[PART] [1.8.0 - 1.12+] ShadowWorks - Stockalike SLS, Delta IV, and More v2.0.5.1 Waterfall Edition [8-11-2021]

[TheShadow1138]

This is a parts pack that adds a stock alike version of the SLS in 5m size as well as a few Space Shuttle specific parts that will allow you to build the Block I SLS with the complete Orion Spacecraft (CM, SM, and LAS), as well as a full Space Shuttle stack with an External Tank and SRBs that are 5m and 2.25m respectively to be in scale with the Mk3 Spaceplane parts.

Note: Delete your old ShadowWorks Install before installing all Updates.

Version 2.0.5.1 Waterfall FX Compatibility

Updated to Version 2.0!!!

A whole lot has changed with this update.  Since it took me so long to motivate myself to finish the Jupiter (DIRECT) and Altair Lander parts, and seeing the progress of a lot of other mods I decided that the mod as a whole could use a facelift.  With the 50th anniversary of Apollo 11 I was inspired to finally finish the Jupiter and Altair, and complete a near total overhaul of the mod.  Nearly every part has been remodeled and retextured, and I have made use of the stock Part Variant module for mesh and texture switching, throttle-based animations to animate the extending nozzle of the RL10B, and the new mapped specular shaders to provide a mirrored Orion capsule.

I have also gone through and properly given most (if not all) parts an alias taken from the ancient Egyptian pantheon.  I figured, you don't see that very often, so why not.  Below is the Change Log for version 2.0, which is extensive, but I may have missed a couple of things.

Changes 2.0.5.1
-------------
* Re-added the Connected Living Spaces compatibility patch after accidentally leaving it out of v2.0.5

Changes 2.0.5
-------------
* Added Waterfall FX compatibility patch - converts all engines and RCS thrusters except for SRBs to Waterfall FX.
* Fixed texture issue with the 5m Amun-Ra (SLS) Fairing.  The texture will now appear correctly in 1.12+.
* Updated the SSMEMount part to use transform-based attachment nodes.

Changes 2.0.4.1
--------------------
* Added Connected Living Space (CLS) Compatibility (will only work if CLS is installed)

Changes 2.0.4
--------------
ISS SAW Fix thanks to @Hachiro
    * Re-exported the ISS SAW (Solar Array Wing) part
        * Now uses a single attachment node (no longer surface attach)
        * PAW text updated for easier readability and more informative operation
        * Deploying the Array plays the full deployment animation once, while the panels won't actually rotate independently and collect sunlight until they are activated.
        * Should remain deployed regardless of a packing/unpacking operation, so no more having to redeploy after the game packs and unpacks the vessel.

Changes 2.0.3
--------------
Hotfix
    * Re-exported the following parts to add a basic flat normal as KSP apparently no longer gracefully ignores no normal map for "Bumped..." shaders.
        * EUS
        * EUSDecoupler
        * ICPS
        * DCSS5m
        * DCSS5mDecoupler
        * DCSS4m
        * DCSS4mDecoupler
        * AresI
        * AresIIU
        * AresIDecoupler
        * Pyrios
        * PyriosNoseCone
    Everything should be back to looking normal.

 

Changes 2.0.2:
------------------------
* DDS texture encoding changed to DXT5 from DXT3, so textures should show up again!

* Removed duplicate TGA textures that have DDS versions in the SRBs folder.

* Removed the SLS Engine Mount as a separate part, as it really isn't needed any longer.

 

Changes 2.0.1:
------------------------
* Altair Landing Legs will now show up in the career tech tree under "advLanding"

 

Changes 2.0:
---------------------
Removed:
    * External Tank Nose Cone
    * External Tank
    * External Tank End Cap
        * These three were replaced with two tanks (see Additions)
    * File:  "_ShadowWorks_RealChutes.cfg" Removed
    * File:  "_ShadowWorks_FSTextureSwitching.cfg" Removed
    * SLS 5m - 3.25 m Adapter (Orion can be attached to the EUS using the SLS 5m Fairing Base No Payload variant.

