Foxster

Vector engine possibly a little too good?

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I'm just amused that the vector feels so over powered when in fact it's the closest ksp engines have come the performance of real rocket engines, at least in terms of thrust/physical size. Thrust to weight is still horrible by real world standards, though.

while this may be true, realistic engines are in fact overpowered because of the scale difference. they wouldnt feel overpowered at all if kerbin were 6x bigger (ie the size of earth) with vastly higher escape velocity

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while this may be true, realistic engines are in fact overpowered because of the scale difference. they wouldnt feel overpowered at all if kerbin were 6x bigger (ie the size of earth) with vastly higher escape velocity

Well one big difference is that for those numbers engines are tested without pumps, and the weight of the tanks is also in reality often higher (depends a lot on the use though, but carbon-based fuel tanks need often heating to prevent them of freezing in the upper parts of the atmosphere, then there's the extra pressurized helium that needs to fill up the empty to push out the fuel etc etc. If you add all this mass to the "engine" I doubt the KSP numbers are far off.

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No bottom node I think would just be plain annoying, we already had the aerospike spoiled by that (changed in 1.0.5, hurrah!)

A model that actually shows the engine would be good, not just for balance but also for a more consistent art style. But it can't be too long or it would cause problems for Shuttles, and the real SSME has a big bell on relatively small machinery - which is simply a feature of a vacuum-optimised engine.

I wonder if it could have simply been made a little wider? And then it could be a 2.5 m engine, fitting nicely between the Skipper and Mainsail in performance, and that bit trickier to put in a 1.25m stack (you'd need a bulging interstage fairing) or make such compact clusters out of (assuming you avoid clippingness).

If they made it any wider, it wouldn't work as a shuttle engine. That was the whole point, to make shuttles without all the clipping.

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The thing that makes the Vector look overpowered is this:

All other 1.25m engines are starter tech. They have between 14 and 17 TWR. When the tech tree then proceeds to unlock better engines, they are suddenly not 1.25m anymore - they're all 2.5m. Their TWR suddenly goes up to between 25 and 32, with comparable Isp and gimbaling across the board. When the 3.75m engines come, they pretty much conform to that same format.

As a result, there is something "missing" - an 1.25m engine that conforms to the same standards as other "high tech" engines. It's not that the other engines are overpowered, but that the 1.25m ones are underpowered due to their earlygame status. And they never get updated to the state of the art that all other engines conform to. You'd expect there to be a version of the Swivel that has perhaps 350 kN thrust. But it never comes.

Well, there was one other 1.25m rocket engine, the aerospike. But it comes extremely late, and it isn't even in the rocket branch! Additionally it has no gimbal, and a TWR of 18, not 25+. Its Isp is impressive, but its price is high and it lacks both the power and the versatility of the baseline that the 2.5m and 3.75m engines conform to. It's not a higher-tech replacement, it's a gimmick spaceplane engine unsuitable for things that get staged away.

And now, after all this time, and at the very end of the tech tree, you suddenly get an 1.25m engine that conforms to the same power level as the 2.5m/3.75m engine sets. Yes, at first glance it's another expensive gimmick spaceplane engine, introduced solely to make STS replicas work; but assuming you have the money, or play sandbox, this time you actually can use it for a rocket. It has everything a rocket engine needs and is straight up better than a Swivel in every way, just like a Skipper is straight up better than a Swivel in every way. It even has the added advantage of working well on Eve, which will no doubt make it the default Eve ascent engine from now on.

However, there's two things that make the Vector feel completely off the curve: progression and scaling. Firstly, it takes that complete lack of better 1.25m engines that everyone ignored and shoves it into the spotlight. Previously the player thought "well, maybe the huge TWR jump between 1.25m and 2.5m is justified, because it's a big jump in size, and the smaller ones simply cannot give that sort of performance." But now the Vector shows that small ones are very well capable of matching performance, and that the sudden jump isn't in any way justified. It shows just how far behind the curve the other 1.25m engines really are, and just how large of a gap there is in both tech node progression and performance where other engines should be but aren't. You look at the Vector and cannot help but feel that it is out of place, simply because there is nothing that gradually leads up to it.

Secondly, while the performance conforms to the same baseline as the other large engines, a baseline alone is a very variable thing. You can have 25 TWR with 1000 kN, but you can have the same with 10 kN. It's all a matter of scaling - you can assign it any arbitrary thrust and any arbitrary weight, so long as the math spits out a TWR of 25. And the problem is, with the second most powerful 1.25m engine topping out at 215 kN, placing the Vector at 1,000 kN cannot ever possibly hope to feel like it belongs. I mean, how many tanks do you usually put on top of your typical booster before you add another stage on top? Two FL-T800 for a Swivel, two-three orange jumbos for a Mainsail, two-three S3-14400's for a Mammoth... And now what? Ten FL-T800's on a Vector? That'll just look absurd!

