Kerbodyne S3 KS-25x3G, The MK3 engine of the future!

[MKI]

I don't make any direct suggestions, but this is probably the most direct suggestion I've ever made for this game. I want this to be implimented sometime AFTER .90 and definantly before 1.0

I don't even know how useful these forums are at getting anything actually implimented. But as a player and a KSP fan, I really believe in this idea. Im sure I'm not the only one, and I'm sure my idea can be fine tuned. But regardless I want this badly, ever since I have started playing this game I always knew what I wanted to build and my dream is amost here with the addition of MK3 parts, but there is still one thing missing.

A Space Shuttle Engine

Or more techincally, a high gimbal engine designed to handle asyemetric launches thats expensive (to prevent exploiting) and limiting (also to prevent exploiting)

So here is my idea:

Kerbodyne S3 KS-25x3G

Product Description

Designers found that limiting the S3 KS-25x4 Cluser to 3 engines allows for unprecedented amounts of gimbal control. This combined with an new Cluster arrangment takes this engine a whole new direction than any engine before it.

(A formal follow up to the S3 KS-25x4 engine, which is modled after the SLS main engine cluster. Which is created using old Space Shuttle engine designs the RS-25's, so it should all come full circle and the game should add an engine that reflects something that took 100+ missions into space)

STATS:(anything with a ~ is up to debate)

Radial size Extra large

Cost (total) ~28 000.00 Fund (needs to be cheaper than the KS-25x4 in theory since its less engine right?, but still VERY expensive due to new technology and the fact its designed to come back from every launch)

Mass (total) ~7.25 t (Can't be to heavy since its designed for spaceplanes, but also cant be lighter than the KR-2L. But being very light could make it imbalanced. )

Drag 0.2

Max. Temp. 3600 K

Impact Tolerance 20 m/s (possible buff here? as it needs to return to land)

Research Tech tree ? (Should be in the MK3 branch, which I assume will be changed in .90)

Unlock cost ? (Again hard to determine due to changes in the MK3 branches)

Part configuration Size3EngineCluster

Maximum thrust ~2800 kN (EXACTLY 25% less thrust than the KS-25x4, could be decreased to compensate for gimbal)

Isp (1 atm) 320 s (same as KS-25x4, could be changed for balance, but this makes sense statistically)

(vacuum) 360 s

Thrust vectoring 7 -10+ °

This is hands down the most important stat. The reduction in thrust, should techincally go to this. But I know KSP acts kind of funny when an engine has high gimbal ranges. But this is also the main point of the engine. The KS-25x4 is better in terms of thrust, and bang for your buck. At the cost of being heavier. Both are fairly effecient as base level engines, with the biggest difference coming in gimbal ranges.

Now the whole point of this engine is to carry ANYTHING on a straight path into space. Nothing more, just like the KS-25x4 does for Rockets, this should do for spaceplanes. So this engine should be able to handle Asyemetric designs and movements in fuel easily, all with its gimbal. It also should find worth in being able to be returned compared to most average SLS designs. Obviously, like the KS-25x4 this engine should prevent anything from being attatched below it. Its a first stage engine, nothing more ever.

I know most dedicated Shuttle engine mod generally have engines bent at an angle, which could be done with this engine, but I personally do not care to much. As long as its easy to modify in game to bend manually, or the Gimbal ranges handle such high ranges I would be happy.

Why this needs to be done

The Space Shuttle Program was easily a third of NASA's space history. Its a large reason for why their is an ISS, its recognized accross the word as a space faring vessel. It took hundreds of Men and Women to space. In truth it wasn't very effective in the end, and this also will be mirrored in the game (an SSTO would always be more effective in terms of money than a Shuttle System) but it was invisioned to be much more effective. (This game would offer a middle of the road, with no upkeep costs to keep the Shuttle from being to ineffective)

It can act as a bridge between the two hanger created crafts, taking elements of both all to create something that goes to space in sync. It would make the Large MK3 parts a SPH counterpart to the SLS parts of the VAB. It would be able to utilize the Cargo Bays from the MK3 pack without any worry, just as the SLS parts can handle almost any cargo of the VAB.