Additions:
    * MOARdV Avionics Systems compatibility patches adding functioning MFDs and other controls to the Orion and Altair IVAs.  Also adds a camera and docking radar to the NASA Docking System (NDS) 0.9375m docking port.
    * ModulePartVariant:
        * SLS Core Stage
            * Bare Orange Insulation
            * Black and White Painted
        * ICPS Decoupler
            * Bare Orange Insulation
            * Black and White Painted
        * EUS
            * Bare Orange Insulation
            * Black and White Painted
        * EUS Decoupler
            * Bare Orange Insulation
            * Black and White Painted
        * External Tank Liquid Fuel Tank
            * Bare Orange Insulation
            * STS-1 White
            * Jupiter (DIRECT) Liquid Fuel Tank with Engine Mount (Mesh)
        * External Tank Oxidizer Tank
            * Bare Orange Insulation
            * STS-1 White
            * Jupiter (DIRECT) Oxidizer Tank (Mesh)
        * Shuttle Orbiter Radial Decoupler
            * Bare Orange Insulation
            * STS-1 White
        * Orion Pod
            * Mirrored
            * White
            * EFT-1 Black
        * Orion CM Cap
            * Mirrored
            * White
            * EFT-1 Black
        * ICPS
            * ICPS (Mesh)
            * DCSS 5m (Mesh)
        * SLS 5m Fairing Base
            * Orion attach nodes to accommodate the Altair Lander
            * Orion attach nodes for no/small payloads
            * Orion attach nodes for tall payloads
    * Jupiter (DIRECT) Upper Stage Tank
    * Earth Departure Stage Tank
    * Jupiter Upper Stage Engine Mount (6x symmetry)
    * Earth Departure Stage Engine Mount (1 engine & 2 engine variants, uses ModulePartVariant)
    * Earth Departure/Jupiter Upper Stage interstage decoupler
    * Altair Ascent Stage (w/integrated RCS and ascent engine)
    * Altair Decoupler (w/airlock for crew EVA)
    * Altair Descent Stage (w/integrated engines)
    * Altair RCS Quad (rcs quads for the descent stage)
    * Altair Landing Legs (must set to "Gears" Action Group to use the "g" hotkey)
    * SRB Aft Separation Motor (mounts on aft skirt of 4-segment, 5-segment, and Black Paladin SRBs
    * 4m Delta Cryogenic Second Stage
    * 5m Delta Cryogenic Second Stage (ICPS without the Orion adaptor)
    * Delta IV Medium decoupler
    * RL10A
    * Shuttle Orbiter radial decoupler
    * 4-segment/5-segment SRB radial decoupler
    * External Tank Oxidizer tank
    * External Tank Liquid Fuel tank
    * Ares I Payload Fairing Base
    

Updates: (Nearly Complete Overhaul)
    * Orion Launch Abort System was separated into two (2) separate parts, the Abort Motor, and the Jettison Motor.
    * Orion Pod:  Remodeled to add detail.
    * Orion CM Cap:  Remodeled to add detail.
    * Orion Heatshield:  Updated model, given mirrored finish
    * Orion Chutes:  Made into single chute part that is attached to the Orion Pod directly.
    * Orion CM Decopuler:  Remodeled.
    * Orion Service Module:  Remodeled to add detail.  All RCS pods have been integrated with the SM, and attach nodes added for easier attachment of solar panels.
    * Orion Solar Panels:  Added attach node for easier attachment to SM
    * Orion SM Decoupler:  Remodeled to add detail.
    * Orion SM Fairing:  Remodeled to add detail and improve staging of the petals.
    * ICPS:  Remodeled, 5m DCSS is a variant of this part, added flag decals
    * ICPS Decoupler: Remodeled to add detail.
    * SLS Core Stage:  Remodeled to add detail.  Integrated the SLS Engine Mount.
    * Exploration Upper Stage:  Remodeled to add detail.
    * Exploration Upper Stage Decoupler:  Remodeled to add detail.
    * 4-Segment, 5-Segment, and Dark Knight SRBs:  Remodeled to add detail.
    * SRB Nose Cone:  Remodeled to add detail.
    * Pyrios Nose Cone:  Remodeled to add detail.
    * Delta IV CBC:  Remodeled to add detail.
    * RS-68:  Remodeled to add detail.
    * GEM-60:  Remodeled to add detail, and a gimbal-able nozzle.
    * RS-25:  Remodeled to add detail.
    * RL10B:  Remodeled to add detail, and add an extendable nozzle.
    * RL10C:  Remodeled to add detail.
    * F-1B:  Remodeled to add detail.
    * J-2X:  Remodeled to add detail.
    * Pyrios booster:  Remodeled to add detail.
    * Ares I Upper Stage:  Remodeled to add detail.
    * Ares I Adapter:  Remodeled to add detail, added integrated separation motors.
    * 2.5m and 3.75m to Orion Adapters:  Remodeled to add detail.
    * SLS Fairing Base:  Remodeled to add detail.  Added integrated decouplers, 1 for attaching payloads that is not activated by staging, and another for the Orion that is activated by staging the fairing.  Added attach nodes for the Orion SM Fairing.
    * Delta IV Payload Fairing:  Remodeled to add detail.  Added a payload fairing for the 4m DCSS.

