On fuel, skimming GGs, and 1G drives...

[Supplement Four]

Skimming GG’s

I always interpreted the 8-hour operation to mean that the ship settled into the lowest possible orbit around the GG, where there existed a very small concentration of hydrogen gas. The ship spends 8 hours in this relatively safe orbit sucking up the raw fuel it needs, then accelerates out of orbit once the tanks are full. This seems much more tame than the suggested repetitive “dive-bombing” of the upper atmosphere.

But...but...the dive bombing is so much more coooooollll for a game!

Describe it to your players--you dive deep into the outer atmo of the behemoth. Magnitomiter is off the charts. Lightning crashes in the distance, electrifying the clouds. Pockets of methane and hydrogen and other gasses rock the ship as your vessel rockets through them...

I think it's just fun.

On the big ships, the fuel jockeys have this mistique about them. They're regarded kinda like the test pilots. Lean and mean and livin' on the edge.

They get all the women too.

1G Maneuver Drives on Size 9+ Worlds

Why not take the middle ground?

I kinda like how CT keeps 1G vessels away from Size 9+ worlds without good orbital starports.

It really adds to the "reading of a subsector" process the GM goes through when setting up his campaign.

It adds islands and vortexes and whirlpools to the ocean of space.

LBB2/TTB fuel purification

While it doesn’t explicitly state this that I’m aware of...

Actually, in the other thread you mention, we did find where Book 2 specifically stated that ships under LBB2 design do not have fuel purification.

I'd have to find it again, though (or just check that other thread).

 

[Supplement Four]

So that infers that 0.5 atmospheres is the max that most ships will go that do not have a 3G M-drive or greater. But what is the outermost level?

Simple. Just use the world templates chart in TTB. That'll show you, at-a-glance, how far an M-Drive can take a ship into a world's atmo and still reach escape velocity.

 

[Foxroe]

But...but...the dive bombing is so much more coooooollll for a game!

Describe it to your players--you dive deep into the outer atmo of the behemoth. Magnitomiter is off the charts. Lightning crashes in the distance, electrifying the clouds. Pockets of methane and hydrogen and other gasses rock the ship as your vessel rockets through them...

I think it's just fun.

On the big ships, the fuel jockeys have this mistique about them. They're regarded kinda like the test pilots. Lean and mean and livin' on the edge.

They get all the women too.

LMAO! Too true! I made this statement before Mike was so kind as to provide the link to the GG article on the Freelance Traveller site. I will definitely have to spice my games up with this!

Looking forward to the next "Gas Giant Girls Gone Wild" installment...

-Fox

 

[Foxroe]

I kinda like how CT keeps 1G vessels away from Size 9+ worlds without good orbital starports.

It really adds to the "reading of a subsector" process the GM goes through when setting up his campaign.

It adds islands and vortexes and whirlpools to the ocean of space.

Not that I ever had a problem with the low-G ships and higher-G worlds "rule" (it does add flavor), but I always had a hard time wrapping my head around why grav vehicles didn't have the same limitations as ships. Is it a simple matter of F=ma? In other words, is it that the mass of these vehicles is sufficiently small enough that that can muster up enough force to overcome the negative acceleration due to gravity, but starships/small-craft cannot? How does everyone else handle this?

-Fox

 

[Supplement Four]

Not that I ever had a problem with the low-G ships and higher-G worlds "rule" (it does add flavor), but I always had a hard time wrapping my head around why grav vehicles didn't have the same limitations as ships.

You're confusing the force required to move and the force required to achieve escape velocity.

Two different things.

EDIT: Check out the G drive units in Striker. There are several. If you design a vehicle with one that produces less than 1 G of thrust, your vehicle will move but not achieve escape velocity.

 

[Icosahedron]

I thought grav vehicles did have the same limitations - where does it say otherwise?

If they don't, maybe they work via a different thrust mechanism?
I've never really figured out a coherent and internally consistent idea of how grav thrusters and deckplates work.

However, I tend to keep grav vehicles sub-orbital anyway, unless they have spacecraft-grade armour.

That's a great description of GG atmospheres. Mentally noted away.

 

[Ishmael]

IMTU, grav tech power requirements are based on potential energy. As star/spaceships are are armored like an Abrams tank and grav vehicles like a volkswagen, mass is the cause of different grav vehicles and space vehicles. Also, as altitude increases, so does power needed, thus no vehicle can operate at too high altitude; spaceships need other thrust agencies to truly leave a world. I use Heplar myself )

I also use aero drag to figure speed in an atmosphere, whether GG or planetary. Top speed possible is where thrust equals drag. Aerodynamic heating is blackbody energy absorbed at about 2%* of energy needed to overcome drag.

< yeah, I know...over-the-top gearhead crap..... but I have to play 'solo' so I do a lot of things like that which would be bad if done around a coffee table with people >

* based on something I read about how much energy goes toward aero-heating in the space shuttle.