The Vector: Your thoughts

[ryan234abc]

Alright!

I really dunno if this thread has been done yet, or if I'm putting it in the right section - the new layout is still, well, new to me.

This thread is gonna be about the new Vector engine. Is it OP? Do you like it? What would you change about it? All your thoughts and opinions regarding the engine are welcome here! If you want to post your craft photos featuring the engine, feel free! Is it's Vector, it's fine to put here! I'll start this off - I LOVE the Vector engine - the gimbal and thrust coupled with its small size makes it ideal for those Mk1 size ships that need an extra boost.

Post everything Vector here!

Ryan

[Norpo]

I will say this; even if the Vector is imbalanced/balanced, it's really fun to play with. There was a big discussion over this a while back, and someone made a good point; it's not balanced with the other 1.25m engines, but it's TWR is in the same tier as the 3.75m/NASA parts. The reason it seems so out of place is because it is, it's TWR is in the same tier as the 3.75m engines, not the underpowered 1.25m engines. It's balanced out in Career mode by being unlocked roughly around the same time as the 3.75m engines, and costing about the same. It just so happens to actually be a 1.25m engine.

[cantab]

This has been discussed before. To me it goes back to the ARM engines being all wrong, since the Vector is a quarter of a Mammoth. They both reflect the Shuttle engines. To my mind the Mammoth should be less powerful but perhaps more efficient, the Vector taking the same effect, while the Kickback should be considerably higher thrust. This would also help correct one of the problems KSP shuttles have, which is too much thrust and mass in the orbiter compared to the boosters and ET. The real Shuttle stack had only 20% of its thrust and 5% of its liftoff mass in the orbiter, not much off-centre mass to cope with.

But then I'd like to see the whole engine lineup rejigged.

Edited December 6, 2015 by cantab

[Frozen_Heart]

I love the Vector but it could do with 1/2 -2/3 the thrust it has now. I've had to thrust limit it to 50% on my Mk-3 shuttle to get it balanced as I previously used skippers. I hope that all engine butts get removed in future as they are completely pointless.

Edited December 6, 2015 by Frozen_Heart

[panzer1b]

Its a nice engine, since it gets similar performance to the massive quad one, but allows that to be utilized on a smaller craft.  That said, i still use nukes for most roles that dont involve lifters or landing super heavy loads, so its not an engine that ive been using regularly, and the quad one is better for a purely lifting engine.

[Hannu2]

In my opinion it is ridiculously overpowered for normal rockets in my playstyle. It destroys all fun for example Eve ascents. It may be expensive compared to other engines, but if I do not play some supergrindy ultrahardmode I have millions of extra money when I unlock Vector and price means practically nothing. I could say same thing about other large 3.75 m engines. There is not actual need for these in the game. I can make very easily rocket for any purpose, just put few huge tanks and engines and fly it on orbit. It was more fun before when single launch Eve rocked had about 1000 parts and 700 of them was struts. It took hours to develop monsters and about 20 minutes to fly them to orbit.

[KerikBalm]

Its got worse TWR than a mammoth, but better gimbal...

I don't think we needed it, as the rotate tool allowed us to make shuttles just fine:

(Ok, the landed one was 1 version earlier than the VAB shots)

I find the gimbal range to be way higher than needed, and I often limit the gimbal when I use it because the gimbal is just too much.

That said... I find that its great for Eve ascent vehicles. Aerospikes have an OK TWR, but I'd prefer if they had more mass and more thrust... too little thrust per stack... Eve ascent vehicles from sea level are still rather short and squat with aerospikes.

Meanwhile I found a pair of vectors provided plenty of thrust for my 3 kerbal lander+ascent vehicle. As it is, I used a mk1 pod+ mk1 crew cabin atop a fl-t400 with a terrier as my upper stage. The lifter was a core stage of an aerospike, with two stacks of fuel tanks(feeding the aerospike) with vectors underneath... then an additional two stacks of fuel tanks feeding into the vectors... these stacks had no engines at the bottom.... before my problem with eve sea level ascents was was having enough nodes to attach engines to/having enough thrust per node.

Now with the vector, I'm using stacks with no engines at the bottom. If they halved the thrust and mass, I'd make an even more efficient eve ascent vehicle, because after the drop tanks (the fuel tank stacks with no engines underneath) are jettisoned, I throttle back.

