The Vector: Your thoughts

[Temstar]

You can't make 1.25m engines too good across the board though, back in the days when LV-T30 and LV-T45 had better Isp than 2.5m engines every man and his dog who knew a thing about clustering clustered 1.25m engines instead of using 2.5m engines. Nerfing them made Skipper and Poodle useful again.

Vector is toeing a pretty good line being nearly identical (although slightly worse TWR) to 1/4 of a Mammoth, so if you consider Mammoth acceptable then Vector should be acceptable too. It outperforms Mainsail in all stats except thrust per dollar. If all 1.25m engines were this good then once again no one will use 2.5m engines.

[LostOblivion]

I believe that one of the goals of this game is that any real-life vehicle recreation, like the US Space Shuttle, should roughly perform the same when it looks the same. Given that the obvious intent of the Vector is to provide an analog to the SSME, it is utterly too powerful. I agree it makes sense when compared to the Mammoth, but as a standalone shuttle engine, three of them on a shuttle replica gives too much thrust by a factor of between two and three times. On my shuttle replica I have to limit their thrusts to 1/3 to maintain below 10 % shuttle thrust ratio (IRL it has 5 %!), meaning I could actually make do with only one of these...but I cannot, since then it would no longer look the part. Nerf!

Also, remember that the rocket the Mammoth was based on, the Saturn 5 or SLS (rockets haven't changed much, have they...), had five such engines, not four, warranting at least a comparable reduction in thrust, and perhaps a model change for the Mammoth to get five engines.

[monophonic]

1 hour ago, LostOblivion said:

Also, remember that the rocket the Mammoth was based on, the Saturn 5 or SLS (rockets haven't changed much, have they...), had five such engines, not four, warranting at least a comparable reduction in thrust, and perhaps a model change for the Mammoth to get five engines.

At the time of the Asteroid Redirect Mission release, the IRL plan for SLS had four RS-25 engines and two twin-engine liquid boosters, just as KSP offers. I believe the plan has since evolved so it now has 5 engines in the main stack and new solid boosters to replace the interim lengthened shuttle boosters. So what you see now on the SLS fan sites does not entirely match up with what KSP models.

For the Saturn 5, remember that it's opposite number on the eastern block, the N-1 had what 30 engines on the first stage! Rocket engines haven't changed that much, but launch vehicle designs have, and keep changing a lot.

[Frozen_Heart]

7 hours ago, Temstar said:

You can't make 1.25m engines too good across the board though, back in the days when LV-T30 and LV-T45 had better Isp than 2.5m engines every man and his dog who knew a thing about clustering clustered 1.25m engines instead of using 2.5m engines. Nerfing them made Skipper and Poodle useful again.

Vector is toeing a pretty good line being nearly identical (although slightly worse TWR) to 1/4 of a Mammoth, so if you consider Mammoth acceptable then Vector should be acceptable too. It outperforms Mainsail in all stats except thrust per dollar. If all 1.25m engines were this good then once again no one will use 2.5m engines.

I think there should be a choice about how we use engines. Either in 1.25m clusters or as a single 2.5m engine. Both should be viable with different pros and cons. It makes it so there is more variety in people craft depending on what they prefer.

[NathanKell]

Despite their looks, the Mammoth and Vector are really more modeled on the RD-171 and RD-191 respectively. This is because KSP does not deal with different propellant mixtures; everything is storable hypergolics (so perhaps the RD-275 is a better counterpart, really), and because KSP does not have large high-thrust solids to make a central sustainer viable in 3.75m. (Recall that thousand tonne core of the SLS is so wide only because of the low density of hydrogen; it would be the same diameter as the RSRMs otherwise, each of which are 600 tonnes.)

[MaxL_1023]

Now that you mention it, I would like to see some cluster-type engines in stock KSP. Cluster 4 Reliants together, give them a thrust bonus and a little less weight overall and say that the Kerbals took a mainsail turbopump and hooked it up to 4 Reliant chambers. 4 1.25m engines would make a perfect 2.5m part, potentially with higher TWR and efficiency than the skipper or mainsail at the expense of raw power. 

Also, in RSS that RD-171 is insane. Makes the F1 A/B look like an old pile of junk. 

 

 

[moogoob]

As an aside to this discussion, it may not be useful in career due to cost and late arrival, but has anyone tried making their own engine clusters using (say) the size-3 to mk3 adapter as a tank butt? Twenty-one of them firing at the same time (with gimbal limits, of course) is very impressive on a three-core launcher.

Managed to bring 160-something tons of payload to orbit in one go. TWR for the win!

[Dobelong]

I can't decide if it's great or too OP, so I'll let the picture do it instead.

I raced a vector and a skipper once...

The skipper was repurposed as a mop

[nosirrbro]

Is it overpowered? Yes. Do I want it removed? No! Is it fun as hell? Yes!

[Spartwo]

I've entered into a committed relationship with the vector.

[monophonic]

2 hours ago, Spartwo said:

I've entered into a committed relationship with the vector.

I read that as a "committee relationship" the first time... 

[Workable Goblin]

On December 9, 2015 at 5:38 AM, Frozen_Heart said:

I think there should be a choice about how we use engines. Either in 1.25m clusters or as a single 2.5m engine. Both should be viable with different pros and cons. It makes it so there is more variety in people craft depending on what they prefer.

Well in reality the rationale for clusters versus large single issues largely boils down to reliability. If, like Glushko, you don't think that you can build large engines, then you will probably go for clusters of small engines, because you can actually make the engines work (in theory). As a nice bonus, you can use the same engines on upper stages without them being hideously oversized, which in theory will save you money. If, on the other hand, you're the United States and you figure that there's no issue with a million and a half pound engine, then you will probably go for big engines because standard theory predicts fewer bigger engines will generally be more likely to work out, all else being equal.