NOTE: The 1.25m base of the PMA is a docking port, you do not need to attach a CBM to dock the PMA to other CBMs

Download on SpaceDock:

Also available through CKAN (or so I'm led to believe)

A review of the mod by @jd9921 (Gemini10 Gamers on YouTube)

Osiris Capsule showing off the mirrored finish

Amun-Ra (SLS) Block I

Amun-Ra Block IB

Amun-Ra Block II

Bastet IV Heavy flying EFT-1

Bastet IV Medium

Amunet Space Shuttle Parts

 

Hathor (Jupiter DIRECT)-130

Hathor-246

MOARdV Avionics Systems IVAs for Osiris and Horus

 

Recommended Mods

Bacon Labs Stockalike Ariane and More (Dead link) - I provided the Ariane and Vega launchers for this pack, and it uses a modified version of the Shuttle SRBs from this mod

Tantares Stockalike Soyuz and Mir - a great mod by Beale adding Soviet/Russian spacecraft and launchers

Bluedog Design Bureau - Stockalike Saturn, Apollo, & More - Awesome stockalike historic American spacecraft and launchers 

License:

ShadowWorks is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License

Edited November 8, 2021 by TheShadow1138
Update for Waterfall compatibility

[Doughy]

for the STS, why is 75% of the cost in the boosters and tank? kinda makes it useless as a reusable craft...

edit: i do like this mod tho. just dont understand that one thing.

[TheShadow1138]

for the STS, why is 75% of the cost in the boosters and tank? kinda makes it useless as a reusable craft...

edit: i do like this mod tho. just dont understand that one thing.

I haven't gone through to balance the part costs yet. I edited configs from other parts to get the one I have and I just didn't touch the cost parameters. I'll have a look at them as well as where they fall in the tech tree, that'll probably be the first update. Thanks for pointing that out. Glad you like the mod.

[Fatal_Gam3er]

Wow this cool, Not many stock SLS's on the forums

[drtedastro]

congrat's...

initial WIP was great. Looking forward to crashing, I mean, playing with these...

Cheers.

[plague006]

Hey TheShadow1138, I worked on adding this mod to CKAN and I just want to pass along: subassemblies can't be installed by CKAN because we can't guarantee if there will be a save/what the save's name will be. If you'd like to be sure that people who install via CKAN have access to them, you can put them into the VAB folder and they can be installed that way.

[TheShadow1138]

Hey TheShadow1138, I worked on adding this mod to CKAN and I just want to pass along: subassemblies can't be installed by CKAN because we can't guarantee if there will be a save/what the save's name will be. If you'd like to be sure that people who install via CKAN have access to them, you can put them into the VAB folder and they can be installed that way.

Thanks for letting me know about that, I know practically nothing about CKAN. The first update I do will be a pass over the part costs and tech tree placements, so I'll make that correction when I upload that update.

[AppleDavidJeans]

Wow, I must commend you on finally releasing the first proper SLS mod, after the apparently failed efforts of others (By the way, is the SLS cursed in KSP or what?). >.>

Anyway, even though everything's in place, things could be reworked in the next update, namely:

• Upping the MPCV's on-orbit delta-v. ~300 m/s of delta-v seems rather weak to me for on-orbit operations. 800 to 1200 m/s would be best for this vehicle. The MPCV's Electric Charge could be upped also, probably to 350. I'd like enough EC to last the capsule through a MechJeb-guided re-entry with Smart A.S.S. on, plus it's good for energy-intensive operations.
  
• Brushing up textures. The textures look okay, but they could be rebrushed to make the mod look more lively. Maybe you could recruit a texture artist to help do this. Maybe Tantares Space Technologies's Beale could help out after he returns from his temporary absence from the forums.
  
• Comms on Orion MPCV. Put an antenna somewhere on it so we can transmit science data.
  
• The SLS Block I, with its ICPS in real-life, in its first mission, will send an unmanned MPCV on a circumlunar trajectory in November 2018. I'd like to see the mod's ICPS delta-v upped to make possible a trans-munar injection of the MPCV.
  
• You may also want to consider resizing the whole SLS stack to a 3.75m/2.5m (Launcher/MPCV) version. Why? Because it could be done to accommodate the SDHI-stock 2.5m capsule pack, which some may prefer to use over this mod's MPCV.
  

Hopefully those suggestions will be implemented, and good job on the release.

