[WIP][1.8.x] SSTULabs - Low Part Count Solutions (Orbiters, Landers, Lifters) - Dev Thread [11-18-18]

[Shadowmage]

So are you going to make an Ares rocket from Constellation?

Not directly, no. But most of the part should already be available for you to build Kerbalized analogues (such as the 5-segment SRB for the Ares I first stage... which is actually my current preferred method for launching the CSM stack; much cheaper than the full liquid-fueled setup). Think I've got a pic somewhere....

Ahh, yes, there it is:

[blowfish]

The ICPS though, has been balanced towards being a dedicated range-extender for the CSM stack to enable Mun/Minmus operation (and is likely useless for any other purpose).

I get that, but I think it's underpowered even for that purpose. In my testing I recall getting ~700 m/s out of it with the CSM on top, which isn't even enough for a trans-munar injection. I'd recommend at least increasing the fuel amount to put the delta v at 1200-1500 m/s, which is enough for final circularization around Kerbin (assuming a shallow ascent path) and then a trans-munar or trans-Minimus injection.

[Shadowmage]

I get that, but I think it's underpowered even for that purpose. In my testing I recall getting ~700 m/s out of it with the CSM on top, which isn't even enough for a trans-munar injection. I'd recommend at least increasing the fuel amount to put the delta v at 1200-1500 m/s, which is enough for final circularization around Kerbin (assuming a shallow ascent path) and then a trans-munar or trans-Minimus injection.

Hmm.. something must be off between my balance sheet and the in-game numbers then, as my sheet says it should have ~1050 dV with the CSM mounted. Still probably a bit lower than I would like; however when I had it set higher I would constantly find myself -returning- from the Mun with the ICPS still attached (and full fuel in the SM), or finding myself with the choice to jettison a half-full ICPS or attempt to land it on Minmus (bad idea btw, its too tall and likes to wobble, landing just the CSM is much easier).

Will take a look at the #s to find out why the balance is off from what is supposed to be. Will also consider increasing its capability slightly, though it likely won't be in the 1500 m/s range... probably closer to the 1200 range.

Honestly I should probably just apply stock balancing to it, and up the base dV on the CSM to allow it to perform its own Kerbin-SOI (Mun/Minmus) missions unassisted (Mun/Minmus dV requirements are so laughably low, my 2nd stage usually does most of the insertion burn anyway). As really the ICPS is barely needed as-is, and always will be for any reasonable balance on the CSM. Using stock balance I could repurpose the ICPS as a true upper stage, one that could be used to send the CSM (and possibly small lander) to some of the lower-dV interplanetary destinations.

Tough call....

[Shadowmage]

RL-10A-4-2N

RL-10B-2-1

[_Augustus_]

Not directly, no. But most of the part should already be available for you to build Kerbalized analogues (such as the 5-segment SRB for the Ares I first stage... which is actually my current preferred method for launching the CSM stack; much cheaper than the full liquid-fueled setup). Think I've got a pic somewhere....

Ahh, yes, there it is:

http://i.imgur.com/WrGC3S6.png

Yes, but your J2-X will make it actually possible to make an Ares I.

[Shadowmage]

Have been working with JoseEduardo over the past couple of days to get RO/RSS/RF/MFT compatibility sorted out, and it looks like things are off to a good start. Jose and StratoChief et. al. have put together a set of MM patches for RO that apply realistic scales, masses, and performance values to most of the Series-B upper stage parts and engine clusters.

And Jose and I spent a good deal of time yesterday getting RealFuels/ModularFuelTank support for the Ship Core customizable fuel tanks (works independent of RO, but was needed for RO compat). So, now you have multiple options for fuel-switching in the tanks depending on how you want to go about it and what mods you have installed.

The Real-Fuels compatibility will be available with today's update. I'm not sure on the timeline on the RO config set, but I believe there was a link posted a few posts back if anyone were interested in trying out the WIP stuff.

Also looking into a couple other small bug-fixes and balance changes for this update, but overall it will be a fairly small update (none of the engine stuff is even close to ready for initial testing).

Yes, but your J2-X will make it actually possible to make an Ares I.

