1.875m parts

[Frozen_Heart]

So 1.875m parts is something that I've thought would be a good idea for a long time and have brought up in the past, but I think the topic is relevant again if the rocket parts are going to get the spaceplane treatment.

From what I can see KSP spacecraft are roughly half scale compared to their real life counterparts, with the SLS parts and space shuttle parts almost confirming this. However to keep this going for a huge number of real vehicles, 1.875m parts are needed. Soyuz, Atlas, Falcon 9, Shuttle SRBs, and Antares all fit into this rough zone. It fills a nice sweet spot between minimalist satellite launchers and heavy lifters, and I suspect that these parts would become very heavily used.

I addition the current SRBs used for the shuttle are very underpowered due to their 1.25m size, meaning that the Vector has to be incredibly powerful to make up for it. The RL space shuttle gets over 70% of its thrust from its two boosters, while the KSP shuttle only gets around 40% of its thrust from them.

 

[John JACK]

1.25, 2.5 and 3.75 parts have ratios 1:2 and 1:1.5 in diameter. It may seem very close, but.

Section, meaning surface area, drag and engine thrust, is proportional to linear size squared. That are 1:4 and 1:2.25 ratios. Gap between "size 1" and "size 2" already looks bigger.
Volume, meaning mass and capacity, is proportional to linear size cubed. 1:9 and 3.375 ratios. In game largest 2.5 m tank has 8 times more fuel than largest 1.25 m tank, and largest 3.75 m tank is just 2.25 times more than largest 2.5 m one.
And rigidity, meaning amount of force to bend something for a given deformation, is proportional to linear size fourth power. Thought bending force by itself is proportioal to length, so 2.5 m rocket is to be just 8 times more rigid than 1.25 m one.

Also, in spaceplane parts Mk1 size is 1.25 m, Mk3 size is roughly 2.5 m, and intermediate Mk2 has no rocket analogue.

There are mods that add 1.875 m or close size parts. But not big and not popular.

So — stock 1.875 please! Or maybe 1.75 or 2 m size, rounder numbers may be better than exact ratios. Also MOAR bigger boosters!

[KerikBalm]

then we'd need a whole new set of engines, cockpits, probe cores, batteries, reaction wheels... etc... I'm not sure its worth it.

However, we could definitely use some bigger SRBs, and 2.5m seems like overkill for them.

Perhaps a 1.875m SRB that already has a "nosecone" on it/has low drag as if it had a nosecone (and like the goliath, or other parts, if you put something on top, it gets a fairing).... or maybe the top  tapers to a 1.25m node, and you can put a 1.25m stack on top, or just a nosecone, or parachutes, etc.

Maybe also a 1.875 LFB with a taper at the top to 1.25m... such would avoid all the problems of making another node size

[Rath]

I  am an avid user of HGR, and I support this.

 

 

[Frozen_Heart]

1 hour ago, KerikBalm said:

then we'd need a whole new set of engines, cockpits, probe cores, batteries, reaction wheels... etc... I'm not sure its worth it.

However, we could definitely use some bigger SRBs, and 2.5m seems like overkill for them.

Perhaps a 1.875m SRB that already has a "nosecone" on it/has low drag as if it had a nosecone (and like the goliath, or other parts, if you put something on top, it gets a fairing).... or maybe the top  tapers to a 1.25m node, and you can put a 1.25m stack on top, or just a nosecone, or parachutes, etc.

Maybe also a 1.875 LFB with a taper at the top to 1.25m... such would avoid all the problems of making another node size

I'd be happy with just a 1.875m SRB with a 1.25m node on top for a nosecone. It makes things simple and easy for the devs while keeping the possibility of more 1.875m parts open in the future.

[March Unto Torment]

If I recall, SpaceY actually has something like this; a 1.875m SRB with a 1.25m node at the top. I could be wrong, but I'm pretty sure that it's too small to be a 2.5m booster. I use four of them on my mainline (40t to KEO) launch system. I'd definitely endorse the idea.

[John JACK]

4 hours ago, KerikBalm said:

then we'd need a whole new set of engines, cockpits, probe cores, batteries, reaction wheels... etc... I'm not sure its worth it.

We still need new 2-kerbal reentry pod, for times when Mercury is not enough, and Apollo is too much, and using plane cockpit in a rocket is just weird. And we need some engines near 400 kN thrust, in between Swivel and Skipper.
Cockpits are for Mk2 size, proposed 1.875 "size 1½" is for rockets. Mk3 and 3.75 lack probe cores and reaction wheels too, so not every size must have them. There are neither Mk2, Mk3 or 3/75 m inline batteries.