TL;DR: The Vector is not overpowered compared to most other engines, but it sticks out like a sore thumb for several different reasons. I don't feel like it is a particularly good addition to the game. It just doesn't fit.

I agree with everything EXCEPT that it is a poor addition to the game. I love the heck out of it, while at the same time wanting higher-power 1.25m engines to bridge the gap. Maybe the last part Jeb's Junkyard makes for rockets in the tech tree ought to be one final high-TWR 1.25m engine: 500 kN thrust. That would help bridge the gap between the Vector and the Reliant while also giving us a rather useful size-1 rocket motor.

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One way to maybe end these types of discussions whenever any new engine is released, is to rejig engines entirely so that players select bells, chambers, pumps capacities, gimbal ranges, other enginey stuff etc. and then configure their own. Slow heavy pumps at lower end of tech, small efficient ones later on... Static bells lower in tech, procedural bell shapes later on. etc, etc. etc. might need some general smartness and creative thinking on the required modelling, scaling, cost balancing by feature, etc. Whatever... I'm sure someone somewhere has already suggested this.

Wait - then we would argue about bell shapes! Argh! ;-)

On topic - I like the vector, Victor - don't touch it.

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No it is not overpowered at all.

Everybody should be able to build a shuttle of their own. The learning curve is WAY too steep, or at least, it was.

I think it's perfect and about time too.

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Everybody should be able to build a shuttle of their own. The learning curve is WAY too steep, or at least, it was.

It still kinda is. You still need to incline the engines, though I don't think Squad could have been expected to give them like 50 degrees of gimbal capability lol.

And landing that thing... Still haven't managed it, makes you appreciate how complicated of a beast it is, if a bit in vain...

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Its a single player game. there is no such thing as "over powered". If there was such a thing then the other 1.25m engines would be better considered underpowered because the vector is logically just a fraction of a mammoth that in turn is simply a cluster of vectors no other 1.25m engine shares such a relationship to anchor its stats in and justify its numbers.

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No it is not overpowered at all.

Everybody should be able to build a shuttle of their own. The learning curve is WAY too steep, or at least, it was.

I think it's perfect and about time too.

Lol what? Learning curve too steep? It's actually quite boring since the game is so damn forgiving. Oh I tumble my rocket! - Instead of each part ripping off due to the sudden change in (aerodynamic) forces you can happily continue. "Oh crap I missed the orbit and lost a satellite" - instead of your program reaching near bankruptcy due to a few failed launches you can happily press 'reverse to launch' - or if you disabled that the money you earn is more than enough to cope for 4-5 launches.

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Lol what? Learning curve too steep? It's actually quite boring since the game is so damn forgiving. Oh I tumble my rocket! - Instead of each part ripping off due to the sudden change in (aerodynamic) forces you can happily continue. "Oh crap I missed the orbit and lost a satellite" - instead of your program reaching near bankruptcy due to a few failed launches you can happily press 'reverse to launch' - or if you disabled that the money you earn is more than enough to cope for 4-5 launches.

Sorry I should have been clearer. I meant the learning curve for shuttle building.

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The Vector is (ironically) a little OP for a stock shuttle, but it's not OP in comparison to it's stablemates.

It shouldn't be compared to the Swivel, but rather the Skipper and Mainsail.

It fits nicely between those 2 engines in the pecking order, and is ridiculously expensive.

Best,

-Slashy

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The Vector is (ironically) a little OP for a stock shuttle, but it's not OP in comparison to it's stablemates.

It shouldn't be compared to the Swivel, but rather the Skipper and Mainsail.

It fits nicely between those 2 engines in the pecking order, and is ridiculously expensive.

Best,

-Slashy

The problem is: it has several extra perks that make it "better" than the mainsail & skipper:

radial attachment ability, high performance in atmosphere, very high thrust (not talking about TWR, just the raw thrust), ridiculous gimbal motion (combine that with thrust and it shows that for lift-off this engine is perfect in stabilizing), 1.25m size.

These combined with an otherwise already competitive engine make it highly wanted. In return it should also have several "non direct' disadvantages, currently 'Thrust for buck' is the only disadvantage.

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Every time a new engine comes out, everyone says its OP.

When there are no new engines, people complain that there aren't new parts.

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The problem is: it has several extra perks that make it "better" than the mainsail & skipper:

radial attachment ability, high performance in atmosphere, very high thrust (not talking about TWR, just the raw thrust), ridiculous gimbal motion (combine that with thrust and it shows that for lift-off this engine is perfect in stabilizing), 1.25m size.

