Clarity request: Gravitic Drive Ships

[pendragonman]

I am trying to design ships with Gravitic Drives for Maneuver and NAFAL for between the stars action.

A) Do I need both to travel the planetary system? Can Nafal give me the thrust required to go from, say, Earth to Jupiter or do I need the Gravitic drive for that?

2) Do I need a separate power plant for Operations in ships (boats) that operate the Gravitic drive only? How about one with NAFAL?

 

[Magnus von Thornwood]

Yikes!

I am trying to design ships with Gravitic Drives for Maneuver and NAFAL for between the stars action.

A) Do I need both to travel the planetary system? Can Nafal give me the thrust required to go from, say, Earth to Jupiter or do I need the Gravitic drive for that?

2) Do I need a separate power plant for Operations in ships (boats) that operate the Gravitic drive only? How about one with NAFAL?

Congrats, you hit an area where I am weak in ACS. Still, I am a Naval Arcitect so I will give it the old college try.

A) As to the use of NAFAL Drives in-system, yeah they can be used but they are still slow to get moving and a Manuever Drive would be quicker. Gravitic Drive remember is a less powerful version of the Manuever Drive, but more powerful than Lifters and as such aren't the greatest for interplanetary travel.

2) Yes. All Drives require some form of Fuel, may not be a lot, but it needs some.

 

[whulorigan]

I am trying to design ships with Gravitic Drives for Maneuver and NAFAL for between the stars action.

A) Do I need both to travel the planetary system? Can Nafal give me the thrust required to go from, say, Earth to Jupiter or do I need the Gravitic drive for that?

2) Do I need a separate power plant for Operations in ships (boats) that operate the Gravitic drive only? How about one with NAFAL?

A) The NAFAL drive is apparently a highly focused G-Drive, and can only propel directly toward and away from a gravitating body (i.e. no lateral motion). In theory you could use an N-Drive in-system, but I think the maneuverability would be severely hampered. So you would probably want a separate maneuvering drive of some sort (M-Drive, G-Drive, or some type of reaction-mass R-Drive (you are on your own with the last one)).

B) I gather that the G-Drive is self-powered, but does not provide power for other systems. But if you are not using an FTL-Drive, you could in theory power the boat from Cold Fusion/Fusion-Plus modules. Power Plants (A, P, U) generally exist to support heavy power consumption, like M-Drives, N-Drives, and the various FTL-Drives.

The N-Drive (NAFAL) does require an independent supporting power plant (A, U, P).


See T5, p.339, 376-378.

 

[pendragonman]

A) The NAFAL drive is apparently a highly focused G-Drive, and can only propel directly toward and away from a gravitating body (i.e. no lateral motion). In theory you could use an N-Drive in-system, but I think the maneuverability would be severely hampered. So you would probably want a separate maneuvering drive of some sort (M-Drive, G-Drive, or some type of reaction-mass R-Drive (you are on your own with the last one)).

B) I gather that the G-Drive is self-powered, but does not provide power for other systems. But if you are not using an FTL-Drive, you could in theory power the boat from Cold Fusion/Fusion-Plus modules. Power Plants (A, P, U) generally exist to support heavy power consumption, like M-Drives, N-Drives, and the various FTL-Drives.

The N-Drive (NAFAL) does require an independent supporting power plant (A, U, P).


See T5, p.339, 376-378.

Yes, G-drives have their own internal fusion plant but don't offer extra power for operations (computer, LS, etc.) Fuel-wise this means that at annual maintenance a new set of pellets are put in.

The idea is an ATU where M and J drives do not exist, but (right out of Starfire) warp points link certain systems for FTL. So to get from the planet at Orbit Ay to the GG at Orbit Em is to build up your vector until the 10D limit, drift under that vector to your target, then decelerate when you reach the 10D limit of your target. I aim to have either peroxide reaction modules or use the 1% efficiency of the G-drive for slight adjustments in vector along the way.

For travel between stars there is the Worm Holes (warp points, both open and closed) for FTL, but they may not go directly to where you want and NAFAL for heading directly to your target.

Either in system or NAFAL requires a lot of dead time, so accommodations are low births for the majority of the time, with wake up by robots for emergencies or arrival maneuvering and spacer niches when they are awake.

Hence my questions about external power needs.

Haven't looked at N drives. (unless that is another name for NAFAL)

 

[whulorigan]

Haven't looked at N drives. (unless that is another name for NAFAL)

N-Drive = NAFAL

 

[robject]

I think y'all got it, but just to pile on...

Gravitic drives are sealed and run for a year before requiring maintenance. You do not need Engineers to tend them. They work within 10 Diameters of a gravity source. So to use them insystem, you'll have to coast for most of the distance. Accelerating for 20 D, from one end of an Earth-sized world through the other end and onwards, gets you 0.2 AU per week -- a crawl. And if your target world is smaller than your origination world, you can't accelerate for the full 20 D!

