Squad Should Re-Balance the Poodle Engine

[Steambirds]

I've noticed one thing in all of my years of playing Kerbal Space Program ever since the Poodle Engine came about: It is really useless. It's meagre thrust coupled with its high weight means that it simply is not powerful enough to get the job done. I seriously think Squad should lower its weight, increase its thrust, or mess with it's Delta-V, because it's pretty much useless for anything but landers.

[MartGonzo]

You leave my beloved poodle engine alone!

I use it a lot, especially a tweakscaled 1.25m version instead of the Lv-909

[pellinor]

As far as I know tweakScale still messes up the TWR of engines. As a default, part mass has a scaleExponent of 3 and thrust has 2. The consequence is that scaling to half size will double the TWR of an engine. This bug makes shrinked engines extremely powerful and enlarged ones pretty much unusable. So your 1.25m poodle is probably more powerful than the boost Steambirds asks for.

Edited November 22, 2014 by pellinor

[MartGonzo]

As far as I know tweakScale still messes up the TWR of engines. As a default, part mass has a scaleExponent of 3 and thrust has 2. The consequence is that scaling to half size will double the TWR of an engine. This bug makes shrinked engines extremely powerful and enlarged ones pretty much unusable. So your 1.25m poodle is probably more powerful than the boost Steambirds asks for.

Thanks I must admit, I hadn't really thought about that, I just like the way it looks compared to the Lv-909

[Jouni]

The Poodle is quite useful after the rebalance in 0.24. It's a high-thrust vacuum engine that fits nicely in a 2.5 m stack, making it a good upper stage engine for most payloads.

[Slam_Jones]

While being one of my less-used engines, I still find it has a place as a circulizer stage for some of my heavy ships, and sometimes as a little extra push at launch (in conjunction with a giant Kerbo booster)

[Steambirds]

Maybe I design enormous rockets, but I find the Skipper engine far more versatile for an upper stage + orbiter engine for my payloads.

[hazarada]

The poodle and the lvl-909 are both useless in my book. The little extra vacuum LSP over higher t/w engines isn't worth their extra weight. I much prefer the rockomax 48-7s in landers due to its phenomenal t/w which generally gives it more dV despite having lower lsp. And then there's the weightless mono propellant engines and the overpowered KR-2l.. the engines are just way out of balance in general.

[Wanderfound]

The poodle and the lvl-909 are both useless in my book. The little extra vacuum LSP over higher t/w engines isn't worth their extra weight. I much prefer the rockomax 48-7s in landers due to its phenomenal t/w which generally gives it more dV despite having lower lsp. And then there's the weightless mono propellant engines and the overpowered KR-2l.. the engines are just way out of balance in general.

...which is why there is substantially balancing to come in .90 and beyond.

[steve_v]

'A reasonable engine for rough economic times" pretty much sums up my use for the poodle - disposable 2.5m upper stages.

Not sure I agree on the 909 though, it's pretty handy - especialy early in a career game.

[Bekiekutmoar]

Hail to the 48-7S engine indeed ... ! It even performs excellent on airless bodies with somewhat higher gravity (Vall/Moho)

[Jouni]

The poodle and the lvl-909 are both useless in my book. The little extra vacuum LSP over higher t/w engines isn't worth their extra weight. I much prefer the rockomax 48-7s in landers due to its phenomenal t/w which generally gives it more dV despite having lower lsp. And then there's the weightless mono propellant engines and the overpowered KR-2l.. the engines are just way out of balance in general.

Engine balance is a lot better than it used to be. There are five engines I can't find good use for, and for two of them it's only because of my design preferences:

• The LV-1 and the LV-1R are just too small for my taste.
  
• The Mark 55 is too inefficient to be used as a main engine, too weak for a booster engine, and too large for a lander engine or an orbital maneuvering engine.
  
• The LV-909 is useful in the early career mode, but the 48-7S replaces it in most uses almost immediately. Aesthetic preferences are pretty much the only reason to favor the LV-909 over the 48-7S, as the former fits better in an 1.25 m stack.
  
• The RT-10 is just too small and short-lived for anything but silly contraptions.
  