Ahh, yah, point taken. I suppose I should work on getting a few more of these engines finished off then?

That is actually my plan for the rest of the weekend I think (after I pack up the release); I think I have a decent enough selection of basic engine geometry that I can begin working on the basics of the next stage (fuel routing, mounting, and gimbals). Hopefully I can pull this off as I am intending to, will be quite the fun little set of parts.

[davidy12]

About RO... Are you guys going to add real plume soon?

[Shadowmage]

On the note of balance;

I'm personally very torn on how to balance the CSM/ICPS stack. It is a hard bit to figure out satisfactorily. On one hand, I want to maintain consistent balance across parts. On the other, I want to custom tailor the parts for their intended purpose, but the differences in mechanics between real life and the KSP world make it difficult.

I have a few intended routes to investigate (in no particular order):

Option 1: CSM as Mun/Minmus capable craft, with ICPS for interplanetary

CSM dV: ~1800

ICPS (with CSM) dV: >3000

Total dV: ~4800

Should allow for CSM to be lifted alone, and perform Mun/Minmus operations unaided. ICPS is balanced for stock, and should be usable as a generic upper stage.

Option 2: Uhh...no clue what to call this one

CSM dV: ~900- quite capable on its own, though not quite mun/minmus capable (maybe just barely...)

ICPS dV: ~2400 - semi-balanced for stock, intended to be used heavily for circularization burn, possibly usable as generic upper stage for small payloads

Total dV: ~3300

Option 3: Overpowered for Mun/Minmus, but not quite enough for real interplanetary missions. Basically gives loads of margin for sloppy burns or rescuing lots of kerbals. This is close to how I had it balanced several weeks back. Was very 'usable', but I personally found it a bit OP (but probably should have left it, as it worked fine...).

CSM dV: ~1050 - not quite enough for an unaided Mun/Minmus mission, but plenty for return-to-kerbin burns + orbital adjustment on the way back (e.g. can return to visit a station on the way home before de-orbit).

ICPS dV: ~1400 - plenty for mun/minmus burn and injection, though perhaps a bit short for allowing it to be used for circularization as well.

Total dV: ~2450

Option 4: Mimic real-life performance, scaled for KSP; ICPS needed for...everything, but ICPS not very capable as its own upper stage.

CSM dV: ~ 500 (enough for rendezsvous, or return from mun/minmus burn)

ICPS dV: ~1500 (possible small circularization burn, trans-munar insertion, munar orbit insertion)

Total dV: ~2000

CM has mass increased, propellant decreased. ICPS propellant increased; neither is really balanced in regards to stock.

Any preferences as to the performance of the CM/SM/ICPS parts? Any balance#'s you would like to see in place? I'm pretty open to all of the options I posted, and would even consider examining a few more if anyone has ideas / specific #s they would like to see. I might even see about doing some MM patches for each, and let people choose which balance they want (eventually... still need to decide the standard balance).

- - - Updated - - -

About RO... Are you guys going to add real plume soon?

I believe StratoChief said he would look into it after they finished the initial set of RO configs. So, yes, it sounds likely, but no, I have no idea when.

[davidy12]

Great to hear!!! Can't wait to see the plumes hope they come soon

On a side note, the CSM of the Orion is about 1100 m/s. So I'd go with that.

PS: Another thing that has been bothering me, the bottom engines (4 thrusters around the SPS) are supposed to be high powered RCS thrusters not actual engines.

- - - Updated - - -

Also the core stage for RO has only 220 m/s of DV when stretched to realistic length.

- - - Updated - - -

Also, you need to look at the nodes for RO. (Decoupler)

[Shadowmage]

Great to hear!!! Can't wait to see the plumes hope they come soon

On a side note, the CSM of the Orion is about 1100 m/s. So I'd go with that.

PS: Another thing that has been bothering me, the bottom engines (4 thrusters around the SPS) are supposed to be high powered RCS thrusters not actual engines.

- - - Updated - - -

Also the core stage for RO has only 220 m/s of DV when stretched to realistic length.