Finally, Shuttles should NOT be as difficult to build as they are now. Shuttles are almost non existant, with almost their whole difficulty lying in the fact there is no engine for them. SSTO's are easier to build, run and use and yet they haven't existed in real life yet.

All of it lies with is that gimbal range. The Engine specs are there, the Shuttle's wings, body, and cargo bay are all there. The fanbase is there (KSO, Suttle engines etc) the want is there (MK3 parts are just as anticipated as the SLS parts) but all that is mission is the engine to carry all of it to Stock KSP.

Post up, the game needs this, those MK3 parts need this, the community needs this, I need this, and the world needs this (lol)

Edited December 7, 2014 by MKI

[Frozen_Heart]

I've asked about this same thing quite a few times and with the new shuttle parts its even more important.

Last time I actually got an official answer which was that the old joint and ASAS system, combined with high gimbal range was found to shake the rocket to pieces. However both of these issues are now sorted.

As for having a prebuilt engine cluster that only fits onto MK-3 parts.... Just no.

It ruins creativity and takes away options to build anything else apart from that exact thing. I hate many of the SLS parts already for this exact reason. We should be supplied with adaptors and the individual engines to use however we want.

This would allow other uses such as a Mk-1 or Mk-2 space shuttle or a highly manoeuvrable rocket.

Apart from that yes I like the idea.

[Random Tank]

TWR of 39.369 (more than the already OP KR-2L's 39.206), same efficiency as a KS-25x4/Mainsail, and actually gives more dV than the KS-25x4 because it's lighter?

Nahh.... Thanks, but the game already has enough OP engines, doesn't really need a new one...

EDIT: Oh, and one more thing; 2800kN is not 75% of 3200kN, 2400kN is. But even that amount of thrust would still make the engine have a higher TWR than the KS-25x4, when really it should be a lot less...

Edited December 7, 2014 by Random Tank
More problems with idea

[Frozen_Heart]

TWR of 39.369 (more than the already OP KR-2L's 39.206), same efficiency as a KS-25x4/Mainsail, and actually gives more dV than the KS-25x4 because it's lighter?

Nahh.... Thanks, but the game already has enough OP engines, doesn't really need a new one...

EDIT: Oh, and one more thing; 2800kN is not 75% of 3200kN, 2400kN is. But even that amount of thrust would still make the engine have a higher TWR than the KS-25x4, when really it should be a lot less...

The idea of a high gimbal SSME has plenty of merits, even if the stats the OP listed weren't ideal.

[MKI]

The idea of a high gimbal SSME has plenty of merits, even if the stats the OP listed weren't ideal.

Made the stats at roughly 5 in the morning, not the perfect time to be doing math calculations. I more or less eyeballed most of them, but hey the stats are all up for grabs.

I've asked about this same thing quite a few times and with the new shuttle parts its even more important.

Last time I actually got an official answer which was that the old joint and ASAS system, combined with high gimbal range was found to shake the rocket to pieces. However both of these issues are now sorted.

As for having a prebuilt engine cluster that only fits onto MK-3 parts.... Just no.

It ruins creativity and takes away options to build anything else apart from that exact thing. I hate many of the SLS parts already for this exact reason. We should be supplied with adaptors and the individual engines to use however we want.

This would allow other uses such as a Mk-1 or Mk-2 space shuttle or a highly manoeuvrable rocket.

Apart from that yes I like the idea.

The main reason i believe the engine cluster should only fit the large MK3 parts is balance. The KS-25x4 is agreeably OP. But its the biggest of the baddest, end game ultimate engine. Same could be said for this new theorietical engine. Neither could be used effeciently on something smaller, since they are designed for the hugest most rediculous missions. Using them for anything else is wasteful, especially in the fund consious career.

The MK3 parts are already coming with a number of adapters so you can use any engine you want. I personally see very few situations where you need a high gimbal engine outside of building an asymetric launch. Yes you could want a super maneuverable rocket, but why? It doesn't really offer much. What I request isn't for the manuverability but the actual ability to be more lenient on the design of your ship.

They could in the future add smaller engine classes that can represent high gimbal engines that allow players to build say MK2 space shuttles. But making MK2 Space Shuttle type designs is very ineffective for what they can do. Almost any Mk2 design would be better off as an SSTO. The same can't be said for the new MK3 parts that will probably end up carrying 2.5 sized parts and huge station parts into space that will create huge issues with thrust and changes in center of mass.

