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Old 01-27-2022, 10:05 PM   #1
Fred Brackin
 
Join Date: Aug 2007
Default Wrestling with starships bought as allies

I've starting mapping out how to do starships that are Allies and basically bought as Characters with Powers.

The FTL looks like the place to start and is probably the least detailed feature of the example bioship in Bio-tech.

So looking at Warp first with the HyperJump Limitation, specifically the -25% for 1 LY per Day version. That's going to be somewhat slow in an astronomically realistic universe but altering that parameter is as simple as buying Enhanced Move (Hyperdrive) for 20 pts per level. I've never seen anyone else do this but as a GM I'd allow it.

So what are the range penalties we're going to be looking at? Expanding the table in the Warp rules text gives us -19 for c. 32 LY which is probably long enough to zig-zag wherever you need to go.

That of course is if you can see your target. So we need to figure out how far away you can see a star. Sol is +55 SM for width with another +2 for being spherical. It's in plain sight for +10 to that and Spaceships gives another +24 for being silhouetted the blackness of space. Finally the Sun is at least as bright as a Fusion Rocket for another +8.

That's a final +99 which should be equal to a range of ......eh, I'm getting 5 LY. Somebody please check my math.

We can collect more bonuses for the instruments on the ship (bought as Telescopic vision) and probably adequately see any star within our hyperjump range. Empty patches of vaccum not so much.

We can ahndle the warp penalties by buying up Navigation(Hyperspace) Skill and putting Reliable on the basic Warp Power and taking some extra time. I know about the usefulness of spending FP and the munchkiness of buying lots of FP for a Warper but I want the default to be a machine without FP.

Of course we don't want to absolutely jump into the target star but the Hyperjump Limitation has the convenient feature of it not working in atmosphere and stars have "atmospheres" at least as astronomers define these things.

Multiple sources you can find will tell you that the corona is the upper atmosphere of our Sun are somewhat vague on where the limit of the corona is. However, the Parker Solar Probe is 6 million kilometers fro the photosphere and considered to be within the corona. It has sunshield that has to deal with 1300 degree F temps but the number outside will be lower than that and probably within the capability of a "normal" hull.

So you can leave one solar system and jump all the way to the corona of a target star. Then you turn around and jump from the edges of the corona to the edge of the atmosphere of your target planet.

I'm liking this because it does away with the need for normal space drives with "interesting" capabilities. If you let ships jump to the edge of the atmosphere you might not even need to buy the Space Flight Enhancement of your ship's Flight Power.

Maybe that's enough for a start. I'll try for more later.
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Old 01-28-2022, 05:12 AM   #2
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Default Re: Wrestling with starships bought as allies

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Originally Posted by Fred Brackin View Post
Of course we don't want to absolutely jump into the target star but the Hyperjump Limitation has the convenient feature of it not working in atmosphere and stars have "atmospheres" at least as astronomers define these things.
You could probably define a gravity-based limit instead as a special effect. On one hand, it could keep you farther out; on the other, it wouldn't let you come out closer even if you wanted to. If I recall correctly, tidal forces are approximately linear in diameter (for similar densities), which would make it easier to apply once you've decided on it.

Quote:
Multiple sources you can find will tell you that the corona is the upper atmosphere of our Sun are somewhat vague on where the limit of the corona is.
It moves around quite a bit, with flares and Coronal Mass Ejections and such. Using that as your limit will give you a lot more "weather" effects than is usual in (non-operatic) science fiction. I suppose this could be a feature, rather than a bug.

Quote:
So you can leave one solar system and jump all the way to the corona of a target star. Then you turn around and jump from the edges of the corona to the edge of the atmosphere of your target planet.
Two things:

First, you should consider the effect of large, bright stars on this kind of navigation. It may make more sense to jump to (e.g.) Rigel, 863 ly away, and then jump to your destination nearby, than try to "walk" there system by system. For the return trip, you could probably use Sirius. This gives your setting some topography, and offers a logical reason to name regions like "the Rigel sector."

Second, how are you planning to enter atmosphere and/or orbit at the destination planet? It seems to me that appearing at the edge of the sensible atmosphere (~ 100km above the surface on Earth) and diving straight in is not going to be survivable for most ship designs, Star Wars movies to the contrary not withstanding. Redirecting your real-space vector to achieve a reasonable entry or orbit is going to take some serious delta-V.
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Old 01-28-2022, 06:22 AM   #3
Fred Brackin
 
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Default Re: Wrestling with starships bought as allies

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Second, how are you planning to enter atmosphere and/or orbit at the destination planet? .
Probably float down on a superscience drive bought as Flight Power. That's the "natural" way to do it with a ship done as a character.

It doesn't have to be the actual atmosphere with planets. There's the magnetosphere and on the Sunward side there's a "bow shock" where the solar wind meets the magnetosphere about 10,000 miles out. That might give you similar numbers to your coronal limit physics-wise.

If you go with the magnetosphere or the bowshock you will need to buy the Space Flight Enhancement but the way the 4e rules for that work a superscience velocity-limited drive makes more sense ruleswise than trying to mimic physics.

You could have ships using a "space" drive limited to 1000 mph or so which would severely limit there potential as platforms for kinetic energy weapons. The "traditional" 1 G drive that could reach near c in a year would cost you 500 pts or more spent on Enhanced Move(Space) and present you with the familair accompanying problems.