- - - Updated - - -

Also, you need to look at the nodes for RO. (Decoupler)

I do not offer RO support, not really my deal (unless its low-level plugin compatibility stuff). Though JoseEduardo or StratoChief might be able to help you out if you ask nicely.

One big thing though, the RF support for the fuel tanks is not publicly available yet (needs plugin update on my end, and MM patches to enable it with the RO stuff), so it likely will not work properly at the moment.

Should have the compatibility in place on my end with the release later today, and the set of patch configs are still being worked on and finished up.

[JoseEduardo]

Great to hear!!! Can't wait to see the plumes hope they come soon

On a side note, the CSM of the Orion is about 1100 m/s. So I'd go with that.

PS: Another thing that has been bothering me, the bottom engines (4 thrusters around the SPS) are supposed to be high powered RCS thrusters not actual engines.

- - - Updated - - -

Also the core stage for RO has only 220 m/s of DV when stretched to realistic length.

- - - Updated - - -

Also, you need to look at the nodes for RO. (Decoupler)

That will be fixed once the next update comes out, the tanks in the repo aren't working with the current release, I already submitted a Pull Request with the updated one (which won't work with the current SSTU version), and we're just waiting for the SSTU update to have it merged to the repo

And I believe we didn't look at the decouplers yet in the configs, as Shadowmage said it is a WIP config

[Shadowmage]

Sweet, that is good news.

Working on SRB FX at the moment; have them nearly in line with KW rocketry stuff. The only bit I haven't figured out is the scaling... apparently stock effects don't have any support for scaling; and as KW rocketry uses a rescaled model, its effects are scaled in an odd manner without any way to duplicate it on an unscaled model. They are still much improved though, both the sound and visual fx. Might just see about whipping up a custom particle that allows scaling, but I'll likely save that for another time.

Quite a few other balance changes, tweaks, and improvements coming for this update as well (if I can get them all done...). Will have a full list later on with the release.

Should have everything ready here in a couple of hours, maybe less if I quit playing with the FX stuff.

[JoseEduardo]

Shadowmage, would it be possible to add in a future update the forward skirt of the SRBs?

It seems that the 5-segment SRB will also use them

[Shadowmage]

Updated test release is available:

https://github.com/shadowmage45/SSTULabs/releases/tag/0.2.14-beta

See the link for downloads and full change-log.

Highlights include:

RealFuels support for custom fuel tanks (optional, no configs included, see the RO patch set for configs, or ask for instructions)

Better FX for the SRBs

Rebalanced SRB thrust (heat/emissives not done yet)

Rebalanced ICPS and CSM stack

Procedural decoupler now has stats!

Few other bugfixes

[blowfish]

I had a thought about the SLS upper stages: Rather than attempting to tailor them to specific use cases, why not make them semi-adjustable? The flat ribbed sections look like they could be tiled pretty easily. It might not work perfectly with your stretchable tanks module (particularly since the fairing would have to be adjusted too), but I don't believe it would require too many changes and most of them would be on the code side rather than the assets side. Just a thought

Also, is there a usage guide for the lander parts? What's the midpoint node on all of the fuel tanks for? Both nodes on the decouplers appear to face the same direction - is that intentional? How would I stack things in order to set up multiple stages?

[Sudragon]

Would it also be possible to implement a disarm function on the DPM docking port/parachute module?

[Monsterlunch]

Holy cow. Im stoked.

This is art! Can't wait to test this as soon as I get home.

[Shadowmage]

Shadowmage, would it be possible to add in a future update the forward skirt of the SRBs?

https://mix.msfc.nasa.gov/IMAGES/HIGH/7776231.jpg

It seems that the 5-segment SRB will also use them

Seems like I could add them as nose-cone variants; though I'm a bit unsure as to the purpose? Seems like (for KSP) they would just add some height/mass, but nothing useful?

I had a thought about the SLS upper stages: Rather than attempting to tailor them to specific use cases, why not make them semi-adjustable? The flat ribbed sections look like they could be tiled pretty easily. It might not work perfectly with your stretchable tanks module (particularly since the fairing would have to be adjusted too), but I don't believe it would require too many changes and most of them would be on the code side rather than the assets side. Just a thought

Also, is there a usage guide for the lander parts? What's the midpoint node on all of the fuel tanks for? Both nodes on the decouplers appear to face the same direction - is that intentional? How would I stack things in order to set up multiple stages?