Edited July 11, 2015 by AppleDavidJeans

[Kerbal01]

This is a lovely mod, works nice in 1.02 ( I know its designed for 1.04, but idc). the capsule aerodynamics are lovely, it flights straight, though the ICPS needs fuel to do TMI.

[TheShadow1138]

1.0.1 Update

This is a tiny update to attempt to balance the part costs and tech tree placements. It is currently live on KerbalStuff.

Changes 1.0.1:

â€â€Ã¢â‚¬â€Ã¢â‚¬â€Ã¢â‚¬â€Ã¢â‚¬â€Ã¢â‚¬â€Ã¢â‚¬â€

* Part cost balance pass, hopefully the cost is a little more reasonable

* Tech Tree balancing, hopefully this also makes a little more sense

* Actually removed the second redundant SSME

* Removed a couple of test files that snuck in under the radar

Wow, I must commend you on finally releasing the first proper SLS mod, after the apparently failed efforts of others (By the way, is the SLS cursed in KSP or what?). >.>

It does seem like the SLS is cursed when it comes to KSP, though I know noonespecial is working on a much higher detailed SLS and is very close to release. He is currently away tending to health issues, but will return.

Upping the MPCV's on-orbit delta-v. ~300 m/s of delta-v seems rather weak to me for on-orbit operations. 800 to 1200 m/s would be best for this vehicle. The MPCV's Electric Charge could be upped also, probably to 350. I'd like enough EC to last the capsule through a MechJeb-guided re-entry with Smart A.S.S. on, plus it's good for energy-intensive operations.

I'll definitely be increasing the MPCV's delta-v, right now I'm thinking 950m/s. I'll also increase the electric charge capacity, I was really guessing with these initial numbers.

Brushing up textures. The textures look okay, but they could be rebrushed to make the mod look more lively. Maybe you could recruit a texture artist to help do this. Maybe Tantares Space Technologies's Beale could help out after he returns from his temporary absence from the forums.

Could you give any specific suggestions? Are there any textures in particular, or all of them?

Comms on Orion MPCV. Put an antenna somewhere on it so we can transmit science data.

I didn't think about this. I was caught up in balancing that I missed this entirely. It'll be in the next update.

You may also want to consider resizing the whole SLS stack to a 3.75m/2.5m (Launcher/MPCV) version. Why? Because it could be done to accommodate the SDHI-stock 2.5m capsule pack, which some may prefer to use over this mod's MPCV.

I'm afraid I won't be scaling down the SLS. This mod started as simply making an External Tank and SRBs that were in scale with the Mk3 Spaceplane parts, which necessitated a 5m External Tank and 2.25m SRBs. Because of this the SLS must start at 5m since it is derived from the External Tank. Then to keep the ICPS and Orion in scale with the 5m Core Stage, they fall in the 3.125m size range.

Thank you for your feedback, it's much appreciated.

This is a lovely mod, works nice in 1.02 ( I know its designed for 1.04, but idc). the capsule aerodynamics are lovely, it flights straight,

Thanks! It was initially tested in 1.0.2 and thankfully nothing broke when I tested in 1.0.4. Glad it's working well for you.

[*]The SLS Block I, with its ICPS in real-life, in its first mission, will send an unmanned MPCV on a circumlunar trajectory in November 2018. I'd like to see the mod's ICPS delta-v upped to make possible a trans-munar injection of the MPCV.

though the ICPS needs fuel to do TMI.

In my testing I was able to perform a free-return flight around the Mün with the SLS. My flight profile was a roll to heads down and pitch to 45º after clearing the launch clamps. After SRB separation I pitch almost to horizontal. I can get to an initial parking orbit of about 120km barely using the ICPS and have over 800m/s of delta-v remaining. There was barely any propellant remaining in the ICPS after I completed the burn. I was trying to get it to that point in my initial balancing because a couple of my initial values were leaving too much propellant in the ICPS after the TMI burn. I'll toy with it some more to give a little more leeway.

[Doughy]

minor issue: SLS contains locked or invalid parts in VAB load (i have all tech nodes unlocked)

[TheShadow1138]

minor issue: SLS contains locked or invalid parts in VAB load (i have all tech nodes unlocked)

I assume you're trying to use it in Career mode. I know in past version of KSP when you installed new parts that had tech nodes defined it would show in the tech tree as numbers in the upper right-hand corner of the associated tech node and you would have to go in and click on those new parts to make them available in the VAB.

As an example, if I added a part that was in Advanced Rocketry even though I had unlocked Heavier Rocketry I would have to go to the tech tree, lick on "Advanced Rocketry" (which would have a "1" in the upper right-hand corner) and click on the new part. it would then be available in the VAB.