But there's no notion of reliability in KSP (and thank God for that, in my opinion; I get plenty of excitement from design and planning issues, without adding parts randomly failing. I had quite enough of that in BARIS, thank you), so there's no real reason to favor one over the other. They should really be approximately equivalent.

[LaytheDragon]

The Vector just isn't useful for 1.25 meter things, despite it's size, so it should be compared to 2.5 meter engines instead, which are much more on par.

Edited December 27, 2015 by LaytheDragon

[ShadowZone]

Guys... the Vector is fine as it is. Please leave it alone. Thanks

[Speeding Mullet]

I've only got to use it for my Buran replica so far, and given the massive offset loads involved (with the Buran shuttle not firing it's engines before orbit) the Vector has come in extremely useful, indispensable should I say.

Despite this I do find the engine does hunt a lot which induces large wobbles without a very well designed craft.  Reading through the thread it looks like this can be attributed to something which will get ironed out though so I am over-all very pleased with the engine.

SM

[Mad Rocket Scientist]

I honestly couldn't care less if it's OP or not.  KSP is still fun to play, and the vector doesn't change that, OP or not.

[Francois424]

Just now, Mad Rocket Scientist said:

I honestly couldn't care less if it's OP or not.  KSP is still fun to play, and the vector doesn't change that, OP or not.

And if anyone finds it OP they can just open the partname.cfg file and change it to say, 500 thrust.
By the time you get it anyways you had to play (mostly) to the end-game of science.

[Snark]

1 hour ago, Francois424 said:

And if anyone finds it OP they can just open the partname.cfg file and change it to say, 500 thrust.

Or, indeed, just install this mod, as @fourfa mentioned earlier.

"Is the Vector OP" is one of those unanswerable questions, like "Is MechJeb cheating?", because it is completely subjective and everyone has to decide for themselves.

For me, it's ridiculously overpowered-- fully a quarter of the Mammoth's thrust, packed into a ninth of the area, and made surface-attachable to boot.  In my world, that's so overpowered that if I left it as-is, I would never ever use it simply because it feels so much like "cheating" to me that it would be a letdown.  (It's the same reason I never use the science lab.)  Which would be a pity, because it's a cool engine and I wouldn't get the benefit of its having been added to the game.  So I mod it to have stats (thrust-per-area, cost-per-thrust, gimbal amount) that are in line with the Mammoth, and then suddenly it's an interestingly cool engine that lets me do neat things without feeling like a cheat.

But that's a wholly idiosyncratic reaction on my part and has nothing at all to do with what's "right".  Everyone needs to decide for themselves.  Clearly some people find it OP and want to tone it down (the mod has had plenty of downloads).  Clearly, lots of other people love it just as it is (see the discussion in this thread).  The nice thing about KSP is that it's so easily moddable that everyone wins. 

 

[Geschosskopf]

I find the Vector.........interesting.  Great stats in all respects except weigth, cost, and insane amounts of gimbal.  Personally, I regard engine gimbal as the Plague and usually disable it, especially with engines that have gobs of it like the Vector, so my review will ignore that feature.  And I never do shuttles so to me it's a question if thrust, Isp, weight, and cost.

Within those parameters, I've found the Vector must useful in clusters for an upper stage of a lifter, but I don't normally need it for that role.  It also  occasionally works by itself as an interplanetary transfer stage depending on payload mass.  But both of these are fringe markets, and otherwise I don't have any real use for it.  Thus, I don't find it OP, it's just an engine that fits into a few specific roles better than other engines.  But I don't have need of any of its optimal fits very often so I don't use it much.  Thus, I don't see any reason to change it.

[Dfthu]

I used 5 Vectors with limited gimbal for my main lifter so it must be useful. The gimbal really helps to control th rocket when it flips. I dont think it is OP.

Edited December 28, 2015 by Dfthu

[322997am]

Vectors tear my ships to shreds. I use them only on a 50% gimbal limit because when sas gets engaged it starts bending the rocket because of the insane gimbal

[Fearless Son]

59 minutes ago, 322997am said:

Vectors tear my ships to shreds. I use them only on a 50% gimbal limit because when sas gets engaged it starts bending the rocket because of the insane gimbal

Something similar: I ended up using a pair of Vectors on radially-mounted fuel tanks to move my ship, and the gimbals end up causing my ship to list side-to-side under acceleration, like it is "waddling" along.  

Which is why I named it the "Duck".

[NathanKell]

Talking about size? Guess it's time for this again.

Of the following two engines, which do you think produces more thrust?

Engine 1, with a 2.14m diameter nozzle

 

Engine 2, with an approximately 1.3m diameter nozzle (the 4.9ft stated appears to include the pump).

 

[Majorjim!]

On 12/09/2015 at 10:24 PM, NathanKell said:

Despite their looks, the Mammoth and Vector are really more modeled on the RD-171 and RD-191 respectively. This is because KSP does not deal with different propellant mixtures; everything is storable hypergolics (so perhaps the RD-275 is a better counterpart, really), and because KSP does not have large high-thrust solids to make a central sustainer viable in 3.75m. (Recall that thousand tonne core of the SLS is so wide only because of the low density of hydrogen; it would be the same diameter as the RSRMs otherwise, each of which are 600 tonnes.)

Can we have some bigger, more useful SRBs? Thanks.

[AlamoVampire]

With the gimbal dialed WAY back its a great motor. Needs tweaking on the gimbal but its a good motor