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

[Shadowmage]

On Tuesday, March 15, 2016 at 3:07 PM, stratochief66 said:

Thanks for the RO pull request @Shadowmage, it worked very well

On the topic of cutting down part count, it would be nice to have a fuel tank that could be converted to a habitat in flight, after the fuel has been drained or used. For example, the Skylab was originally conceptualized using this 'wet workshop' concept. Since you are in the 'early concept dev' stage, I figured this was a good time to mention it as it certainly doesn't seem like a feature that could be thrown in at the end.
 

Glad that stuff worked out well for you.  There is still a load of improvements and new variants that could be done with the MSRBs, just hoping that the few that I did up work as a good enough example

Will consider a fuel->hab conversion;  I'm honestly not sure if you can alter the crew-capacity of a part at run-time...it is one of the first things I'll be investigating when I start working on the station stuff.

On Tuesday, March 15, 2016 at 5:29 PM, MatttheCzar said:

My mistake, Service Module.  If you could make its lenth extendable, users could have it short for in low kerbin orbit, or even longer for long range missions.

EDIT: 100th page maker!

The problem is the way the model is created;  you can't just 'make it shorter' (or longer), it would require that fully new modeling and texturing be done for the different lengths.  Non-trivial to do.

But anyhow, I am planning a series/set/possibly single part for a modular-service-module setup.  It likely won't be Apollo styled, but it will have options for longer/shorter/different bay options.  Wouldn't expect anything on these until after 1.1 though; will likely be done as I'm conceptualizing the station stuff.

[Shadowmage]

9 hours ago, Sudragon said:

Persistence. That makes it sound like there was a sledgehammer involved. And possibly swearing.

Yes, both   The sledgehammer being proverbial.. the swearing being quite literal.

 

 

[Jimbodiah]

Skylab was not a fuel tank converted into a hab while in space, it was an old tank Saturn 3rd stage tank converted on the ground into a lab and then launched on top of a Saturn V. I don't see converting tanks into habs in mid flight as anything realistic or desirable. I'd rather see actual station parts with habs (like Cx) than converting shipcore tanks into habs.

[Shadowmage]

9 hours ago, Agathorn said:

Hi @Shadowmage

I really like SSTU and was wondering if you might welcome some help?  I am very keen on getting the probe/satellite parts working and instead of just bugging you on it thought it would be more beneficial to offer to help

I can do pretty much everything, modeling, texturing, and coding, I would just need some help understanding how you have things set up for this amazing modular/procedural stuff

If you feel you have the time and will to make contributions, I'm more than open to some collaboration.

The first place to start on all of the modular stuff is... modeling .  Very few of my parts use actual procedural mesh generation; most of the parts are made modular by swapping in and out pre-compiled models, and adjusting stats accordingly.  So... need some models to swap between to get started.  For probe cores this would likely start as a set of probe bodies (a few sizes if not using scaling, possible variants as well), perhaps some trasmitters and dishes/antennas, solar-panels/generators, possibly some experiment/science bits.  Oh, and they would all need to be modeled in such a manner that some of the models can be swapped out without disrupting the overall look or layout;  so your probe bodies would likely want a few 'attachment points' for the swappable bits, possibly different sized attach-points for different classes of attachment.  It is / will be a -very- similar setup to most sci-fi-ship based games;  start with a basic hull with 'hardpoints' that get filled with various goodies.  And...thats about all the concept work I've done for that stuff so far

From there it would need the custom module work to link it all together, position the models, scale stuff (if needed), and do the module-swapping for any modular bits that need special code to drive them (e.g. for the antennas, science experiments).  It would be a few weeks before I could do much regarding the probe-core stuff (though would likely take that long to get the first batch of models created).  The probe cores (and stations/bases/service modules/rovers) are all going to need module-switching capability, which I've not yet written the code for (and don't plan on starting until the 1.1 update is finished).

If this all sounds good to you, feel free to shoot me a PM when you have time and we can start going over more details.

7 minutes ago, Jimbodiah said:

Skylab was not a fuel tank converted into a hab while in space, it was an old tank Saturn 3rd stage tank converted on the ground into a lab and then launched on top of a Saturn V. I don't see converting tanks into habs in mid flight as anything realistic or desirable. I'd rather see actual station parts with habs (like Cx) than converting shipcore tanks into habs.