If the all parts are showing up in the VAB then I'm not sure what's going on. The only parts in the craft file that are no part of this mod are the stock launch clams, radial decouplers, and the struts. I also haven't tested the parts in a career game, though I don't see why they wouldn't work properly, or the craft file for that matter. The parts should be in the level 5 - 7 tech nodes, and like I said before the nodes should have a number on the icon, so check that and let me know if that's the problem.

[Doughy]

Everything is unlocked. Tried to launch it and it says the part that's missing is 4x Orion SM Solar Panels SW-SP-01 which I can't find anywhere, in VAB or tech tree. They actually are attached to the craft though, but missing from the parts list.

Edited July 12, 2015 by Doughy

[TheShadow1138]

Doughy said:

Everything is unlocked. Tried to launch it and it says the part that's missing is 4x Orion SM Solar Panels SW-SP-01 which I can't find anywhere, in VAB or tech tree. They actually are attached to the craft though, but missing from the parts list.

I'm truly sorry about that. I was just testing it myself and found exactly what your have. The problem is that when I designated the "TechRequired" in the OrionPanels.cfg I named it "highPowerElectrics" when it should be "largeElectrics". There are a couple of other small tweaks to part balancing that I'm going to make and I'm going to upload them tonight (at least by 9:00 PM EDT) along with this fix.

Thank you for finding this, and again my apologies.

Update 1.0.2

With the feedback I've gotten so far I have implemented a couple of changes to performance, and thanks to Doughy I have corrected an issue that kept one from being able to use the included SLS Block I craft file in career mode.

Changes 1.0.2:

-------------------------

* Adjusted RL-10B Isp to give more leeway for TMI burns

* Adjusted OrionSM mass and propellant amounts to get 950m/s of delta-v

* Fixed TechRequired on OrionPanels (was causing the craft to be unusable in career mode)

Edited December 1, 2015 by TheShadow1138

[Doughy]

Awesome thank you!

[AppleDavidJeans]

Could you give any specific suggestions? Are there any textures in particular, or all of them?

I'd say the Orion pod, service module, ICPS are the ones that could be in need for retexturing the most.

Oh I have another suggestion: Give us the Exploration Upper Stage and appropriate adapters please. Here's some pictures of it:

[TheShadow1138]

I'd say the Orion pod, service module, ICPS are the ones that could be in need for retexturing the most.

Are you thinking along the lines of panel lines and rivets being added, or something else? The SM and ICPS are pretty simple from all the images I can find, not much detail, just white.

Oh I have another suggestion: Give us the Exploration Upper Stage and appropriate adapters please. Here's some pictures of it:

http://i.imgur.com/MwfNH81.jpg

http://www.nasaspaceflight.com/wp-content/uploads/2013/11/Z85.jpg

I fully intend to do the Exploration Upper Stage, a cargo fairing plate, and an adapter for the Orion. I am also planning an adapter with a 3.75m base so the Orion can be launched with 3.75m launchers, and perhaps an adapter with a 2.5m base. I have yet to decide how to make the EUS look as there are multiple designs apparently floating around. The image you provided seems to be about the most prevalent design, though NASA's site has a different design, that I was leaning toward, but I haven't nailed down what I want yet.

[Fatal_Gam3er]

Could you add the Ares I from the constellation project? Anyway its a good mod

[TheShadow1138]

Could you add the Ares I from the constellation project? Anyway its a good mod

I have given it consideration as it would really only require at most two parts to be added. I'm going to focus on the EUS, fairings, adapters, and boosters for the Block IB and II SLS first, and then perhaps the Ares I upper stage and one or two other things.

[Fatal_Gam3er]

Woot Thanks man

[plague006]

Hey Shadow, I noticed you moved the Subassemblies folder into VAB. What I actually meant was that the .craft files inside Subassemblies should be dropped into VAB. Essentially we have to treat assemblies like normal ships, and then hope people realize they're not full ships. Sorry for making you jump through hoops like this.

[AppleDavidJeans]

I did some research on the SLS's core stage and ICPS engines, and came up with these ISP Values:

ICPS RL-10B I_sp (Vac): 464 s

ICPS RL-10B I_sp (ASL): ??? s (Either my Google Ninja skills have worn off or NASA intends the ICPS to be used only in a complete vacuum. >.> I'd peg down 373 s as a temporary number though based on the RL-10B2's Wikipedia page.)