If the thrust and mass were reduced by 50%, I wouldn't complain... it may be power creep, but I feel that the 1.25m engines with the excepton of the aerospike and LV-N are pretty bad at the moment.

Maybe the terrier is ok... but as compared to the KR-2L or poodle, it seems to be rather... meh.

I don't use any (non-airbreathing) 1.25m engines aside from the aerospike, LV-N, terrier, or vector after I've unlocked the whole tech tree... but I really only consider using the vector for Eve, or novelty shuttles (which so far still aren't working as well as my KR-2L shuttle did in 1.04)

I don't think the vector is OP, just that most 1.25m engines are under powered... not just relative to the 3.75m engines, but also the 2.5m ones.

[Francois424]

I've had to limit the vectoring to 10° on most of my new launch vehicles using it, otherwise because of the Gimbal/ASAS bug the ships would tear themselves apart.  Trying to VTOL down on Kerban with full vectoring was crazy hard to do.
That said I really like the engine.  It feels like a chemical nuke engine, very heavy, 1.25m so fits anywhere, and quite situational.

Now we're only missing a 600ISP chemical 100 thrust engine, a 250 thrust 2,5m nuke engine, and 2 ions (1,25m/20 thrust and 2,5m/100thrust)

[Frozen_Heart]

Quote

600ISP chemical 100 thrust engine

As a chemical rocket with that kind of ISP is completely impossible I doubt that will get added. The best a chemical bipropellant rocket engine can get is about 455s.

[Red Iron Crown]

It's awfully powerful for a 1.25m engine, so much so that it's too much for a single stack while retaining any sort of rigidity. It's a great 2.5m lifter engine though, with the additional benefit of reduced drag when mated to a 1.25m-2.5m fuel tank at the bottom.

I guess it works well for shuttle replicas, but that's not an overly efficient type of rocket and is extremely finicky to get working well.

[Jouni]

The Vector has become my standard lower stage engine for 2.5 m rockets. The Skipper has always been a bit too weak for first stages, while the Mainsail is almost always too powerful. As a 2/3 Mainsail, the Vector is just the right size for most 2.5 m rockets.

[RocketSquid]

The vector's advantage isn't high thrust, or even high TWR. Its vectoring and TVR (Thrust-to-volume-ratio, A term I made up) are the best of any rocket engine, meaning it is disproportionately powerful for its size. Fortunately, its weight, cost, and high tech level make it balanced.

[fourfa]

If you're interested in repurposing the Vector some, there's this:

http://forum.kerbalspaceprogram.com/index.php?/topic/125433-105-vector-repurposed-tweak-vector-to-be-a-rocket-not-spaceplane-engine/

[problemecium]

The problem here is that the KS-25 Vector is literally 1/4 of the KS-25x4 Mammoth (hence the name). In thrust, mass, and efficiency it performs exactly the way a quarter of the Mammoth would. So rebalancing it would make it all weird and illogical unless they changed the name... okay I suppose they could change the name.
That or redesign the Mammoth, e.g. nerf the Vector and then make the Mammoth consist of eight of them or something.

[Motokid600]

Squad should really consider getting rid of ALL the tank butts on all the engines to help compensate for the vector.

[KerikBalm]

18 hours ago, parameciumkid said:

The problem here is that the KS-25 Vector is literally 1/4 of the KS-25x4 Mammoth (hence the name). In thrust, mass, and efficiency it performs exactly the way a quarter of the Mammoth would.

1 mammoth is 15 tons. 1/4 of 15 tons is 3.75 tons... the Vector's mass is 4.0 tons.

Also, when you don't limit the gimbal, it will often gimbal way too much... aside from often  making the rocket shake itself apart, it also increases cosine losses.

Rocketsquid:

I like the term "Thrust to Node ratio"... or Thrust to Cross section ratio.

The vector's stats for these are amazing... the aerospike... not so much (which is why I want an aerospike thrust and mass increase) It can lift an obscene stack of FL-T800 tanks... far too tall for it to handle it structurally... so in the end, its not that useful.