So if the smaller sizes really don't need the high gimbal, or would be a complete waste using them, why build parts for them?

Edited December 7, 2014 by MKI

[AbhChallenger]

I agree that classic Space Shuttle like gameplay should be a viable and fun way to play stock KSP. Instead of the frustrating mess it is now.

[Frozen_Heart]

So if the smaller sizes really don't need the high gimbal, or would be a complete waste using them, why build parts for them?

Because it gives us options to do what we please. If there was only a single 'best' way of doing things, why have parts at all.

Having a single KS-25 engine and an adaptor to place 3 of them would allow exactly what you are suggesting but gives us more options. There is no downside to doing it that way.

[Capt Snuggler]

not so keen on it being in the MK3 form factor. doesn't seem to be multipurpose enough. a high-gimble non-stackable 2.5 or 1.25 engine would me my choice. then it could also be used as a radial booster.

[prophet_01]

First of all, I would definetly like to have a dedicated shuttle engine. Not because I need it to get the thing into orbit, but it would make my crafts more flexible in terms of payload weight and placement. You put some effort into this and I'm quite glad that somebody opened up this discussion, so pls don't get the following wrong. The suggested numbers for the engine are a srsly overpowered. Don't forget that droptanks already add a quite significant level of efficiency to a design. An engine that allows you to use that technique extensively and also allows a considerably easy recovery doesn't need to have an (op) high isp AND a low weight. It would still be worth it if it's either heavier or a not that efficint. I would prefer heavier though.

I would prefer a 1.25 engine and an engine mount for mk3 with 3 nodes for 1.25 m parts. It could contain lfo. I would prefer an engine mount over an adapter, because I don't like structural parts of that size. They kinda favour part cliping with small structural pieces on a regular fuel tank and adding more parts to the center axis of the plane/shuttle is a source of whobble.

Btw, high gimbal could be a nice thing to have for tall landers, maybe even boosters. Also, once aerodynamics get improved, they will also be an option for wide payloads with unusual shapes.

In my opinion a prebuild cluster would leave too little room for innovative and flexible designs. It woupd not only make smaller shuttles less practical, but also make bigger ones harder. I'm not even talking about the possibilty to use that engine with big parts from mods, which should be given some thought in my opinion.

[MKI]

Because it gives us options to do what we please. If there was only a single 'best' way of doing things, why have parts at all.

Having a single KS-25 engine and an adaptor to place 3 of them would allow exactly what you are suggesting but gives us more options. There is no downside to doing it that way.

The downside is you would need to balance the KS-25 according to its own sized engines OR deal with the fact there would be a 1.25 sized engine that blows everything out of the water, the same sized or in clusters to compete with larger sized engines. (this is assumed they would be created as 1.25m engines, as that is what their size appears as, and would offer the best 3 cluster for the 3.75m parts)

Even with my rough stats I see no easy way to make a single KS-25s 1.25 meter part that is competative against the KS-25x4 cluster, and balanced against other 1.25 meter parts. You could potentially make an effort in making them 2.5 meter parts, but then their natural size would make a size 3 cluster very difficult to build without part clipping. Let alone get these single engines to become the "wonder gimbal" engine the game actually needs.

Having a cluster does force you into having it as a single best way, but it also keeps you from spamming them to make even small launch systems OP.

Again the viewpoint of this engine is in terms of career and how it would work with the new MK3 parts. Thats as far as we need to evaluate the part itself. The Devs could always throw in single KS-25's that are balanced accordingly, instead of trying to make a wonder part that needs to be balanced against its size class and competent as an engine cluster for MK3 Shuttle Designs. So I am wrong on the idea the game SHOULDN'T have single KS-25 parts, its just they don't need these parts compared to THIS part(the cluster).

The best compromise is throw in possibly 2 different varients of the KS-25 cluster beside the existing x4.

an x3, which would be the "Shuttle Engine" that would function as a main shuttle engine, and a Space Plane competator against the SLS x4 block.

and a single KS-25, which would just be a single varient of the KS-25 engine, that would offer significant Gimbal ranges at the cost of thrust compared to its larger clusters. Would be useful for MK2 designs and other interesting designs that take advantage of the high gimbal ranges.