Core Stage RS-25 I_sp (Vac): 452 s

Core Stage RS-25 I_sp (ASL): 366 s

You said that you were guessing at numbers for the most part, but assuming that you researched on this, you probably came across these numbers and thought that they needed to be scaled down in KSP for realistic performance. Well, specific impulse is a measure of efficiency, which is a ratio and therefore does not need scaling, plus Kerbin's atmosphere is the same pressure as Earth's at sea level. Plug those numbers into the cfgs and you'll be in for a boon. Using the rocket equation on the ICPS with MPCV attached without shroud or LAS shows that a 464 s RL-10B2 engine yields 2273.45 m/s of delta-v, which is perfect for either TMI or interplanetary injections.

Hope this helped.

[TheShadow1138]

plague006 said:

Hey Shadow, I noticed you moved the Subassemblies folder into VAB. What I actually meant was that the .craft files inside Subassemblies should be dropped into VAB. Essentially we have to treat assemblies like normal ships, and then hope people realize they're not full ships. Sorry for making you jump through hoops like this.

No problem. I understand we have to accommodate the way the program works, so I can correct that quickly enough and get a hot fix out soon. Thanks for telling me about all this, I have no experience with CKAN whatsoever.

AppleDavidJeans said:

I did some research on the SLS's core stage and ICPS engines, and came up with these ISP Values:

ICPS RL-10B I_sp (Vac): 464 s

ICPS RL-10B I_sp (ASL): ??? s (Either my Google Ninja skills have worn off or NASA intends the ICPS to be used only in a complete vacuum. >.> I'd peg down 373 s as a temporary number though based on the RL-10B2's Wikipedia page.)

The RL-10B-2 on the ICPS will only operate in vacuum as it will perform the orbital insertion burn and then the TLI burn, so a sea-level Isp rating would be irrelevant. That's probably why neither you, nor I could find the sea-level Isp.

Quote

Core Stage RS-25 I_sp (Vac): 452 s

Core Stage RS-25 I_sp (ASL): 366 s

You said that you were guessing at numbers for the most part, but assuming that you researched on this, you probably came across these numbers and thought that they needed to be scaled down in KSP for realistic performance. Well, specific impulse is a measure of efficiency, which is a ratio and therefore does not need scaling, plus Kerbin's atmosphere is the same pressure as Earth's at sea level. Plug those numbers into the cfgs and you'll be in for a boon. Using the rocket equation on the ICPS with MPCV attached without shroud or LAS shows that a 464 s RL-10B2 engine yields 2273.45 m/s of delta-v, which is perfect for either TMI or interplanetary injections.

Hope this helped.

When I said I was guessing, I was referring specifically to the Orion SM thrust and Isp values. I did find all the thrust and Isp values for the RL-10B-2, RS-25D, and SRBs as they were much more readily available and I considered them essential to my initial config setups for those parts.

I know that Isp is a measure of the engine's efficiency and can be mathematically defined either as the ratio of effective exhaust velocity to standard acceleration due to gravity (v_e/g_o) or thrust to the product of standard acceleration due to gravity and propellant mass consumption rate (F_thrust/(m_dot*g_o)). You could use the real-world Isp values for the engines in KSP, but doing so would mean that you have to either adjust the thrust or the mass of what that engine has to lift. As as example, when I changed the available ∆v in the MPCV, if I wanted to keep the thrust and mass values the same, the Isp would have ben about 1250 seconds. If I wanted to keep the I_sp, however, the propellant mass would have to increase, and to keep TWR as it was I would have to decrease the dry mass accordingly. I would actually have had to have a negative dry mass to keep I_sp where it was before, which led to a combined increase in I_sp and propellant load and a decrease in dry mass.

The rocket equation is a good way to explain why I didn't use the real-world Isp values. It takes about 9700 m/s of ∆v to get to LEO, but it only takes about 4300 m/s of ∆v to get to LKO, so when scaling down a real-world launcher to KSP, you must scale the amount of ∆v. The LKO ∆v is about 44% that of LEO, so for scaling we could set up an equation thusly:

∆v_LKO = 0.44*∆v_LEO = v_e*ln(M_o/m_f)

Now, if we appropriately scale the masses such that the ratio of M_o/m_f is the same in KSP as it is in real-life, then the only thing we can change to lower the ∆v is v_e. V_e is the effective exhaust velocity and is equal to the product of specific impulse and standard acceleration due to gravity (I_sp*g_o), and since g_o must be constant we must alter the I_sp to scale down the ∆v.