To be fair, I wouldn't allow converting of the existing MFT tanks;  It would be more of a special segment/module on a station part that could optionally be filled with fuel at launch and had a button to 'convert' it once the fuel was used.

But no, not the highest priority on my list, but as I'll already be mucking about with most of the other related functions, will be easy enough to include this if it is possible.  Still not sure if it will be though (run-time crew capacity changes... unknown...)

[tater]

19 minutes ago, Jimbodiah said:

Skylab was not a fuel tank converted into a hab while in space, it was an old tank Saturn 3rd stage tank converted on the ground into a lab and then launched on top of a Saturn V. I don't see converting tanks into habs in mid flight as anything realistic or desirable. I'd rather see actual station parts with habs (like Cx) than converting shipcore tanks into habs.

I could see having a "variant" of a tank part that is in fact a habitat, but that button should only exist in the VAB, and would then make the part purely structural, with no fuel (some volume could be reserved for EC/monoprop/supplies, however). So you'd make Skylab from a tank in the VAB, you'd not use the fuel, then turn it to a habitat.

[Jimbodiah]

On that topic...  I regularly use WildBlue DSEV which has tanks that allow in-game switching of the contents. I've not seen this ability on any other mod and is super cool to use as you can convert it from one thing to another (you lose all contents of course and start with an empty tank when you switch). This kind of functionality would be super to have in stations/landers as it means you do not need a separate lander for each resource or a space station that can not store Resource B because it has a Resource A and C tank only. The tanks all refer to a cfg file with the resource and amount/volume ratio, so you don't need a separate config for each tank size, and allows you to add additional resources on your own by just adding a cfg file.

 

 

[Shadowmage]

As I understand the original 'wet workshop' plans though -- they were intended to use a... used.. fuel tank for the main hab section.  Hence the 'wet' part of the name... all of the equipment would be inserted into the tank on the ground, and then fuel filled into any remaining volume, and an airlock/hatch added at one end.  After the fuel was depleted, the hatch would be breached, trace fuel vented, life-support machinery brought in / brought online, and the tank would eventually be re-pressurized and used as a station segment.

This is in contrast to the 'dry workshop' which is how Skylab was one -- outfit it on the ground, fit it to a rocket, and launch/orbit it.  Really no reason why the 'dry workshop' needed to be made out of a fuel tank... and seems like they could have done a much better station in general with some custom-built hardware.

4 minutes ago, Jimbodiah said:

On that topic...  I regularly use WildBlue DSEV which has tanks that allow in-game switching of the contents. I've not seen this ability on any other mod and is super cool to use as you can convert it from one thing to another (you lose all contents of course and start with an empty tank when you switch). This kind of functionality would be super to have in stations/landers as it means you do not need a separate lander for each resource or a space station that can not store Resource B because it has a Resource A and C tank only. The tanks all refer to a cfg file with the resource and amount/volume ratio, so you don't need a separate config for each tank size, and allows you to add additional resources on your own by just adding a cfg file.

 

 

The MFT-s already have this functionality (in code anyway) -- it is just disabled on the in-game parts as nobody ever volunteered to test it.

[komodo]

Skylab was a case of "if we want to do it, we have to do it with what we got before they wise up and cut even more of the funding" sort of thing, if I recall. So, basically like many other aerospace projects ><

[Jimbodiah]

From what I read, it was due to costs that they used the spare fuel tank of the Saturn V for skylab.  ^ what he said.

Mage, can you implement it, I can test, never knew you made that functionality.

Edited March 17, 2016 by Jimbodiah

[Shadowmage]

30 minutes ago, Jimbodiah said:

From what I read, it was due to costs that they used the spare fuel tank of the Saturn V for skylab.  ^ what he said.

Mage, can you implement it, I can test, never knew you made that functionality.

 

Drop the following patch somewhere in your gamedata to enable the feature:

Note -- it has had zero testing... might not function at all... let me know what you find out though and I can possibly do some fixing on it tonight.