The rest of the engines are quite useful for one purpose or another. Here are my typical uses for them:

• The O-10 and the 24-77 are my standard orbital maneuvering engines. Sometimes I use them in landers as well. As small radial engines, it's easy to place them almost anywhere, and they're also quite powerful.
  
• The 48-7S is small, powerful, and quite efficient. It's the engine of choice for small landers, if ease of use is more important than maximal efficiency. Its main drawback is that it's a small inline engine: using more than one of them usually requires ugly hacks that unnecessarily increase the part count.
  
• The LV-T30 and the LV-T45 are general-purpose engines. I mostly use them in small launchers, with an LV-T45 in the lower stage and LV-T30s in the boosters. Their shape is a bit unwieldy for using them in space.
  
• The Aerospike is the right engine for one-kerbal Eve landers. It could be useful as a vacuum engine, but because there is no attachment node in the bottom, you usually need at least two of them, and you rarely need that much thrust in vacuum.
  
• The LV-N is the ultimate vacuum engine for large payloads and/or high delta-v requirements. Its much more efficient than any other engine using LF/O, and the TWR is high enough for landing on most bodies. The shape of the engine is very unwieldy, however, so you'll almost always need at least two of them.
  
• The Poodle is a good upper stage engine for a large range of common payloads. It's also useful as a transfer stage engine to Mun and Minmus, as well as for giving the initial boost for interplanetary transfers from low orbits. I don't use it in landers, because nuclear engines are almost always a better choice, if you need that much thrust.
  
• The Skipper is another general-purpose engine. I use it in the lower stages of small rockets, in the upper stages of larger rockets, and sometimes also for giving the initial boost for interplanetary transfers.
  
• The Mainsail has become a niche engine. I sometimes use it as a booster engine in medium rockets, where the higher thrust of the LFB is not as important as the higher Isp of the Mainsail. It might be a good engine for large Eve landers.
  
• The LFB is obviously a booster engine for uses, where raw power is more important than efficiency. As the 3.75 m engines are all too weak, I often use LFBs to allow these big rockets lift off with a useful amount of fuel.
  
• The KR-2L is yet another general-purpose engine that can be used when the Skipper becomes too weak.
  
• The KS-25x4 is the most powerful stock engine there is. It's useful for the lower stages and the boosters of large rockets.
  
• The two larger SRBs are obviously useful as boosters. In smaller rockets, I often adjust their thrust down to avoid the TWR dropping too low when the boosters burn out. In larger rockets, a bunch of SRBs can be useful for increasing the initial TWR a bit.
  
• The PB-ION is hard to use properly. It's very efficient, and even the TWR is high enough for landing on the Mun. With larger xenon containers, the ion engine would replace nuclear engines in transfer stages, but now its mostly useful for small ships.
  

Then there are the airbreathing engines. I don't use them, because they feel silly.

[Steambirds]

I love the LV-909, but then again most of my missions are Kerbin-bound because I always feel too lazy to mess around with launching huge stuff into space for a massive interplanetary vessel.

[Bill Phil]

My main Poodle complaint is the small TWR. But besides that it's great.

Personally I think that a new Poodle-Skipper interim with decent ISP and 3x the thrust of the Poodle, but at nearly twice the mass.

[Steambirds]

I think to re-balance the Poodle engine the ISP should be raised, making it a "poor man's LV-N".

[bv1]

I must admit that I don't really use the Poodle much. I'd say that its mass should be reduced to 1.65 in order for its TWR to be on par with the LV-T45.

[Jouni]

Why would you want to make the Poodle even more efficient? What are the scenarios in which you would use the improved Poodle, and which engines it would replace in those scenarios?

It's easy to say that one figure or another should be changed, but would it really make any difference? And if it made the difference, would the change have any unintended consequences?