My intention on the upper stages is to have them quite configurable, similar to the fuel tanks (may even use the same plugin... undecided). Will know more once I finish up the engine stuff; still a bit too early to start digging into details on these.

Lander Parts - no guide as of yet. Midpoint on tanks is for the decoupler. Yes, they are both suppose to point the same direction, else you could not use them on the tanks properly. Staging for those parts, using the LC decouplers, is an inner-stage/outer-stage affair rather than top/bottom.

In order to use the decouplers, take a LC fuel tank and set it to a hollow variant. Add the decoupler to the part on the center node. Add a second (smaller) LC Fuel tank to the node that is on the decoupler (might need to add stuff to the top/bottom nodes of the original fuel tank before it will let you snap stuff). They are omni-decouplers, so it does not matter which stage stays attached to the ship. You can (kind of) see these in use on my Tylo lander example (in the LanderCore Imgur album on the main post).

Honestly, those things worked out to be a bit more tricky to use than I would have liked, and I'm considering a simplification of the lander core parts to only include the standard solid fuel tanks. Though some of the opportunities they provide are interesting, and I'm not sure I could do some designs without them.

Would it also be possible to implement a disarm function on the DPM docking port/parachute module?

Not sure what you are referring to? Disarm what?

It is using stock modules; so if the option is available on the stock docking port or parachute, then yes; otherwise no.

[JoseEduardo]

IDK how this could be done in one single part, but they could be used for parachutes and the nose cone for srb separation, this way if you pick just the nose cone you get srb separation, if you pick both, you get parachutes (useful for career) and srb separation

[Shadowmage]

IDK how this could be done in one single part, but they could be used for parachutes and the nose cone for srb separation, this way if you pick just the nose cone you get srb separation, if you pick both, you get parachutes (useful for career) and srb separation

None of that is doable within a single SRB part. The staging action is already used by the main motor; so you cannot have either parachutes or separators. This is a very low-level stock KSP limitation that I can do nothing to solve.

[riocrokite]

hey Shadowmage,

Minor (avoidable) bug occurs when you set your switchable tank as a vessel root part. Upon reload (or relaunch) tank reverts to its original texture and other vessel parts disappear. This doesn't seem to happen when the part is not a root.

[Shadowmage]

hey Shadowmage,

Minor (avoidable) bug occurs when you set your switchable tank as a vessel root part. Upon reload (or relaunch) tank reverts to its original texture and other vessel parts disappear. This doesn't seem to happen when the part is not a root.

Hmm.. that sounds bad. Will add it to the issue tracker and begin investigating for a solution for the next update. Seems there is a different processing/loading order for root parts compared to others, which has caused problems with numerous other mods as well (e.g. tweakscale, procedural parts). Will see what I can do though.

[riocrokite]

Hmm.. that sounds bad. Will add it to the issue tracker and begin investigating for a solution for the next update. Seems there is a different processing/loading order for root parts compared to others, which has caused problems with numerous other mods as well (e.g. tweakscale, procedural parts). Will see what I can do though.

Yah, it seems to affect only big fuel tanks (which have multiple mesh switches + texture switch). Cabins / lander tanks seem to work ok as a root part.

[Shadowmage]

Getting the geometry (initial/basic/rough) for all of these engines in place; nearly done with all that I had listed for the initial set. Going to finish the rough geometry pass for the engines, and then figure out the mounting bit. Hope to move onto the mount geometry perhaps tomorrow, and then onto initial plugin stuff wed/thurs/fri. Aiming to have a decent set of parts(all untextured) to test this weekend for concept development and make sure things are going to work out appropriately.

Here are the J2 and J2X engines (WIP):

J2

J2-X

And first pass at an initial mount setup (will not be keeping this exact geometry, was just playing around seeing how to do them / what they would look like)

[JoseEduardo]

an customizable engine mount like the S-II and S-IVB would be awesome for heavy upper stages