What I did to start balancing was to start with the mass of the orbiter I built in KSP, compared that to the real orbiter's mass, then using the total mass of the real STS stack was able to determine the scaled down mass of the combined ET and SRBs. From there I was able to get the gross mass of the ET and the individual SRBs. Then, to get an appropriate thrust-to-weight ratio at liftoff I determined the total thrust that was needed and divided it among the SSMEs and SRBs. This provided a good TWR that didn't tear the orbiter apart and didn't cause too much heating. The issue this raised was that there was too much propellant remaining in the ET, which further caused a slight issue with TWR after SRB separation. The only ways to correct this would be to alter the masses of the ET and SRBs and adjust the thrusts accordingly, or adjust the SSME I_sp to be less efficient. The latter was a much simpler thing to do, so I decreased the I_sp to consume more propellant.

This then necessarily informed the balancing of the SLS, since it uses Shuttle derived hardware and I would have to use the SSMEs I balanced for the STS to power the Core Stage f the SLS. So, the masses of the SRBs and Core Stage were based on the masses of the ET and Shuttle SRBs to start and then lowered a bit to get the performance needed (getting to a sub-orbital trajectory such that the ICPS only needed to perform the insertion and TMI instead of completing the ascent. I started the RL-10B off with the same I_sp I gave the SSMEs and gave the ICPS a mass in scale with the Core Stage (based on the real-world ratio). This gave the ICPS too much ∆v; it could perform TMI, Munar orbit insertion, and TKI. So, again, ti maintain TWR for the ascent I had to adjust the I_sp of the RL-10B to decrease the amount of ∆v and bring its performance more in line with the actual rocket. I think 2273.45 m/s is rather excessive for TMI. I don't remember ever using anywhere near 1000 m/s to perform TMI. In fact, in my tests with the SLS I never had to use more than 855 m/s to perform the TMI burn for a free-return trajectory.

Are you still having difficulty performing the TMI burn with the ICPS as it is currently? If so I can always bump up the I_sp a little more.

Edited December 1, 2015 by TheShadow1138

[AppleDavidJeans]

No problem. I understand we have to accommodate the way the program works, so I can correct that quickly enough and get a hot fix out soon. Thanks for telling me about all this, I have no experience with CKAN whatsoever.

The RL-10B-2 on the ICPS will only operate in vacuum as it will perform the orbital insertion burn and then the TLI burn, so a sea-level Isp rating would be irrelevant. That's probably why neither you, nor I could find the sea-level Isp.

When I said I was guessing, I was referring specifically to the Orion SM thrust and Isp values. I did find all the thrust and Isp values for the RL-10B-2, RS-25D, and SRBs as they were much more readily available and I considered them essential to my initial config setups for those parts.

I know that Isp is a measure of the engine's efficiency and can be mathematically defined either as the ratio of effective exhaust velocity to standard acceleration due to gravity (v_e/g_o) or thrust to the product of standard acceleration due to gravity and propellant mass consumption rate (F_thrust/(m_dot*g_o)). You could use the real-world Isp values for the engines in KSP, but doing so would mean that you have to either adjust the thrust or the mass of what that engine has to lift. As as example, when I changed the available ∆v in the MPCV, if I wanted to keep the thrust and mass values the same, the Isp would have ben about 1250 seconds. If I wanted to keep the I_sp, however, the propellant mass would have to increase, and to keep TWR as it was I would have to decrease the dry mass accordingly. I would actually have had to have a negative dry mass to keep I_sp where it was before, which led to a combined increase in I_sp and propellant load and a decrease in dry mass.

The rocket equation is a good way to explain why I didn't use the real-world Isp values. It takes about 9700 m/s of ∆v to get to LEO, but it only takes about 4300 m/s of ∆v to get to LKO, so when scaling down a real-world launcher to KSP, you must scale the amount of ∆v. The LKO ∆v is about 44% that of LEO, so for scaling we could set up an equation thusly:

∆v_LKO = 0.44*∆v_LEO = v_e*ln(M_o/m_f)

Now, if we appropriately scale the masses such that the ratio of M_o/m_f is the same in KSP as it is in real-life, then the only thing we can change to lower the ∆v is v_e. V_e is the effective exhaust velocity and is equal to the product of specific impulse and standard acceleration due to gravity (I_sp*g_o), and since g_o must be constant we must alter the I_sp to scale down the ∆v.

What I did to start balancing was to start with the mass of the orbiter I built in KSP, compared that to the real orbiter's mass, then using the total mass of the real STS stack was able to determine the scaled down mass of the combined ET and SRBs. From there I was able to get the gross mass of the ET and the individual SRBs. Then, to get an appropriate thrust-to-weight ratio at liftoff I determined the total thrust that was needed and divided it among the SSMEs and SRBs. This provided a good TWR that didn't tear the orbiter apart and didn't cause too much heating. The issue this raised was that there was too much propellant remaining in the ET, which further caused a slight issue with TWR after SRB separation. The only ways to correct this would be to alter the masses of the ET and SRBs and adjust the thrusts accordingly, or adjust the SSME I_sp to be less efficient. The latter was a much simpler thing to do, so I decreased the I_sp to consume more propellant.

