Autorefueler and ditching/reducing separate fuel tank

[DraQ]

Here's how:

• Leave 1-2t "buffer" tank (more if the ship has a lot of volume unsuitable for cargo - like wings), merge freed space with cargo bay
• Equip all ships with auto-refueling routine
• Read delta-v based on all propellant - cargo bay AND tank for both autopilot and readout purposes

Here's why:

• Would allow weighing propellant against equipment when fitting the ship for different purposes
• Would allow dumping excess propellant in emergency (like take-offs from high gravity planets or combat scenarios)
• Would allow autopilot to use more than just twice default tank delta-v when carrying enough propellant
• Would free player from sitting in cargo bay and manually refueling when going somewhere with extra propellant

Here's some additional features that would be nice:

• Jettisoning propellant should make it vent instead of dropping containers - you don't pick up containers when you scoop, and yet you can drop them?
• It would be nice to have an option to manually allocate propellant reserve autopilot should leave, or at least lock down automatic refueling in case you want to do something more complex than going from A to B and docking to refuel.

[luovahulluus]

Also: It costs me $1 to land and refuel 30t of the internal tank. It costs me $30 to put 30t of fuel into the cargo bay.

I was recently floating in an uninhabited system with 1t of fuel in my cargo bay. Next system was 2t of fuel away. It would have been nice to use one additional tonne of the fuel I had in the internal tank...

I agree, we should have all our fuel in the cargo bay. This would give us the choice to transport alot of cargo slowly or alittle of it quickly.

[lwho]

Also: It costs me $1 to land and refuel 30t of the internal tank. It costs me $30 to put 30t of fuel into the cargo bay.

Yes, I always thought the docking fee should be "price of fuel + constant fee".

I was recently floating in an uninhabited system with 1t of fuel in my cargo bay. Next system was 2t of fuel away. It would have been nice to use one additional tonne of the fuel I had in the internal tank...

I've been arguing for a kind of "unfuel" button several times (the last time in #2853, when another button was just added at the same place). Others seemed to assume that my argument "it is annoying to strand in an uninhabited system with a tank full of hydrogen you can't reach" is only theoretical. Maybe create a feature request in github?

Leave 1-2t "buffer" tank (more if the ship has a lot of volume unsuitable for cargo - like wings), merge freed space with cargo bay

I agree, we should have all our fuel in the cargo bay. This would give us the choice to transport alot of cargo slowly or alittle of it quickly.

I don't think, that would be a good idea. The autopilot can not know, how much hydrogen you need left for hyperjumps. So, that way you could end up consuming all your (hyperjump) fuel by accident. I would prefer separate "tanks" which you can freely´move hydrogen between.

[DraQ]

Leave 1-2t "buffer" tank (more if the ship has a lot of volume unsuitable for cargo - like wings), merge freed space with cargo bay

I agree, we should have all our fuel in the cargo bay. This would give us the choice to transport alot of cargo slowly or alittle of it quickly.

I don't think, that would be a good idea. The autopilot can not know, how much hydrogen you need left for hyperjumps. So, that way you could end up consuming all your (hyperjump) fuel by accident.

There are ways around it:

• Allocate fuel reserve functionality that'd set the minimum amount of hydrogen in cargo bay for the autorefueler to function - could be set to the cost of jump to selected system by default.
• Separating fusion/jump fuel from remass - for example making it helium-3 that could be scooped along with hydrogen from gas giants.
• Making hydrogen into two technically separate cargo items - say "hydrogen" and hydrogen (propellant)", one used for jumps, the other for reaction drive - and letting player convert their fuel between those two flavours at will.

I would prefer separate "tanks" which you can freely´move hydrogen between.

Even with ability to move fuel between them separate tanks don't allow for making extra equipment/cargo space at the cost of fuel, nor do they let the autopilot know it has increased delta-v budget at its disposal.
Fuel in cargo bay, with 1t buffer tank representing partially spent ton is better, far more flexible option.

[luovahulluus]

I agree, we should have all our fuel in the cargo bay. This would give us the choice to transport alot of cargo slowly or alittle of it quickly.

I don't think, that would be a good idea. The autopilot can not know, how much hydrogen you need left for hyperjumps. So, that way you could end up consuming all your (hyperjump) fuel by accident.

This is how I use fuel: launch and jump immediately after => Jump again if necessary => fly to the next spaceport and refuel.
You use your hyperjump fuel before normal-space fuel. Apart from mining, why would you want to go somewhere you can't refuel at?
I suggest there is an adjustable amount of fuel for the auto-refuel routine so that you would have the right amount of fuel for the kind of jobs you are doing. There also should be a post-autopilot reserve that you can adjust depending whether you can refuel at your target or not.

Even with ability to move fuel between them separate tanks don't allow for making extra equipment/cargo space at the cost of fuel, nor do they let the autopilot know it has increased delta-v budget at its disposal. Fuel in cargo bay, with 1t buffer tank representing partially spent ton is better, far more flexible option.

Can we make the autopilot estimate the usage of fuel and changing mass of the craft, or would it just calculate new trajectory after every ton of fuel used?

[DraQ]

This is how I use fuel: launch and jump immediately after => Jump again if necessary => fly to the next spaceport and refuel.
You use your hyperjump fuel before normal-space fuel. Apart from mining, why would you want to go somewhere you can't refuel at?

In the current game or at all?

Because I can envision plenty mission profiles that would require multiple transits - with or without jumps - with no refueling opportunity inbetween.
Hell, take something as simple as recon/bombardment in original Frontier.

Still, any of the solutions mentioned should take care of the problem, and It's not like current solution with separate fuel tank allows for fuel rationing when flying around on autopilot.

Can we make the autopilot estimate the usage of fuel and changing mass of the craft, or would it just calculate new trajectory after every ton of fuel used?

I'm not privy to the game's inner workings - at least not yet.
Though, TBH, I don't see why the autopilot wouldn't work just as well as it does now if it was fed buffer+allocated fuel total instead of just tank info.