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Nyarli 08-12-2011 12:50 PM

TL9 Spaceships
 
I am reading Starship books, and i have some questions about drives:
1) I have made some calculations, and it's looks like magsails are Just Better for interplanetary transportation inside of Solar system at TL9( without superscience) than everything else, especially if you don't want more than 10 systems dedicated to propulsion. Magsails are on par with reaction drives on AU1, and outperform then on AU2+ distances, which is quite important, if you plan to travel to Jupiter or Saturn. They are not the most expensive of all drives, they don't require fuel and their only drawback is inability to start from planet. Am i right, or i have missed something?
2)Related question: Which drives would you allow to be used in Earth atmosphere? It is obvious that Orion drive is off-limits, but what about other drives?

sir_pudding 08-12-2011 01:02 PM

Re: TL9 Spaceships
 
Quote:

Originally Posted by Nyarli (Post 1229884)
Am i right, or i have missed something?

Other options might be cheaper in some applications if you are more worried about expense over velocity, but otherwise they seem like a pretty good choice in real-life too.
Quote:

2)Related question: Which drives would you allow to be used in Earth atmosphere? It is obvious that Orion drive is off-limits, but what about other drives?
Would who allow? Me personally? A likely near-future Earth (with a still active anti-nuke contingent)? A hypothetical space-faring civilization that's less conservative?

johndallman 08-12-2011 01:08 PM

Re: TL9 Spaceships
 
Quote:

Originally Posted by Nyarli (Post 1229884)
2)Related question: Which drives would you allow to be used in Earth atmosphere? It is obvious that Orion drive is off-limits, but what about other drives?

Do you mean "Which drives do you believe are capable of functioning in Earth atmosphere?" or "Which drives would you, as a GM, have be legal to use in Earth's atmosphere?"

Nyarli 08-12-2011 01:22 PM

Re: TL9 Spaceships
 
I asked about legality( and yes it is future of our Earth, not abstract space-faring civilization) but I would be glad to hear if some drive s from Spaceships are unable to function in atmosphere, by your opinion.

sir_pudding 08-12-2011 01:32 PM

Re: TL9 Spaceships
 
Quote:

Originally Posted by Nyarli (Post 1229901)
I asked about legality( and yes it is future of our Earth, not abstract space-faring civilization)

Then any kind of nuclear or antimatter propulsion is almost certainly right out.

wellspring 08-12-2011 01:35 PM

Re: TL9 Spaceships
 
Quote:

Originally Posted by Nyarli (Post 1229884)
I am reading Starship books, and i have some questions about drives:
1) I have made some calculations, and it's looks like magsails are Just Better for interplanetary transportation inside of Solar system at TL9( without superscience) than everything else, especially if you don't want more than 10 systems dedicated to propulsion. Magsails are on par with reaction drives on AU1, and outperform then on AU2+ distances, which is quite important, if you plan to travel to Jupiter or Saturn. They are not the most expensive of all drives, they don't require fuel and their only drawback is inability to start from planet. Am i right, or i have missed something?
2)Related question: Which drives would you allow to be used in Earth atmosphere? It is obvious that Orion drive is off-limits, but what about other drives?

1) Some people have argued that Spaceships is a mite too generous with the capabilities of magsails-- mostly the fact that (at least the plasma version) does require some consumables, which can be treated effectively as propellant. Also, the mathematics of them is highly simplified, so some of the downsides are lost in translation to a gaming product. They're still very good. In the Transhuman Space setting, much of the old-generation (TL9) commerce was on sails.

Another downside is with their lack of thrust, which for combat purposes makes them less useful as a combat drive.

2) Depends on the setting. The fission air ram of THS definitely has slightly radioactive exhaust. I think the same might go for fission, fusion and antimatter drives (including if they use ram-rockets). Enough that it would be a problem? Well, not for one ship, but if a planet has a fair amount of commerce then it might add up. It's also a psychological issue for people scared of radiation (which really is obviously very legit with an Orion) even when it's minor. Finally, there's the Kzinti Lesson: any drive efficient and powerful enough to be interesting is devastating if weaponized.

In Transhuman Space, anti-nuke laws keep them on chemical and laser rockets... but it would be hard for me to believe that they don't have military ships (openly or as a secret program) in reserve with more powerful nuke engines (such as pulse drives, antimatter thermal, NTR, or even Orion) for when you need real heavy lift capability.

Me, personally, if I were GM I'd allow it in a game, certainly. Habitable planets like Earth, I can see would have strict laws against it (though national gov'ts are not above exempting themselves from regulations intended to keep the hoi polloi in line). For the rest of the solar system, I don't see why such laws would exist. And in settings where you're flitting around uncharted space, why not use shuttles with some muscles? (The ram-rocket feature is especially useful here, since you can launch a shuttle, aerobrake on the way in, fly around exploring without burning propellant, and so have a mostly-full tank to return to the mother ship when you're done.)

sir_pudding 08-12-2011 01:39 PM

Re: TL9 Spaceships
 
Quote:

Originally Posted by wellspring (Post 1229907)
1)
2) Depends on the setting. The fission air ram of THS definitely has slightly radioactive exhaust. I think the same might go for fission, fusion and antimatter drives (including if they use ram-rockets). Enough that it would be a problem? Well, not for one ship, but if a planet has a fair amount of commerce then it might add up. It's also a psychological issue for people scared of radiation (which really is obviously very legit with an Orion) even when it's minor.

The big block to all nuclear and antimatter drives seems to be with accidental explosions and crashes rather than exhaust (since quite a few designs can have repetitively benign exhaust). I think you would need to have massive global political change to remove this.

wellspring 08-12-2011 01:41 PM

Re: TL9 Spaceships
 
Quote:

Originally Posted by sir_pudding (Post 1229910)
The big block to all nuclear and antimatter drives seems to be with accidental explosions and crashes rather than exhaust (since quite a few designs can have repetitively benign exhaust). I think you would need to have massive global political change to remove this.

Good point, though with a powerful enough reaction drive, global political change is surprisingly easy to accomplish!

sir_pudding 08-12-2011 01:44 PM

Re: TL9 Spaceships
 
Quote:

Originally Posted by wellspring (Post 1229911)
Good point, though with a powerful enough reaction drive, global political change is surprisingly easy to accomplish!

Yeah, but then we are back to the "abstract space-faring civilization" that the OP isn't asking about. The political status quo of Earth as it is simply doesn't care about space travel and is pathologically afraid of nuclear reactors.

wellspring 08-12-2011 01:47 PM

Re: TL9 Spaceships
 
Quote:

Originally Posted by sir_pudding (Post 1229912)
Yeah, but then we are back to the "abstract space-faring civilization" that the OP isn't asking about. The political status quo of Earth as it is simply doesn't care about space travel and is pathologically afraid of nuclear reactors.

That was meant as a quip. With a sufficiently powerful reaction drive, you can just hold the earth hostage and crown yourself Emperor Pudding I, then make whatever rules you want. Though I suppose a Pudding Regime would want to consolidate its position by immediately outlawing good reaction drives. So the point stands.


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