Matching thrust between different engine types

[ArmchairGravy]

I've assembled a ship in orbit that has a tug using 4 LV-N's up front, and a main body that has a mainsail on it. Now while I could drop the mainsail, it has an almost full orange tank. If the LV-N has 60 thrust, and the mainsail has 1500, would their outputs match if I limit the mainsail to 4% thrust (60/1500), or would it be 16% as there are 4 of them? Or would either way work since at 4% would act as another LV-N, and 16% would act as the sum of the four? Or am I on the wrong track entirely?

Edited December 26, 2013 by ArmchairGravy

[How2FoldSoup]

the 16% would work. However you should just drop the mainsail...In orbit the fuel efficiency of the LV-N is far greater and will get you a lot farther than the mainsail will. Remember, in space you can push anything but you must choose between efficiency or speed. You will get a lot more dv out of the LV-Ns than the mainsail for sure. Ideally you'd only want to use the mainsail for lifting a payload and then jettison it otherwise its extra mass that you're stuck pulling around.

[ArmchairGravy]

OK, thanks for checking my thinking on this. I was planning on ditching it after I'd burnt all the fuel, but you're saying I'd be better off ditching as much weight as I could right off the bat, and let the LV-N's do their job.

[Andon]

OK, thanks for checking my thinking on this. I was planning on ditching it after I'd burnt all the fuel, but you're saying I'd be better off ditching as much weight as I could right off the bat, and let the LV-N's do their job.

REALLY depends with the fuel you have. Honestly, depending on the setup, I'd probably fill my other fuel tanks, then shut them from using any fuel and use the Mainsail for a burn or two before ditching it and the tank. I'm not one to waste fuel that's in orbit, though, and it IS best to ditch the mainsail if it'd be sucking off of the main craft's tanks.

[longhornchris]

If you have to drop the fuel with the mainsail it may be better overall to disable the mainsail, burn using only the LV-Ns, and ditch the engine and tanks once you've expended the fuel. Using the mainsail is a waste as its ISP isn't as good and you don't need the thrust

[SRV Ron]

If you have to drop the fuel with the mainsail it may be better overall to disable the mainsail, burn using only the LV-Ns, and ditch the engine and tanks once you've expended the fuel. Using the mainsail is a waste as its ISP isn't as good and you don't need the thrust

Similarly, if the Mainsail was needed to get into orbit, but left you with lots of fuel in the main tank, place a decoupler between it and the fuel tank to stage it. You will have to run a fuel line to the Mainsail.

This is a similar setup for my interplanetary asparagus with LV-N core. The outboard engines are staged just prior to reaching orbit.

[Spyritdragon]

Whatever engine you use, any fuel you drop is going to be a waste - whatever situation you're in that has an engine, you can always burn this engine to increase the entire craft's speed and getsome delta-V out of it. Personally, unless it hampered my rotation all too much or prevented me from docking/landing effectively, i'll always keep the tank with the fuel in it. This is, assuming everything is preformed in the vacuum of space.

My advice is to fill all tanks you're not going to drop, cut off fuel flow from any tanks but the orange one attached to the mainsail you're going to ditch - then, use either the LV-N's or the mainsail, depending on how much thrust you actually need (we have tweakables for this now ^-^) to empty this tank, then ditch it once its empty. You now have a fully-fueled craft with LV-N's on it, and no delta-V wasted.