I've stil; had more luck with the KR-2L, as pictured above, for spaceshuttle type designs. I just tried the design again last night (hadn't tested since 1.04), it still works in 1.05... (but the margins are very low) I tried replacing the KR-2L with 2x vectors (and replacing the rearmost orbiter tank with once more aerodynamic and suited for the vector... I ended up with a Mk3->mk2 adaptor instead of a mk3->3.75m adaptor, and then a mk2 bicoupler... which has just 45/55 LF/Ox less fuel... I never got within 300 m/s of achieving orbit... so its not that... its the vacuum ISP I guess..

[problemecium]

Meh. I don't know what it is I'm doing differently, but I rarely have any trouble at all with engine gimballing.

And okay, I guess it does weigh a bit more than 1/4 of the Mammoth, but my point regarding trying to nerf it still stands, if it isn't bolstered. Making it more "accurate" would end up making it even more "OP", so if it gets nerfed it's doomed to become much less deserving of the KS-25 designation.

[Archgeek]

All this talk of "tank butts" -- just what is a tank butt?  I do hope you're not refering to the turbopump and combustion chamber assemblies.  Those are known for pretty important.  One of the dopier things about the Vector is that it's just a black attachment disk with a gimbal bearing and a bell.  Of course, this is to emulate how the rest of engine was set inside the structure of the shuttle with SSMEs, but shouldn't we take a fuel penalty when attaching it, then?

[Red Iron Crown]

The tank butt is the fairly hemispherical cap that matches the tank size. Ideally tank butts would be part of the tank parts rather than engines, to make mixing and matching look better.

[GoSlash27]

It's a 2.5m engine with a 1.25m footprint. It's good for making shuttles, but that's about it. It doesn't really do anything useful that can't be done with a Skipper or a Mainsail. Plus it's crazy- expensive and shows up late in career.

 Not an engine I'd find a use for outside of the sandbox.

Best,

-Slashy

[Temstar]

I think Vector is pretty good, it reflects its real life counterpart the RS-25 quite well in that both are high Isp, fairly powerful, high gimbal range and catastrophically expensive if you use them as disposable engines. Which then ties in well with RS-25E / Mammoth as these are cheaper versions of the same engine designed to be expandable. If you are using Vectors in expandable rocket stages then you are basically throwing money at a problem to solve it.

The only thing that really throws you off about Vector is it's small size. RS-25 and RS-25E are not super duper powerful engines in a small physical package, and I have no real problem with Mammoth either because it has an enormous superstructure above the engine nozzles that you can visualise in your head contains all the thrust structure and turbomachinery. The problem is on its own the Vector is only represented by its engine nozzle, so in a physical package about the same size as a Reliant it packs five times the thrust. That's the only part that's really jarring.

Perhaps the solution is to make it really long like the nuke engine with all its turbomachinery out on display. Then have a special hollow adapter for shuttle clones that you can attach to the bottom end that will hide all the engine innards when it's attached.

Edited December 8, 2015 by Temstar

[Psycho_zs]

IRL SSME are surprisingly compact: https://en.wikipedia.org/wiki/File:Pratt_Whitney_Rocketdyne_space_shuttle_main_engines.jpg

But still, Vector has too few 'guts', especially compared to Mammoth.

[MaxL_1023]

The solution I advocate is introducing upgraded versions of the Terrier and Reliant. The vector is basically a swivel on steroids (more gimbal, thrust, etc) - there should be a Vactor derivative which trades the gimbal for mass/thrust and a Vacuum engine with about 400 ISP. 

[juanml82]

I haven't yet used it to replace Mainsails, but I'm getting the impression it's more of a booster engine than anything else. Once you're in orbit, it's Terriers, Aerospikes and Rhinos if you also want thrust, or Nervs/Dawns if you can live with longer burn times.

I'm building a medium sized 6 passenger ferry and I find it's best to use the aerospikes or the nervs rather than building a shuttle type of thing with drop tanks and SRBs and end up in orbit with a ship equipped with heavy, not so efficient engines.

[RocketPilot573]

I am perfectly fine with this engine. Using skippers for a shuttle was always annoying due to the huge tank butt, and the thrust was always quite lacking once you put a full sized external fuel tank on it. Really all that can be done is to remove the tank butts from all engines. Many people dismissed the idea of those jet engine turbines because they where so big and thus limited creativity. Are tank butts not the same?