@PART[SSTU_ShipCore_MFT-A]:FOR[SSTU]
{
	@MODULE[SSTUModularFuelTank]
	{
		%canChangeInFlight = true
	}
}
@PART[SSTU_ShipCore_MFT-B]:FOR[SSTU]
{
	@MODULE[SSTUModularFuelTank]
	{
		%canChangeInFlight = true
	}
}
@PART[SSTU-SC-TANK-MFT-D]:FOR[SSTU]
{
	@MODULE[SSTUModularFuelTank]
	{
		%canChangeInFlight = true
	}
}

One quirk that it might have, depending on fuels being switched, is that it will also change the fuel-tanks dry mass... which is not exactly realistic while in-flight.  Not sure of any way to fix that while still allowing for different dry-mass fractions for different fuels though.

 

Edit:  Fixed patch code to remove the RealFuels/RO NEEDS block.

Further Edit:  You'll need to hit the 'jettison fuel' button before you can switch fuel types, or otherwise make sure that the tank is completely empty.

Edited March 17, 2016 by Shadowmage

[Jimbodiah]

I just added the fuel switch and seems to work so far (can jetisson and change fuel type).

[Jimbodiah]

Will there be a second stage engine that is smaller than the RL10A3? I am using the single LC engine and tweakscaled stock engines for small builds right now as the RL10A3 is way too big (bigger than the tank on 0.625 builds) and can not be scaled down with tweakscale.

[RedParadize]

I have noted something, its more a balance issues than a bug, the MUS-CB is 1/3 the weight of regular tanks for equal volume. Is there a field somewhere to ajust this ?

Edit: My bad, didn't had the same fuel loaded...

Edited March 17, 2016 by RedParadize

[01010101lzy]

22 hours ago, Shadowmage said:

Glad that stuff worked out well for you.  There is still a load of improvements and new variants that could be done with the MSRBs, just hoping that the few that I did up work as a good enough example

Will consider a fuel->hab conversion;  I'm honestly not sure if you can alter the crew-capacity of a part at run-time...it is one of the first things I'll be investigating when I start working on the station stuff.

Maybe @HoneyFox's Tweakable Parameters' code could help you with this.

[Shadowmage]

1 hour ago, 01010101lzy said:

Maybe @HoneyFox's Tweakable Parameters' code could help you with this.

Haven't seen that one before, but I'll take a look over it.  If it allows adjusting of crew capacity, then it must be possible in some fashion (at least the capacity; still no idea on IVAs).  Thanks for the link

 

15 hours ago, RedParadize said:

I have noted something, its more a balance issues than a bug, the MUS-CB is 1/3 the weight of regular tanks for equal volume. Is there a field somewhere to ajust this ?

Edit: My bad, didn't had the same fuel loaded...

 

Please do let me know when you spot stuff like that though, as those are precisely the kind of oddities and balance issues that I need to get cleaned up.

 

20 hours ago, Jimbodiah said:

Will there be a second stage engine that is smaller than the RL10A3? I am using the single LC engine and tweakscaled stock engines for small builds right now as the RL10A3 is way too big (bigger than the tank on 0.625 builds) and can not be scaled down with tweakscale.

Hmm..yes, but they would be more like 'thrusters' and less of an engine, and certainly not LH2 powered; most that I can think of are hypergolic (LMAE, LMDE, Kestrel, AJ10-118? and others).  Would also have less thrust than the RL10 for most of them.

I honestly don't have anything that small on my engine spec sheet; though I'll start looking for candidates - will be needing some smaller engines/thrusters for the probe/satellite-core stuff.

I've personally been using the AJ10-190 for my shuttle-payload-testing probes; but yes, it is a bit oversized for a 0.625m tank.  It fits fine (attachment wise), but the bell is larger than the tank, and it still has about 2x the thrust it needs (TWR >= 1.5; could be far less then half of that).

[Jimbodiah]

Thrust of 5-10kN is fine I think, when scaled down the stock engines don't have much more either and the stage is pretty light anyway.

Is there a way to scale down an existing engine in terms of the model itself? ie make  1/2 or 1/4 scale copy?

[Shadowmage]

11 minutes ago, Jimbodiah said:

Thrust of 5-10kN is fine I think, when scaled down the stock engines don't have much more either and the stage is pretty light anyway.