[prophet_01]

The efficiency of the poddle is ok. My problem is that 2.5 m payloads are almost always too heavy for the poddle. I won't launch an upper stage with roughly 0.4 twr. So I have to use the skipper or a cluster of the 909's. My point is that the poddle is not particulary bad, but in most cases too weak for a 2.5m upper stage engine. I always have that niche of relatively light payloads that are still too heavy for a poddle, but oo light to justify the use of a skipper

[Jouni]

The efficiency of the poddle is ok. My problem is that 2.5 m payloads are almost always too heavy for the poddle. I won't launch an upper stage with roughly 0.4 twr. So I have to use the skipper or a cluster of the 909's. My point is that the poddle is not particulary bad, but in most cases too weak for a 2.5m upper stage engine. I always have that niche of relatively light payloads that are still too heavy for a poddle, but oo light to justify the use of a skipper

I've used the Poodle successfully as an upper stage engine for 10-30-tonne payloads, usually with a single X200-16 fuel tank. The key idea is that the amount of fuel in the upper stage should only depend on the engine type. As you increase the size of the payload, you get less delta-v from the upper stage, but because the burn time doesn't change, you still have a high enough TWR for circularization. It's easier to adapt the lower stages for the payload, because you have more degrees of freedom when designing them.

[herbal space program]

it's pretty much useless for anything but landers.

That's not a big enough niche for you? Even so, I'd still call it a decent general-purpose orbital maneuvering engine. It's also with a low profile and enough thrust to power a Tylo lander. I know nukes are more efficient for orbital maneuvering, but sometimes you want more thrust than they can provide, the Poodle works well in those situations. If you ask me, what's missing from the stock engine portfolio right now is something equivalent to the KW Orbital Bertha. I use that engine all the time, because stock has a big gap between 200 and 600 KN of thrust.

[herbal space program]

The efficiency of the poodle is ok. My problem is that 2.5 m payloads are almost always too heavy for the poodle.

If your lower stages can get you to a 50 km apoapsis, then a Poodle should be enough to circularize a pretty decent-sized payload. If you're just flying a basic Munar return mission, you can easily use the same stage to get your lander package to LMO as well.

[LethalDose]

I don't think the problem is the Poodle's numbers (Mass, ISP, TWR). I think the Poodle's numbers are great for an upper-stage engine, and I use it frequently for orbital maneuvers with medium sized payloads.

The problem is that players are calling for re-balances and stating the engine is "really useless" because it doesn't fit their play-style. The engines don't need to adhere to some formula. There are a hundred "right" ways to play the game, so if an engine doesn't work for you, don't use it. But that doesn't constitute justification for a re-balance, especially since so many other players use the engine successfully in the their play-styles.

Now, this isn't an argument that "balance is useless" or "balance is impossible" or some other reductio ad absurdum argument. It's incredibly important, but it's one of the hardest parts of a game to get right because of the variety of play-styles and strategies that have to be taken into account. There was an engine re-balance back in 0.24 that really improved the game IMO, because things were seriously out of whack with a bunch of new engines. Not just one.

[Jouni]

If you ask me, what's missing from the stock engine portfolio right now is something equivalent to the KW Orbital Bertha. I use that engine all the time, because stock has a big gap between 200 and 600 KN of thrust.

The stock solution to that is either using dual LV-T30s for 430 kN of thrust with 2.5 tonnes of engine mass, or using a tweaked Skipper for 0-650 kN of thrust with 3 tonnes of engine mass. Surely their specific impulses are a bit lower than with the dedicated vacuum engines, but that's just a 5% difference in delta-v.

In general, you can always use engines that are too powerful for the task, as long as they are not too heavy.

[RAINCRAFTER]

'A reasonable engine for rough economic times" pretty much sums up my use for the poodle - disposable 2.5m upper stages.

Not sure I agree on the 909 though, it's pretty handy - especialy early in a career game.

Your'e right, the LV 909 is cool!

[Laie]

The problem is that players are calling for re-balances and stating the engine is "really useless" because it doesn't fit their play-style.

Basically, there's three things coming together:

• the 38-7S is way overpowered -- in almost every use case where the 909 or Poodle should rule, the 38-7S is better. And cheaper, too.
  
• in many designs, the center spot is reserved for the docking port, while the engines are mounted radially.
  
• 220kN is an odd number. Most use cases require a lot more, or much less.
  

The first is an objective fact -- check Traverts charts. The other two are arguably a question of playstyle, but I'm of the opinion that the game is funneling the players' decisions towards designs where the Poodle would be out of place. Just for the fun of it, browse the last handful of Jool-5 submissions (link in my signature) and the designs people are coming up with. I guess you'll be hard put to find anything that could have been built as well or better with a Poodle.