These combined with an otherwise already competitive engine make it highly wanted. In return it should also have several "non direct' disadvantages, currently 'Thrust for buck' is the only disadvantage.

It's 'high' performance hardly differs from the mainsail, it's a difference of 5 to 10 isp.

TWR is everything for a rocket-engine, which makes it as strong as the mainsail.

And the gimbal isn't even much of an advantage: Try launching a rocket with vectors and SAS, the'll regularly rip your rocket apart by oscillating widly without gimbal limit; which is already an issue for the MS.

As for free placement, that's easily done with structural parts for every engine.

The only real advantage is the 1.25m size. Which, again, isn't much of an advantage cause the thrust is far too high for a 1.25m stack. And of course the ability to stabilize crazy stuff like the shuttle system, which is already underpowered as a concept.

I'd say the vector is maybe 5% better than the mainsail. But it's super interesting and adds to the game cause of it's small size combined with high thrust+weight, strong vectoring, and free placement.

Edited by Temeter

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I think I know the easiest way to solve a lot of the supposed "problems" with the Vector's balance. Edit the part description.

Kerbodyne's flagship engine, the KS-25 excels as a first stage engine through its high thrust-to-weight ratio and exceptional sea level efficiency. Kerbodyne engineers achieved this by running the engine in a staged combustion cycle and at extremely high chamber pressures. Special new alloys had to be invented to suppress the engine's tendency to become a bomb. The single version is designed with very durable components and high reusability, as well as higher gimbal range, but because of that is also heavier than its expendable counterpart used in first stage clusters.
Kerbodyne's flagship engine, the KS-25 excels as a first stage engine through its high thrust-to-weight ratio and exceptional sea level efficiency. Kerbodyne engineers achieved this by running the engine in a staged combustion cycle and at extremely high chamber pressures. Special new alloys had to be invented to suppress the engine's tendency to become a bomb. The single version is designed with very durable components and high reusability, as well as higher gimbal range, but because of that is also heavier than its expendable counterpart used in first stage clusters. Note that this engine may have a more compact attachment point, but it IS a heavy lift engine, and is NOT suitable for 1.25 meter diameter stacks such as the FL-T and LV-T series.

This change does nothing except tell users that it is not actually meant to be a 1.25m stage engine, it just happens to be compact enough to cluster without ugly tankbutts. Let's hope the Mainsail and Skipper get overhauled like this as well in the updates to come. There really is not reason for tankbutts to exist anymore.

Edited by GregroxMun
changed 5/4m to 1.25m to avoid confusion with "5 or 4" meter instead of "five divided by four" meter.

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TWR is everything for a rocket-engine, which makes it as strong as the mainsail.

Well if that's all then yes it's not "strong". - But problem is, that is not all. I_Sp, size for landing, costs, amount of drag. Dead weight while doing small corections. Free thrust when doing large burns and being able to them exactly at the peri/apo apsis. Instead of adding an inaccuracy by starting 1 minute ahead. It's all important, and depending on the mission different ratings are given.

And the gimbal isn't even much of an advantage: Try launching a rocket with vectors and SAS, the'll regularly rip your rocket apart by oscillating widly without gimbal limit; which is already an issue for the MS.

It gives the opportunity to use it: it's not necessary if you already have high enough corrective moments.

As for free placement, that's easily done with structural parts for every engine.

Lowering the TWR, increasing the drag (larger size).

Oh and an increase of I_sp by 1.5% is huge.

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Well if that's all then yes it's not "strong". - But problem is, that is not all. I_Sp, size for landing, costs, amount of drag. Dead weight while doing small corections. Free thrust when doing large burns and being able to them exactly at the peri/apo apsis. Instead of adding an inaccuracy by starting 1 minute ahead. It's all important, and depending on the mission different ratings are given.

It gives the opportunity to use it: it's not necessary if you already have high enough corrective moments.

Lowering the TWR, increasing the drag (larger size).

Oh and an increase of I_sp by 1.5% is huge.

It's not 'free thrust'. Every bit of weight lowers D/V, which is everything. Hence it's stupid to go for a Vector when a skipper suffices. Latter has better VAC ISP btw. As for corrective thrust, that's already something the mainsail can do. If that kind of vectoring isn't enough, then you're in huge trouble. Seriously, I can't every imagine when a vector would have save me. Aside from a shuttle maybe.

Made a small test vehicle, 2.5m capsule, locked 9t tank, orange fuel tank below: 2290 vs 2254 delta-v. Not that much. Increase fuel to 5000 d/v, and we'll get 80 d/v advantage. Again, the skipper has even better vacuum ISP.

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This change does nothing except tell users that it is not actually meant to be a 1.25m stage engine.