Since we are on the topic, they should adjust a few older engines to have larger gimbal just to offer a larger variety and impact for surface landers. Since I do not believe the KS-25 engine should be used for landings that need high gimbal, something more effecient should take its place.

PS I am writing these posts at 5 AM, so please for give me for seeming a little scatter brained ;D

[AbhChallenger]

Personally I am against the idea of splitting the engine up.

The whole idea of the engine should be to enable classic shuttle gameplay on stock. Therefore the engine should be designed (Perhaps auto gimbal that adjusts to CoM on the fly like the SSME) with that in mind. There are PLENTY of other engines in the game for the other spaceflight aspects. All of which do not need a mod to be effective.

Edited December 9, 2014 by AbhChallenger

[Wahgineer]

How about this: set the engine so it can only gimbal up 10+°. What I mean:

Pitch up:10°

Pitch down:0°(add a decal so we know which way is which when we place the engine.)

Yaw left:standard (current gimbal limit on all stock engines)

Yaw right: standard

Roll left/right: standard

This way the engine can only be used for asymmetrical launchers.

[prophet_01]

How about this: set the engine so it can only gimbal up 10+°. What I mean:

Pitch up:10°

Pitch down:0°(add a decal so we know which way is which when we place the engine.)

Yaw left:standard (current gimbal limit on all stock engines)

Yaw right: standard

Roll left/right: standard

This way the engine can only be used for asymmetrical launchers.

sounds good. I already did something like that with the v-tol rocket engines from b9. If you set the options and angles right they work for that. I lifted a 100t shuttle + 45t payload with a cluster of 6 engines + 2 huge LfO boosters (piggyback design with a huge external tank)

I would still prefer the option to use more than 3 engines per cluster on my shuttle. Piggyback designs at different sizes need different thrust. It would be boring if there is only one size that works with the engines given. Of course you can adjust the angle, but that makes the design even tougher, creates problems with stability once the boosters run out and only works up to a certain limit. Adjusting the throtle works if you want to build a smaller shuttle only and would force you to carry more engine mass than necessary.

But the part that would annoy me is that the weight of the shuttle would be limited with a cluster part. If the shuttle's thrust gets too low you have to angle the engines inwards and burn toward the boosters. It looks strange and forces you to switch the engine's angle a lot once you ditched the boosters. It's possible with the mentioned b9 engine by using it's v-tol mode toggle, but it's far from ideal (or realiatic I imagine). Definetly the most bizarre craft I ever reached orbit with. But it shows how a low engine thrust can limit the function and potential of a design. A cluster has a fixed thrust and will therefore be too heavy or offer too little thrust for a number of dedigns. It wouldn't be my choice

Edited December 10, 2014 by prophet_01

[AbhChallenger]

That is why this engine needs to come with code to automatically target center of mass. Otherwise it will again be useless compared to SSTOs because of the control issues.

Is it a bit more code? Yes.. However, classic shuttle gameplay SHOULD be part of stock.

[Scoundrel]

You know, while it might add a few more parts, I think that shims that tweak engine orientation could possibly be acceptable (say in 5° increments) if the gimbal issue couldn't be overcome. They would even have use beyond just being a shuttle part.

[MKI]

You know, while it might add a few more parts, I think that shims that tweak engine orientation could possibly be acceptable (say in 5° increments) if the gimbal issue couldn't be overcome. They would even have use beyond just being a shuttle part.

These sort of parts would add a lot more to the game than just allowing engines gain higher gimbal. But one step at a time, as adding an engine with high gimbal is one thing. Adding a part that can manipulate other parts is a whole nother realm. (ahem Infernal Robotics)

I am somewhat concerned about the fact this engine will suport rather large and aggressive launches, but would be overpowered for much more "civilian" launches with MK3 parts. Asking for a middle of the road version would be interesting, but id rather get the ultimate high gimbal engine than something that will struggle. But having 2 choices would be optimal. As the SLS gives us the KS-25X4 and the KR-2L as two signifacantly different options.

PS again forgive any spelling errors or grammatical errors, its 5 AM