What do we really need is a command pod ot two, service bay, four LFO tanks, monoprop tank, pair of engines, one ore three SRBs, some adapters and nosecones. And most of al we need official acknowledgement for that size really exists and what precise diameter it should be. 1.875 is good, but 1.75 and 2.0 m are okay too and rounder numbers.

[KerikBalm]

1.75 adn 2.0 aren'ts as nice, as it is currently everything is a multiple of 0.625m, the smallest parts.

Indeed, if we exclude the 0.625m parts themselves, then everything is a multiple of 1.25m parts (2.5=1.25*2, 3.75 = 1.25*3)

 

I'm not sure I really see the demand for a 2 kerbal reentry pod, any more than I see the demand for a 4 kerbal one. I'm also not so sure on the 400kN engine need when we already have a 250kN engine. I think some of the 1.25m engines need a buff rather than adding a whole new size (but thats another thread, which already exists).

Of course, you could make yourself a 4 kerbal reentry pod by stacking 2 lander cans behind a heat shield. Maybe the mk1 lander can needs a rework to be more cylindrical, and not stick outside the standard 1.25m radius as much. Then your two kerbal reentry capsule can be parachute>mk1pod>mk1can>heatshield

[mattinoz]

15 hours ago, KerikBalm said:

then we'd need a whole new set of engines, cockpits, probe cores, batteries, reaction wheels... etc... I'm not sure its worth it.

However, we could definitely use some bigger SRBs, and 2.5m seems like overkill for them.

Perhaps a 1.875m SRB that already has a "nosecone" on it/has low drag as if it had a nosecone (and like the goliath, or other parts, if you put something on top, it gets a fairing).... or maybe the top  tapers to a 1.25m node, and you can put a 1.25m stack on top, or just a nosecone, or parachutes, etc.

Maybe also a 1.875 LFB with a taper at the top to 1.25m... such would avoid all the problems of making another node size

or they limit the number of parts in this much need in between size to make it part of the challenge?

Have it more like the 0.625 parts that are really limited but in the opposite way to the 0.625 parts. Only have a few parts make them on the largish size.

So no batteries, no engines, no probe cores, no reaction wheel,... etc...

To me one tanks size, one SRB both the length of an orange tank. Limit service parts to one decoupler, one heat shield, one cockpit, one Faring . 6 parts all up. Although a Service Bay would be handy. We can use radially attached Tail connectors to add engine mounts like we do with 2.5m tanks and multiple 1.25 engines.

 

[KerikBalm]

How are .625 meter parts limited?

Battery

numerous probe cores

reaction wheel

intake

LFO tank

LF only tank

Xe tank

4 inline engines

3 radial engines of appropriate size

monoprop tank

decoupler

seperator

docking port

No need for a service bay unless you add even smaller .3125m parts to go in them :/

All they really need now is tiny retractable landing gear... although a more powerful jet engine would be nice.

[NotAgain]

I think a lot of you should check out the Bluedog Design Bureau mod. It contains various sizes, including 1.875m, 1.5m, 1.75m (I think), 0.9375m, 0.3175m and 0.125m parts for launchers and payloads. And a 2-kerbal pod (1.5m) and heat-shield for it. It also has kerbalised versions of Atlas (I,II and V) Titan, Vanguard, Redstone, Juno, Diamante, Delta (I and II) and Thor. There are probably others that I've forgotten about. It also has various early probes (mainly American). It's really memory efficient, and I am an avid user.

http://spacedock.info/mod/442/Bluedog%20Design%20Bureau

http://forum.kerbalspaceprogram.com/index.php?/topic/122020-wip-105-bluedog-design-bureau-v010-älter-2532016/#comment-2205042

[Darnok]

On 10.04.2016 at 0:11 PM, KerikBalm said:

then we'd need a whole new set of engines, cockpits, probe cores, batteries, reaction wheels... etc... I'm not sure its worth it.

 

Or few flat and not only flat adapters?

[mattinoz]

16 hours ago, KerikBalm said:

How are .625 meter parts limited?

Battery

numerous probe cores

reaction wheel

intake

LFO tank

LF only tank

Xe tank

4 inline engines

3 radial engines of appropriate size

monoprop tank

decoupler

seperator

docking port

No need for a service bay unless you add even smaller .3125m parts to go in them :/

All they really need now is tiny retractable landing gear... although a more powerful jet engine would be nice.

All those parts and getting off the ground and into orbit is stuff of legend.

The size in the game has a very limited role unless you get creative. 1.85m parts could be treated the same way and geared to a limited in game role. Inspiring creative outcomes.

I think 0.32 parts are great. USI Sounding Rockets mods to me proves there should stock parts in this size.