Is there a way to scale down an existing engine in terms of the model itself? ie make  1/2 or 1/4 scale copy?

Yes -- examine the NRV engine clusters;  in the engine-cluster module there is an 'engineScale' field.  Just set that to your desired scale percent (e.g. 0.5 = 50%), and it will handle the rest of the positioning stuff.  (The H-1 used this as well until recently, as re-used the F1B model scaled to 46%).

So... potentially I could rescale the AJ10's for use as LMDE/LMAE and/or some other upper-stage thrusters.

Lunar Module Ascent Engine = 0.55m diameter, ~6kn thrust, will weight very little (MONO)

Kestrel - ?? diameter, ~12kn thrust, <0.1t mass (KLOX)

Lunar Module Descent Engine = ~.9m diameter, ~18kn thrust, <0.2t mass (MONO)

 

And apparently the LMDE has been repurposed for other uses in real life as an upper-stage thruster : https://en.wikipedia.org/wiki/TR-201  so this is not at all out of the realm of reality.

[Jimbodiah]

Thanks!!! Will try it out and let you know what monsters I've created.

[Shadowmage]

Well, I must say... those crazy Russians sure do know how to make convoluted rocket engines...  but I think I have this one figured out... mostly.  If it all looks like a giant jumble of lines/struts/etc... well.. yeah.  Looks like that to me too, and I kinda know what I'm looking at  

Still need to add in the GG and hook it into the turbo (input fuel, output gas), and clean up the chamber tops and LOX input lines a bit... but geometry is making good progress.  Certainly won't have it for this weekend, but perhaps for next.  Going to be another fairly high-poly model... (~15k tris), but that is mostly unavoidable with the multi-chambered engines... they just have more geometry to them.  The Russian strutting doesn't do any favors to poly count either...but oh-well.  My PC has no problem with a few -million- tris... so it won't even notice having a few tens of thousands on the engine models.

[Shadowmage]

And, as there have been a few requests:

Black and gray lifter mounts; gray and white upper-stage mounts.  Enjoy

[MrMeeb]

13 minutes ago, Shadowmage said:

And, as there have been a few requests:

Black and gray lifter mounts; gray and white upper-stage mounts.  Enjoy

Excellent! Thanks a bunch  

[JoseEduardo]

I like the possibilities....

[Jimbodiah]

No pink? 

[Jimbodiah]

BTW: I made a J2X and AJ10-137 in 1/4 scale and adjusted the weight/thrusts (7-8kN is perfect for 0.5-0.6 TWR). Looks kind of neat too, with the longer vacuum bells. Now to reduce the monstrous flame FX which are still original

[Pappystein]

11 hours ago, Shadowmage said:

Hmm..yes, but they would be more like 'thrusters' and

less of an engine, and certainly not LH2 powered; most that I can think of are hypergolic (LMAE, LMDE, Kestrel, AJ10-118? and others).  Would also have less thrust than the RL10 for most of them.

I honestly don't have anything that small on my engine spec sheet; though I'll start looking for candidates - will be needing some smaller engines/thrusters for the probe/satellite-core stuff.

I've personally been using the AJ10-190 for my shuttle-payload-testing probes; but yes, it is a bit oversized for a 0.625m tank.  It fits fine (attachment wise), but the bell is larger than the tank, and it still has about 2x the thrust it needs (TWR >= 1.5; could be far less then half of that).

The Lockheed/Bell Agena engine family would fit well.  Most of the later Agena probe cores had a tank that narrowed down to the rocket bell from stock size (in case of KSP from 1.25 down to 0.625)   The Agena-D engine would have most of it's motive components buried in the tail of the fuel tank anyway...  https://en.wikipedia.org/wiki/RM-81_Agena

Lots of pictures on the Wikipedia link showing the various Agena configs.   On the Agena Target (for Gemini) the smaller section between the fuel tank and the smaller yet Bell Rocket is the Mono Tanks and lower assembly RCS thruster block (with additional forward thrusters to assist fine maneuvering.)

Also Agena is great for making early satellites out of... After all it was the CORE of several early Recon Sats as well as other Sats!