Since when do we actuallly use stuff as intended? The sheer amount of crazy whackjob designs goes to show that people will use engines or parts in the way they see fit, and not in teh way Squad or anyone invisioned them to be used. Myself, i use many parts as kinetic projectile weapons (i do alot of stock combat), and that alone is very much not how squad intended them to be used. Heck, even ive done some odd stuff. Ive used massive engines like mainsails as RCS thrusters on 1000t ships. Ive used engines on rovers to push them downward and keep grip on the surface. Ive used engines that were obviously the wrong size for the stack to propel said stack (back before 1.0 aero at least).

Now as to the vectors, i feel they arent exactly OP or UP, although they are very good engines.

Im defenetely gonna try a scaled down EVE SSTO with them though since someone used the super massive quad engine in a single stage eve spaceplane. It was just too large for my tastes, but the new engine wit similar stats should work with a smaller design.

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I really think we need a new Eve-like but harder planet.

This combined with the aerodynamic changes have made the ascent so much easier.

Eve used to be the "final boss" of the game, now it is just laythe+ without jet engines.

I don't think the radial attachment or small size really make it more OP.

Cubic struts allow very easy, light and cheap attachment and clipping makes part shape mostly meaningless for gameplay.

Edited by Joonatan1998

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It's worth pointing out that vector engine has a benefit over 2.5m / 3.75m engines when you play career and want to recover spent stages space-x style:

- You need less stages (mostly just one stage) to move thing to orbit thus it's easier to recover this stage (in stock game) and recover funds as opposed to more stages that are needed with 2.5m/3.75m engines.

=========================================

Let's compare:

3.75m rocket able to lift 80t to 100km orbit (roughly). For simplicity reasons I don't count the cost of recovered parachutes/core probe/landing legs since in both cases it is roughly the same. Payload cost is also excluded from calculations.

=========================================

Vectors = you can just attach 9 at the bottom (space-x style - little to no clipping like that) building single lean column.

Mammoth = you need more than one column meaning radial decouplers and radial staging. You cannot efficiently recover those stages (at least in stock) since you need to control ascent of the rocket instead of landing 2 to 8 boosters / radial stages. The cheapest way I did this is 1 mammoth and 8 x biggest boosters.

=========================================

Cost of putting 80 t to LKO:

- 1 mammoth + 8 boosters = 108.656 funds , recoverable = (38%) 41.56k (16k for 1 mammoth and rest for 4 empty tanks).

- 9 vectors = 227k, recoverable = 193.95k (85%) (162k for 9 vectors and 31950 for 5 empty tanks)

In other words final cost of putting 80 t to LKO:

- 1 mammoth + 8 boosters = 108656 - 41560 = 67096 funds

- 9 vectors = 227000 - 193950 = 33050 funds

Pics (in both cases payload mass = 85395kg, payload cost = 19720)

3oilrR8.png

DhDNUQn.png

However to get 100% recovery rate you need to land near KSC which is also quite difficult, so I would say that from recoverability perspective vectors are quite balanced since you need 100% recovery rate to make them competitive to other options.

Edited by riocrokite

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Now as to the vectors, i feel they arent exactly OP or UP, although they are very good engines.

They highlight the fact that the standard 1.25m engines stink.

For the sake of Mk2 parts, something much better than Swivel or Reliant wouldn't be amiss -- at least 250kN, possibly up to 400kN from a single 1.25m attachment node, preferably with a TWR/ISP that isn't worse than Skipper or Mainsail. The Aerospike isn't bad, but has it's own issues and is still somewhat underpowered; and the 1000kN Vector is just as useless as the Reliant.

Ceterum censeo: crank up the nukes while you're at it. Any vessel that's worth a nuke can do with much more than 60kN. Everybody's thinking of the children, but what about the motherships?

- - - Updated - - -

It's worth pointing out that vector engine has a benefit over 2.5m / 3.75m engines when you play career and want to recover spent stages space-x style:

Plus, 20m/s impact tolerance allows you to use fewer chutes. Don't slam it down on the runway unless you want to build a new one, though.

Edited by Laie

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I don't know. Maybe it should be put at 800 thrust? It might be balanced in career mode, but the vector is kind of high power for a 1.25m part.

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[quote name='Motokid600'][I]"If something is overpowered in this game then your payload is not large enough." - Me.[/I][/QUOTE]"If something is overpowered/unbalanced in this game, it's for spaceplanes."-Me ;)

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It costs a ton. Enough said. Unless you are using it like I do and have it propel chemical SSTO rockets the cost and tech expense is not worth it. I think it is perfectly fine, it is great for SSTO craft, but costs a ton to use making it restricted to re-usable roles and possibly some exotic return vehicles.

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