[KerikBalm]

Thats funny because I've made multiple working SSTOs with 0.625m parts... including ones with all the reusable science equipment, antennna, and electrical storage and generation - both airbreathing and pure rocket (and in the case of pure rocket- with aerodynamic surfaces to allow it to glide and have an easier reentry)... though the junos performance... like a wheesley or goliath... is pretty poor and the pure rocket did better.

[Capt Snuggler]

On 10/04/2016 at 11:11 AM, KerikBalm said:

then we'd need a whole new set of engines, cockpits, probe cores, batteries, reaction wheels... etc... I'm not sure its worth it.

not necessarily. if @Porkjet does auto tankbutts for the engines in his polishing of stock parts, (like in Ven's Stock revamp) you could put almost any engine on any size tank.

for an intermediate part size you could probably get away with:

• 2 LF/O tanks. med and small. (for upper stages)
• 1 decoupler.
• 1 two seater Command Pod.
• 2 SRBs. tall and short. (rescale the S1 kickback)
• 1 up scale adapter.
• 1 down scale adapter.
• 1 fairing base plate.
• and maybe 1 service bay.

10 parts aint that much.

Edited April 12, 2016 by Capt Snuggler

[John FX]

To do this would require more parts, as has been said. This would greatly increase confusion for new players.

or

Implement procedural parts and tweakscale into stock then you can have 1m,1.1m,1.2m and so on up to 18m and you can scale engines, pods and cores to match perfectly.

I notice some people are saying the new parts would just be rescales of existing parts anyway so why not just put a tweakable onto the solid booster for example then you have all the boosters in 1 part...

[Frozen_Heart]

2 hours ago, John FX said:

To do this would require more parts, as has been said. This would greatly increase confusion for new players.

Science / career mode solves this already by limiting what parts are available. The first few nodes have very similar parts to what we had when we first arrived at KSP.

[legoclone09]

Maybe just add it like how 3.75m was added. 4 fuel tanks, two engines, and a decoupler. But we would need an inline battery (2000 EC?) and a docking port as well as structural adapters. Maybe they could have NecroBones help with it since his textures for the stock fuel tanks are amazing.

[John JACK]

2 hours ago, John FX said:

This would greatly increase confusion for new players.

Career progression! New players will get 1.875 m parts only after being already familiar with 1.25 m. And 1.875 m parts will be less confusing than that HUGE 2.5 m.

2 hours ago, John FX said:

and you can scale engines, pods and cores

No you can not. Scale tanks — maybe (though still no), but engines and pods are complete and complex units by themselves, they must be totally remade for any changes. 3-kerbal pod is not a single kerbal pod three times bigger, and 2-kerbal pod is not average of 1 and 3. KSP is lego, and lego is good, we just want some new bricks for it.

20 minutes ago, legoclone09 said:

like how 3.75m was added.

It will be good too. Also 1.875 is mostly a booster/lower stage size, so no batteries or even docking ports are needed. Just adapters to smaller and bigger size.

[Knaapie]

 

Always happy to solve every issue in this topic

 

/edit: Yes the rocket parts could use an update, not to be able to create real life rockets, but for balance issues. That is what the focus should be on.

I understand the urge to replicate real life (or even star wars), but please understand that it is a never ending wishlist, completely solved by tweakable parts.

Edited April 12, 2016 by Knaapie

[John FX]

27 minutes ago, John JACK said:

No you can not. Scale tanks — maybe (though still no), but engines and pods are complete and complex units by themselves, they must be totally remade for any changes. 3-kerbal pod is not a single kerbal pod three times bigger, and 2-kerbal pod is not average of 1 and 3. KSP is lego, and lego is good, we just want some new bricks for it.

Yes, yes you can. No parts do not have to be remade for any scale changes.

From the OP of tweakscale

"Scaling Control

You as the author of a part or addon get complete control over which parts you want to offer in which sizes. Should that fuel tank only be available in size 2.5m and 3.75m? Make it so! That RCS thruster on the other hand, could be scalable freely between half regular scale and double regular scale.

Mass Control

For heavy, solid parts, mass increases with the cube of the scale - you scale it in three dimensions, after all. For parts that are a thin layer of aluminium plates over a rigid skeleton - like fairings, crew compartments, empty fuel tanks - mass probably scales closer to the square of the scale.

Control Over Every Feature of a Part

This is not all! Engines can be made more powerful as they increase in size, generators more efficient, and wings more lifty. All by writing a simple config file, and then automatically for all rescalable parts of that type." (emphasis is mine)

Also recently I saw posts from new players who were complaining that there were too many parts and they were forced to play career when they actually wanted to play sandbox but the sheer number of parts was too daunting so new players who would want to skip career were being forced to use it as a tutorial that lasted far far far too long.

There is more to KSP than career and there is more to KSP than sandbox, players should not be forced to use a playing style they don`t want to because of overcomplexity due to bad practice or because of another players preferred playing style.

