parts [1.10.x] SDHI Service Module System (V4.0.4 / 11 October 2020)

[Kerbas_ad_astra]

I don't use SDHI anymore, so I'm not too concerned about what revisions finally get made (though I would balk at tinkering with the masses of stock parts, since that will interfere with the literal balancing of vehicles which use the Mk1-2 pod, and throw off the game balancing of mod capsules that use the Mk1-2 as a baseline), but since it's the last two-thirds (i.e. y = 0 to -0.8) of the service module which are dominated by the tanks, -0.4 may be a better CM location, or maybe even -0.6 or further, because the engine will be there to "pad out" the structure (though making the CM too far back may hamper the utility of the service module for less orthodox constructions).

In the end, I habitually put RCS thrusters on all of my capsules anyway (the sides are clear of windows and hatches on most pods), so I'm not really bothered by the exact balance of my service modules. Here's an example (though this particular craft was built to test SMURFF, which cuts the masses of command pods and heat shields in half across the board):

Spoiler

Incidentally, when SMURFF cuts command pod and heat shield masses in half, the heat dissipation of the heat shield (pyrolysisLossFactor) has to be doubled, so that the shield can still reject the same total amount of energy, so bear that in mind if you're going to make the SDHI heat shield lighter (and give it less ablator).

 

[StevieC]

Interesting. Now to switch the Mk 1-2 pod's mass back to stock and try the CoM offset changes to the service module.

[Starwaster]

3 hours ago, StevieC said:

Here is the result with my test of switching the service module back to weigh 1.1 tons dry, and shaving 1.7 tons off the mass of the command module.

Centr of Mass is still a little bit too far forward (don't worry about the torque shown in KER, that's a result of the instruments and such I attached to the sides of the service  module.

I don't think that bottom set of RCS is helping though

What pack are those RCS parts from?

Edited February 11, 2016 by Starwaster
RCS question

[StevieC]

Doesn't matter 'cuz I found a better setup, keeping the Command module at stock mass of 4 tons dry, implementing Kerbas ad Astra's suggestion to keep the service module's mass at 1.1 tons but shift its center-of-mass from -0.2 to -0.6, and using these instead. nertea's Near Future Spacecraft Components gave me the ones on the service module. The ones attached to the docking port are from RLA StockAlike

[sumghai]

So, change SM CoMoffset to -0.6?

[StevieC]

yep. do that and it'll be perfect.

[sumghai]

if @Starwaster and @Kerbas_ad_astra are okay with that tweak, I can push it to the repo within ten minutes.

[StevieC]

57 minutes ago, Starwaster said:

I don't think that bottom set of RCS is helping though

What pack are those RCS parts from?

In my earlier post with the findings of changing the stock Mk 1-2 pod's mass, that bottom set of RCS is from the RLA Stockalike Pack, the upper ones are from Nertea's Near Future Spacecraft Parts pack. In my most recent post, they're all from the RLA Stockalike Pack

Edited February 11, 2016 by StevieC
clarifying

[Starwaster]

@sumghai CoMOffset sounds good if that works. That was next on my list of things to try but busy at the cat sanctuary

On another note, does anyone else here have trouble with the new forum and Chrome where you quote someone, reply to them, and then later, try to quote something else and the previously quoted message shows up instead plus a draft of anything you might have posted previously in response to said old quote??? It's driving me up the wall

[sumghai]

13 minutes ago, Starwaster said:

@sumghai CoMOffset sounds good if that works. That was next on my list of things to try but busy at the cat sanctuary

Sounds good - pushing to repo in five minutes. Good thing I won't need to rewrite the release notes for tomorrow

13 minutes ago, Starwaster said:

On another note, does anyone else here have trouble with the new forum and Chrome where you quote someone, reply to them, and then later, try to quote something else and the previously quoted message shows up instead plus a draft of anything you might have posted previously in response to said old quote??? It's driving me up the wall

I've noticed something similar in Firefox as well - I usually draft my posts elsewhere anyway as a workaround.

EDIT: Okay @StevieC, I've updated my repo - please redownload and check if it works to your satisfaction.

[Starwaster]

@sumghai

not when it started but the heat shield completely depletes its ablator

you might want to compare configs with stock shields which (now) behave more like SDHI used to

Edited February 11, 2016 by Starwaster

[sumghai]

37 minutes ago, Starwaster said:

@sumghai

not when it started but the heat shield completely depletes its ablator

you might want to compare configs with stock shields which (now) behave more like SDHI used to

Investigating now - at work, so don't have a copy of the stock 2.5m heat shield config for 1.0.5. I'm not sure if it's any different to the 1.0.4 version on the KSP wiki, either.

If I am to hazard a guess, my heat shield has a lower mass than stock (0.45 vs 0.5) and a higher pyrolysisLossFactor (900 vs 600), and I believe you were the last person to make those tweaks in my repo. Other than that, all other values are the same as stock.

[Starwaster]

8 minutes ago, sumghai said:

Investigating now - at work, so don't have a copy of the stock 2.5m heat shield config for 1.0.5. I'm not sure if it's any different to the 1.0.4 version on the KSP wiki, either.

If I am to hazard a guess, my heat shield has a lower mass than stock (0.45 vs 0.5) and a higher pyrolysisLossFactor (900 vs 600), and I believe you were the last person to make those tweaks in my repo. Other than that, all other values are the same as stock.

Hrmmm very last change I submitted was to aerodynamics. Last thermodynamics change I did was back in June. KSP shield behavior changed in either 1.0.4 or 1.0.5 (I forget which) which is why the shield is depleting so fast I guess.