Either of these hyper limits restricts where you can hyperjump to within a solar system. If the mainworld of the system was on the wrong side of the star you could probably do an intermediate jump to a gas giant but asteroids and many rocky worlds would be right out.

Going right into the edge of the atmosphere would help rationalize a setting that had "raids" like you see in Battletech. The 10,000 mile limit would give planetdwellers a short but probably manageable warning period and you might see some close range space combat. Although Spaceships has beam weapons that could start shooting at 10,000 miles or more.
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Old 01-28-2022, 06:52 AM   #4
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Default Re: Wrestling with starships bought as allies

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Originally Posted by Fred Brackin View Post
That's a final +99 which should be equal to a range of ......eh, I'm getting 5 LY. Somebody please check my math.
The math looks alright, but 5 LY is too short. A bit of searching online indicates Sol should be visible (albeit faintly) to most people at around 58 LY. Round that down to 50, and we see we're off by 6. That should be easy enough - a naked star with luminosity of 1 (relative to Sol) is at +14 (replacing the +8 for having a fusion reactor). Assuming luminosity and lux scale the same, then going off the Illumination Levels Table (from GURPS Powers: Enhanced Senses), that means every +4 SSR to luminosity (1, 5, 20, 100, etc) is +1, while every -4 SSR to luminosity (1, 0.2, 0.05, 0.01, etc) is -1.
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Old 01-28-2022, 07:11 AM   #5
Fred Brackin
 
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Default Re: Wrestling with starships bought as allies

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The math looks alright, is
I'm glad my math is alright but seeing the star was just something i was afraid would be a problem rules-wise. It was never going to be a problem with ship's instruments. Spaceships gives you (I think) Telescopic Vision equal to TL and lets you claim a time spent bonus too. I' really don't want to go off into the high weeds of the illumination rules.

Even if we did i think getting both the Size Modifier and a bonus for tolla luminosity might be double dipping. the SM bonus was already covering it being a _big_ fusion reactor. :)
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Old 01-28-2022, 07:22 AM   #6
Varyon
 
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Default Re: Wrestling with starships bought as allies

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Originally Posted by Fred Brackin View Post
I'm glad my math is alright but seeing the star was just something i was afraid would be a problem rules-wise. It was never going to be a problem with ship's instruments. Spaceships gives you (I think) Telescopic Vision equal to TL and lets you claim a time spent bonus too. I' really don't want to go off into the high weeds of the illumination rules.

Even if we did i think getting both the Size Modifier and a bonus for tolla luminosity might be double dipping. the SM bonus was already covering it being a _big_ fusion reactor. :)
Giving it another look, it appears +99 is closer to 7 LY than 5 - +99 would be 7x10^16 yards, which is 6.77 LY, which I'd probably just treat as 7. So that implies we need a +5... but that would be for an average person to have a 50% chance to see it immediately when looking in its direction. Being able to see it eventually corresponding to a roll of 5 or less (rather than 10 or less) doesn't seem outlandish, so I think we don't need any further adjustment after all.
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Old 01-28-2022, 07:26 AM   #7
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Default Re: Wrestling with starships bought as allies

Why is one light-year per day "slow"? At that speed, you can travel 365 light-years in a year, which is a sphere with a volume of just under 204 million cubic light-years. Wikipedia says our local neighborhood had one star per 2360 cubic light-years, so that's 86,000 stars. Isn't that enough for a reasonable campaign?

A speed of one light-year per day is 365c, which in Start Trek terms is Warp Factor 7.15. That was usually fast enough for Kirk and Spock . . .
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Old 01-28-2022, 07:41 AM   #8
Fred Brackin
 
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Default Re: Wrestling with starships bought as allies

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Why is one light-year per day "slow"? . .
Only because I've seen estimates that put Earth-like planets 100-200 LY apart and if you send PCs on trips that long they're going to start filling out time use sheets for studying new Skills.

An average trip length of 1 week might be about the only way I wanted to emulate Traveller but it's a decent interval for most space adventure games.
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Old 01-28-2022, 08:34 AM   #9
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Default Re: Wrestling with starships bought as allies

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Originally Posted by Fred Brackin View Post
Only because I've seen estimates that put Earth-like planets 100-200 LY apart and if you send PCs on trips that long they're going to start filling out time use sheets for studying new Skills.

An average trip length of 1 week might be about the only way I wanted to emulate Traveller but it's a decent interval for most space adventure games.
Even with stars that far apart, a crude estimate would have ~60 Earthlike planets in that sphere one year in radius (it could be as few as 25 or as many as 200). That ought to be enough for a diverse campaign setting, perhaps with several sapient races. No GM is going to make up 86,000 star systems.

And why shouldn't PCs take the time to learn new skills? Though I would use the monthly study rolls mechanic, myself. It isn't as if you had to roleplay every lesson along the way. Treat it like a Pendragon campaign where a typical turn is three months, and you play out the visits to new planets in detail and skim over the travel time.
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Old 01-28-2022, 08:42 AM   #10
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Default Re: Wrestling with starships bought as allies

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Originally Posted by Varyon View Post
Giving it another look, it appears +99 is closer to 7 LY than 5 - +99 would be 7x10^16 yards, which is 6.77 LY, which I'd probably just treat as 7.
Interestingly, you can easily create a rough conversion chart for the SSR table (multiplication becomes addition on a log-based scale).

Look up the measure as though it were yards and add:
Kilometers: 18
Miles: 20
Light-seconds: 51
AU: 67
Light-years: 96
Parsecs: 99
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