With NAFAL you have a different mechanic: you wait until your target world insystem is in conjunction WITHIN YOUR TRAVEL WINDOW, and then accelerate straight out. NAFAL-1 is 0.1G equivalent, so if you're travelling 10 AU outwards, you're looking at a 28 day trip, and you can't decelerate. Plus the wait for the proper launch window, which I suppose happens very approximately yearly (slightly longer actually, but *meh*).

NAFAL can run off of a Fission or Antimatter power plant, so it doesn't necessarily require fuel either.

And as always, higher drive ratings make everything better.

 

[pendragonman]

I think y'all got it, but just to pile on...

Gravitic drives are sealed and run for a year before requiring maintenance. You do not need Engineers to tend them. They work within 10 Diameters of a gravity source. So to use them insystem, you'll have to coast for most of the distance. Accelerating for 20 D, from one end of an Earth-sized world through the other end and onwards, gets you 0.2 AU per week -- a crawl. And if your target world is smaller than your origination world, you can't accelerate for the full 20 D!

With NAFAL you have a different mechanic: you wait until your target world insystem is in conjunction WITHIN YOUR TRAVEL WINDOW, and then accelerate straight out. NAFAL-1 is 0.1G equivalent, so if you're travelling 10 AU outwards, you're looking at a 28 day trip, and you can't decelerate. Plus the wait for the proper launch window, which I suppose happens very approximately yearly (slightly longer actually, but *meh*).

NAFAL can run off of a Fission or Antimatter power plant, so it doesn't necessarily require fuel either.

And as always, higher drive ratings make everything better.

10 AU, so still in system. and 28 days means you aren't even to max NAFAL speed yet. That takes 51 weeks...

In this ATU I am using T5 ship design and World/system/subsector generation, but Mongoose for chargen and equipment because my players can get Mongoose stuff at Our Friendly Game Shoppe. The Great Cabal needs to try to get Marc to speed up corrections and get at least a starter box into the shops.

 

[Magnus von Thornwood]

That's Fuel!

/snippity-snip/

NAFAL can run off of a Fission or Antimatter power plant, so it doesn't necessarily require fuel either.

And as always, higher drive ratings make everything better.

Dude, maybe, and it is a loose maybe since you still need a supply of fissionables to replace depleted rods, but anti-matter the sure as Space Hells (or Misjump :devil qualifies as Fuel. For crying out loud, man AM Slugs are listed in the Fuel box. Geez, My Lord Patron you are making us look bad.

 

[pendragonman]

Ok, Just to be sure...

Can N drives be used in system. Unless I am missing something the RAW seems to say NAFAL drives are only for interstellar drives (turn it on, accelerate for 51 weeks, coast to next parsec) , but it also says that it is a highly efficient G drive.

So, if I have an N drive, do I also need some sort of Maneuver drive?

 

[Reban]

I think the intent is that the NAFAL Drive is for making that long interstellar voyage and there should be some other means of propulsion for maneuvering in system.

But having said that theres nothing specific disqualifying you from using it as an M-Drive or G-Drive substitute.

The big difference is the potential.

G-Drives and M-Drives have a potential of 1 to 9Gs

N-Drives have just one tenth the potential of 0.1 to 0.9Gs


You can also think of it this way, an N-Drive is a slow but very long endurance version of the other gravity drives.

Using an N-Drive might turn out to be like building your ship like Aesop's tortoise; slow and steady will win the race, and get you there in the end.

 

[robject]

Dude, maybe, and it is a loose maybe since you still need a supply of fissionables to replace depleted rods, but anti-matter the sure as Space Hells (or Misjump :devil qualifies as Fuel. For crying out loud, man AM Slugs are listed in the Fuel box. Geez, My Lord Patron you are making us look bad.

Not in the sense of "oh my gosh, we're almost out of fuel!" kind of fuel, though. Both Fission and Antimatter work for a year on one load. A year of operations is, well, long enough in my book to behave less as fuel and more like "maintenance". And, compared to Power Plant fuel, well, those things create a completely different paradigm.

 

[robject]

Can N drives be used in system. Unless I am missing something the RAW seems to say NAFAL drives are only for interstellar drives (turn it on, accelerate for 51 weeks, coast to next parsec) , but it also says that it is a highly efficient G drive.

So, if I have an N drive, do I also need some sort of Maneuver drive?

The problem with NAFAL is that it pushes towards, or away from, the primary. So yes, you could use NAFAL, but your orbits will have to be timed to take conjunction into account, and you can't (for example) accelerate in just any old direction.

 

[pendragonman]

The problem with NAFAL is that it pushes towards, or away from, the primary. So yes, you could use NAFAL, but your orbits will have to be timed to take conjunction into account, and you can't (for example) accelerate in just any old direction.

An excellent point. So yes, a separate M drive of some nature is necessary. So we come back to the old paradigm issue of balancing the drives for the space available.