Edited April 12, 2016 by John FX

[RocketSquid]

And how would adding more parts make the game more complicated than adding an entire tweakscale mechanic? If I was a new player, starting in sandbox, I would use my typical approach to sandbox games: Throw stuff together, or maybe watch a tutorial and then throw stuff together. If there were 1.875m parts, I would say, "Oh, okay, there are 5 sizes of parts". If there was just a tweakscale mechanic, I would say, "Wait, what? What's this weird tweakable for? Huh? Why would I be able to change the size of this thing?" or I would miss it entirely.

Also, if "we can just change the size of existing parts" is a valid reason not to add something, why don't we just fully implement tweakscale and remove all of the part sizes except 1.25 m? After all, if there are fewer parts, that's less confusing.

If 1.875m is going to be implemented, as it should be, it should come with its own unique parts for diversity and simplicity. A good template would be how 1.875m tanks were implemented in Angel-125's Mark One Laboratory Extensions, which adds NO 1.875m engines, instead using a simple adapter part.

[Knaapie]

I like what Angel-125 did. It looks amazing.. and the mk1 hitch hiker cabin can be useful and the adapters look so much better. Thankfully these things have suggested over and over and have become parts in the common suggestions links.

The same thing can be said for the 1.875 parts, they have been suggested over and over and the OP has made his point in the common suggestions links as well. Well done.

 

So.. the subject has had its attention. and yet, here we are again.. Trying to inspire Squad to fulfill an "ultra late game" need: "aesthetics". Because something looks different in real life.. for this reason the OP is directed towards tweak parts, There are simply too many real life craft to be made with a hand full of parts.

This doesn't mean these parts will never be a part of stock. Squad is sensitive for what their fans would like to see. And this would create some new variations for rockets, it allows a 2 manned crew cabin and fits in the same place as the newer space plane parts. I also liked how Angel-125 created a shorter research lab (the stock lab is a bit long). I'd almost like to see how it would work in early career. 

All good stuff. But for now: use tweak parts. And note that this already is a commonly suggested topic. Squad is aware of this idea for a long time.

Edited April 12, 2016 by Knaapie

[The Great Potato]

48 minutes ago, Knaapie said:

So.. the subject has had its attention. and yet, here we are again.. Trying to inspire Squad to fulfill an "ultra late game" need: "aesthetics".

There's a very real need for a size 1.5, especially in career. Aesthetics are a part of this, sure, but you can say the same of any suggestion for parts.

Playing stock recently, most of my rockets need something with more power than size 1, but size 2 is complete overkill. Just look at John JACK's math in the second post - that is the best indication of the problem. There's also an uncomfortably large gap in the tech tree between the Reliant and the first Rockomax engine. During that time, the Reliant is it. The most powerful engine in your arsenal can barely lift 15t.

Better hope you upgraded the VAB - you're gonna need a lot of parts.

[John JACK]

6 hours ago, John FX said:

This is not all! Engines can be made more powerful as they increase in size, generators more efficient, and wings more lifty. All by writing a simple config file, and then automatically for all rescalable parts of that type." (emphasis is mine)

In other words, it's a cheat.

Right, there are no cheating in a single player sandox. But there should be at least some balance, to ensure usefulness of any part, not just one Twitch or LV-909 for every size. Engines of different sizes have different stats and are not just scaled for a reason. Tanks, batteries and wings in stock are actually scaled, but for simplycity only.
Also different stats in different sizes is realistic. You can not scale nature, and for example engine bell of twice size will not provide same ISP with quad thrust. Smaller structural parts are relatively more strong but bigger parts are more rigid. Not even mention fourth dimension, like gimbal rates or spool-up times. They use clusters of smaller parts instead one big all the time, from laptop batteries to Merlin engines. One big engine IRL may have better ISP, but be heavier and less reliable because greater mechanical stresses. And of course bigger engines cost much more, even big enough machines to make parts are very rare and in high demand.

TweakScale may be okay as a mod, to allow people do whatever they want for their own goals and funs. But that mechanic is totally unsuitable to stock game due to being at same time unrealistic, unKerbal and unbalanced.
 

I think, reasons there are no 1.875 m size in stock are mostly historical. Once upon a time, there were only three sizes: "normal" 1.25 m, "tiny" 0.625 m (half size) and "big" 2.5 m (twice size). But then Squad added "huge" parts, and not double size again (5 m) but just one-and-half of previous. That set a precedent of sizes being closer. Next was Mk2 size, that is wider than 1.25 m Mk1 and lighter than 2.5 m. So why not do the same again and incorporate a "size 1½", even just nominally? Or stock some mod with that parts and community will do as always.