The question is, why am I only just now seeing it? Might be because I'm testing in a mostly stock environment. No DRE so no patches being applied. Anyway, I'll push some changes to you to make it behave more like it used to.

[sumghai]

2 minutes ago, Starwaster said:

Hrmmm very last change I submitted was to aerodynamics. Last thermodynamics change I did was back in June. KSP shield behavior changed in either 1.0.4 or 1.0.5 (I forget which) which is why the shield is depleting so fast I guess.

Yep, inprecise statement on my part. My bad.

2 minutes ago, Starwaster said:

The question is, why am I only just now seeing it? Might be because I'm testing in a mostly stock environment. No DRE so no patches being applied. Anyway, I'll push some changes to you to make it behave more like it used to.

I saw this in stock as well, although I initially chalked it up to an overly shallow reentry trajectory.

Tweaks are much appreciated, as always.

 

[StevieC]

Small request. Can you build a few small solid-fueled retro-rockets into the "SDHI Service Module Adaptor" to propel whatever stage we're jettisoning away from the command and service modules? Nothing too big, just asking enough to nudge the circularizing stage of a low-kerbin orbit booster back down to a sub-orbital trajectory, so something similar to the solid-fueled engines built into the command-module fairing that protects it from the escape tower's exhaust plumes?

[sumghai]

32 minutes ago, StevieC said:

Small request. Can you build a few small solid-fueled retro-rockets into the "SDHI Service Module Adaptor" to propel whatever stage we're jettisoning away from the command and service modules? Nothing too big, just asking enough to nudge the circularizing stage of a low-kerbin orbit booster back down to a sub-orbital trajectory, so something similar to the solid-fueled engines built into the command-module fairing that protects it from the escape tower's exhaust plumes?

I'll have to pass on this one, I'm afraid - the adaptor is, for the most part, just a regular staging decoupler with minor allowances for side fairing petals.

[StevieC]

Stock heat-shield numbers are:

800 units of ablator standard supply (it's also the max amount of ablator  that you can have on a 2.5m stock heat-shield)

lossExp= -7500

lossConst = 0.1

pyrolysisLossFactor = 6000

reentryConductivity = 0.01

ablationTempThresh = 500

Not sure if those numbers are of any help to you in figuring out what makes a good heat-shield but that's the stock heat-shield numbers and it holds up decently enough. Haven't gotten to testing the heat-shield yet, myself. Been testing the launch escape system. Will be launching my capsule with service module into orbit shortly and then trying re-entry.

Will edit this post to include my results with the heat-shield numbers that sumghai put into this pre-release build.

[Starwaster]

1 minute ago, StevieC said:

Stock heat-shield numbers are:

800 units of ablator standard supply (it's also the max amount of ablator  that you can have on a 2.5m stock heat-shield)

lossExp= -7500

lossConst = 0.1

pyrolysisLossFactor = 6000

reentryConductivity = 0.01

ablationTempThresh = 500

Not sure if those numbers are of any help to you in figuring out what makes a good heat-shield but that's the stock heat-shield numbers and it holds up decently enough. Haven't gotten to testing the heat-shield yet, myself. Been testing the launch escape system. Will be launching my capsule with service module into orbit shortly and then trying re-entry.

Will edit this post to include my results with the heat-shield numbers that sumghai put into this pre-release build.

I already pushed the part changes to Sumghai on Github

[sumghai]

9 minutes ago, Starwaster said:

I already pushed the part changes to Sumghai on Github

Haven't seen them come through yet, will check back in ten minutes.

[StevieC]

One other small thing that'd be appreciated is if you could put something in the Parachute Clamp-o-tron to detect this addon and put its main feature on that model when detected.

 

[sumghai]

5 minutes ago, StevieC said:

One other small thing that'd be appreciated is if you could put something in the Parachute Clamp-o-tron to detect this addon and put its main feature on that model when detected.

 

I'll have to revisit that after KSP 1.1 comes out - in the meantime, feel free to open up a new issue on GitHub for this request.

[StevieC]

S'okay. I manually tweak the parachute-equipped clamp-o-tron's .cfg file to add the docking target in my installation. The part that I don't know how to add is the conditionals that would automate the detection of the docking-target addon to determine whether to try to render the model for it. I'll make do for now with my manual tweak.

[sumghai]

6 minutes ago, StevieC said:

The part that I don't know how to add is the conditionals that would automate the detection of the docking-target addon to determine whether to try to render the model for it.

Conditional MM patches are fairly easy - I've got a few examples in my repo that add features depending on what other mods are installed.

The reason I'm leaving that for the next update is because I need time to check that the patch positions the docking target in the correct position relative to the SDHI version of the Clamp-o-tron.

[StevieC]

From first-hand experience, the target is in the correct position if you just put this in the .cfg file just before the actual model of the docking-port itself, no need to enter any coordinates, it'll already be in the right place.

	MODEL
	{
		model = FederalProductions/Parts/DockingTarget/COAS_Target
		position = 0,0.19,0
		scale = 1,1,1
		rotation = 0,0,0
	}

All it needs is the conditionals to detect the presence or absence of the docking-target plugin.

[Starwaster]

30 minutes ago, sumghai said:

Haven't seen them come through yet, will check back in ten minutes.

Hmmmm. I didn't do it as a pull request; rather as a file edit...

Anyway, question: How do you feel about starting with the LES RCS starting in the disabled state? Downside is that an action group needs to be set up to toggle them, presumably the abort key. On the other hand, the downside of leaving them enabled by default (as they are now) is that they could be used up by the time the player actually has to abort, if his RCS is on.

Edited February 12, 2016 by Starwaster