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Severe Misbalancing of engines?


ChronicSilence

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Just looking at some stats here:

- LV-T30 LFE

thrust: 200

burn rate: 8

- Toroidal Aerospike Rocket

thrust: 225

burn rate: 7.6

Am I missing something? The new rocket engine burns less fuel for more thrust. Neither engine requires atmosphere. Should I change every rocket engine on all my designs to this new one, and never use liquid fuel engines anymore?

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I don\'t understand how the standard fuel tank holds 3x as much as the medium sized fuselage, while the fuselage is easily twice as large.

Energy density. Rocket fuel has much more energy stored within it, and that extra energy is expressed when burned. At this time, the game makes no distinction between jet fuel and rocket propellant, so I\'d recommend building with the plane parts anyway to practice 'proper' design.

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Just looking at some stats here:

- LV-T30 LFE

thrust: 200

burn rate: 8

- Toroidal Aerospike Rocket

thrust: 225

burn rate: 7.6

Am I missing something? The new rocket engine burns less fuel for more thrust. Neither engine requires atmosphere. Should I change every rocket engine on all my designs to this new one, and never use liquid fuel engines anymore?

You can land on the liquid fuel engines, but you cant on the aerospike.... At least that I know of.

Also the aerospike is 2.5 mass rather then 2 mass for the LFE, that can make a large difference depending on the design.

I would say it might be more efficient to use the aerospikes on outer stages and the LFE on inner stages.

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You must remember that the resource system is placeholder, moreso than ever in 0.15; Eventually, those rocket tanks will be holding not only the fuel but the oxidizer, while the plane fuselages will be holding fuel only (for the most part, if its an actual SPACEplane it will need oxidizer too for the 'space' part)

And the weirdness of the aerospike is known. :)

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I\'m confused by those burn rates, as I can watch a standard tank being emptied like time warp was on with the Aerospike engine. I question whether it is really that effective an engine considering its fuel consumption rate.

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Originally I was totally for complete separation of rocket vs jet fuel but after thinking about the problem I had a change of heart.

See the best example for this is Skylon and its SABRE air breathing rocket engine. This engine can work both as a ramjet in atmosphere as well as a conventional bipropellant rocket engine using onboard liquid oxygen once there\'s no air. When Reaction Engines Limited or anyone else for that matter go build a spaceplane they\'re not going to go 'hey, let\'s put some jet engines on the plane that use kerosene and then add a rocket engine running on LOX/LH2 for final orbital burn' and end up carrying three different kind of liquid on the plane. They\'re going to get their engines to run off the same fuel plus some oxidizer for the rocket.

So with a splaceplane it\'s not a question of 'how much jet fuel vs how much rocket fuel to carry' but rather 'what\'s the ratio between fuel and oxidizer' that the plane will carry given a fixed flight profile. So instead of thinking we\'re adding rocket fuel and jet fuel to our splaceplanes think of as adding just 'tankage' to the plane and the little Kerbal engineers will work out the exact details on the fuel vs oxidizer ratio for that tankage space. It\'s only fair since we have no precise control over this ratio ourselves.

You can land on the liquid fuel engines, but you cant on the aerospike.... At least that I know of.

Think again:

25s8qok.jpg

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From the new plugin dev docs, I whould say that the plane can store a bit of KerbinAthmosphere (yes that\'s a fuel type used by Mu! Might change until .16 though), but it whould need intakes (maybe also cockpit/engine-integrated ones) to run for a long time.

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Also the aerospike is 2.5 mass rather then 2 mass for the LFE, that can make a large difference depending on the design.

- LV-T30 LFE

thrust: 200

burn rate: 8

mass : 2

Thrust to weight ratio: 100

- Toroidal Aerospike Rocket

thrust: 225

burn rate: 7.6 - Burn rate is 95% of the LV-T30

mass : 2.5 - 25% heavier

Thrust to weight ratio: 90 - 10 less TWR

Though the burn rate is indeed 5% lower. You\'ll note that the thrust to weight ratio is 90 on the aerospike. Even though its more efficient, its also 25% heavier then the other engine.

They\'re just different engines, and ideally the aerospike would be altitude compensating. The aerospike engine is a rocket engine, not an air breathing one in this case. So they\'re actually balanced, you could argue perhaps the LV-T30 is the overpowered engine if anything.

Regardless, there will be parts that are just better then the others. (this is the case in real life as well) In the full game they\'ll be limited by things like, cost, supply and technology level. But right now we have a sandbox environment with no costs or basis. Its sort of a moot point to argue over the engines being overpowered or not :)

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