reason I can think of to make a system that huge in the first place would be to drastically restrict travel, which obviously isn't your intent. )

 

[ThirdWizard]

Make the system smaller; 2 LY across is *huge*. In our own solar system, for example, Pluto is only about 6 light hours away. If a ship took a month to get there it would take 121 years to cover a light year.

I third this. IIRC alpha centauri is something like 4.5 light years away.