This then necessarily informed the balancing of the SLS, since it uses Shuttle derived hardware and I would have to use the SSMEs I balanced for the STS to power the Core Stage f the SLS. So, the masses of the SRBs and Core Stage were based on the masses of the ET and Shuttle SRBs to start and then lowered a bit to get the performance needed (getting to a sub-orbital trajectory such that the ICPS only needed to perform the insertion and TMI instead of completing the ascent. I started the RL-10B off with the same I_sp I gave the SSMEs and gave the ICPS a mass in scale with the Core Stage (based on the real-world ratio). This gave the ICPS too much ∆v; it could perform TMI, Munar orbit insertion, and TKI. So, again, ti maintain TWR for the ascent I had to adjust the I_sp of the RL-10B to decrease the amount of ∆v and bring its performance more in line with the actual rocket. I think 2273.45 m/s is rather excessive for TMI. I don't remember ever using anywhere near 1000 m/s to perform TMI. In fact, in my tests with the SLS I never had to use more than 855 m/s to perform the TMI burn for a free-return trajectory.

Are you still having difficulty performing the TMI burn with the ICPS as it is currently? If so I can always bump up the I_sp a little more.

Well, I'm using MechJeb. SLS seems to not want to play along with it. If I set a flight profile with the ascent turn indicator, it'll aim high, and it eventually stops pushing the apoapsis before it gets to the intended height (I set 100 km, it's gonna do 80 km. I do 80km, it's gonna do 50-60km), even though it still is thrusting, and it gets to the situation where I'd have to make a periapsis burn in the atmosphere to complete the push to the desired apoapsis, and then I'd have to take a looooooooooong coast out of the atmosphere and to the final circularization burn 180 degrees from the KSC. With my other rockets, they usually behave well with MechJeb. SLS? Not so much. I thought the ISP was the issue, but it apparently seems to not be. Have you tested this with MechJeb?

And did you upload the correct version? Because even though you say you've tweaked the MPCV to have 950 m/s, I'm still getting only 300 m/s. ICPS could still use a bump though.

[TheShadow1138]

Well, I'm using MechJeb. SLS seems to not want to play along with it. If I set a flight profile with the ascent turn indicator, it'll aim high, and it eventually stops pushing the apoapsis before it gets to the intended height (I set 100 km, it's gonna do 80 km. I do 80km, it's gonna do 50-60km), even though it still is thrusting, and it gets to the situation where I'd have to make a periapsis burn in the atmosphere to complete the push to the desired apoapsis, and then I'd have to take a looooooooooong coast out of the atmosphere and to the final circularization burn 180 degrees from the KSC. With my other rockets, they usually behave well with MechJeb. SLS? Not so much. I thought the ISP was the issue, but it apparently seems to not be. Have you tested this with MechJeb?

And did you upload the correct version? Because even though you say you've tweaked the MPCV to have 950 m/s, I'm still getting only 300 m/s. ICPS could still use a bump though.

I didn't test this with MechJeb. I haven't used MechJeb in a game for a while now, though I did use it when I was developing the Ariane and Vega rockets for Bacon Labs to try and balance them, and I used it in my initial testing of my Space Shuttle parts, but it couldn't control it well enough after SRB separation. I considered that not everyone would be using MechJeb and so believed that it would be best to make sure it was flyable without MechJeb believing (apparently erroneously) that if it was flyable by-hand that MechJeb would be able to handle it without checking to see if it could handle either the Shuttle or the SLS.

What altitude do you start your turn? When I fly it manually I pitch over to 45º beginning around 1000m, after rolling to heads-down. I'll install MechJeb again and play around with some values.

I checked the download and it does have the most recent OrionSM.cfg with the changes. To check your install, see if your OrionSM.cfg has the following values:

mass = 0.03

atmosphereCurve
{
  key = 0 495
  key = 1 315
}

RESOURCE
{
 name = LiquidFuel
 amount = 150
 maxAmount = 150
}

RESOURCE
{
 name = Oxidizer
 amount = 184
 maxAmount = 184
}

These numbers were obtained through calculations and so should be correct, unless I made a mistake somewhere, which is possible. I'll double check this to make sure I didn't make a mistake.

I'll bump the I_sp of the RL-10B back to the value I started it in my testing. Thanks for the feedback.

Edited July 13, 2015 by TheShadow1138