How to assemble & configure a complete SDHI CSM stack
The following guide demonstrates how to assemble and configure a complete Command-Service Module (CSM) stack using the parts included in the SDHI Service Module Systems pack.
Ensure that you have installed the latest version(s) of all the required dependencies.
1) Place a Mk 1-2 Command Pod (from the Pods tab) into the assembly area
2) Right-click on the Mk 1-2 Command Pod and click Install Umbilical Port
The umbilical port is a static model with no actual functionality, but provide a visually-plausible justification for the flow of resources between the pod and the Service Module. This port can be toggled off if you are building a vessel that does not use the Service Module system.
3) Add the SDHI 2.5m Heat Shield (from the Structural tab) to the bottom of the pod
4) Add either the Clamp-O-Tron Docking Port - Parachute version or the IACBM 1.25m - Parachute version (from the Utility tab) to the bottom of the pod
Your choice of docking port depends on what sort of vessels you plan to dock with - the Clamp-O-Tron version is compatible with the classic Clamp-O-Tron docking port from the stock KSP game, while the IACBM used for FusTek Station Parts.
For the purposes of this guide, we're using the Clamp-O-Tron version. Make sure its staging icon (the parachute symbol) is in Stage 0.
5) Add the SDHI 2.5m Service Module (from the Fuel Tanks tab) to the bottom of the stack
Note: If you have MechJeb installed, the Service Module may show up in the staging list as a vertical decoupler - you can safely ignore it as the Service Module decoupler already has its staging functionality disabled. (Alternatively, you can move it to an extra stage between the Command Pod and the engine in the next step)
6) Add the LV-909 Liquid Fuel Engine (from the Engines tab) to the bottom of the stack
By default, stock engines come with fairings that automatically appear when a decoupler or other part is directly stacked beneath it. But since we will be encapsulating the Service Module within its own fairing system, right-click on the engine and disable the shroud.
Make sure that its staging icon (the liquid rocket engine symbol) is in Stage 1.
7) Add the SDHI 2.5m Service Module Adapter (from the Aerodynamics tab) to the bottom of the stack
Make sure that its staging icon (the horizontal decoupler symbol) is in Stage 2.
8) Add solar panels, RCS thrusters, antennae etc. to the recessed ribbed surface of the Service Module
The fairing panels we will add in later steps will protect these from aerodynamic stresses during launch.
Here we're using stock parts; feel free to choose accessories from stock or third-party add-ons that best fit your specific mission requirements.
9) In Action Group editing mode, assign all your solar panels, antennae and any other items you want to deploy in orbit to Custom02
When the Alpha2 key (2 in Windows) is pressed in-flight, this will automatically deploy all of your accessories simultaneously, instead of having to extend/retract them one-by-one.
10) In Action Group editing mode, assign the Service Module's Decouple action to Custom03
When the Alpha3 key (3 in Windows) is pressed in-flight, this will decouple the command pod from the Service Module. This should be reserved for normal / end-of-mission decoupling, as we will be handling abort scenarios separately.
This decoupler was deliberately designed not to be staged, to prevent accidentally leaving a command pod in orbit without a means to deorbit it and bring the crew home safely.
11) In Action Group editing mode, assign the parachute-equipped docking port's Arm parachute action to Custom04
When the Alpha4 key (4 in Windows) is pressed in-flight, this will arm the drogue-mains parachute deployment sequence to automatically activate at an altitude of 12.5km.
12) Add the SDHI 2.5m Service Module Fairings (from the Aerodynamic tab) to the floating "helper" attach nodes on the Service Module
Make sure that their staging icons (the vertical decoupler symbols) are in Stage 3, as the fairings need to be jettisoned before the CSM stack separates from the rest of your lifter rocket.
TIP: To place the fairings on both sides simultaneously, set your Symmetry Mode to 2x and enable Angle Snap.
13) Add the SDHI Mk1-2 Pod Boost Protective Cover (from the Aerodynamic tab) to the stack node on top of the docking port
The slot cutout in the BPC should be aligned with the umbilical on the Service Module.
Make sure that its staging icon (the horizontal decoupler symbol) is in Stage 4, as during normal flight, the BPC needs to be jettisoned before the side fairings.
14) Add the SDHI Launch Escape System (from the Utility tab), then disable its RCS thrusters via the right-click context menu
We will be reactivating the LES's steering motor RCS thrusters via the Abort action group later, so don't panic.
Make sure that its staging icon (the solid booster rocket symbols) are in Stage 4, as during normal flight, the abort system will be jettisoned along with the BPC.
15) In Action Group editing mode, assign the Boost Protective Cover's Decouple and Activate Engine actions to Custom10
When the Alpha0 key (0 in Windows) is pressed in-flight, the BPC will be jettisoned from the CSM stack.
A couple of things to note:
- It may seem redundant to manually assign an action to jettison the BPC, when it is already going to be staged during normal flight. However, after triggering an emergency abort sequence, it is preferable to be able to discard the BPC with one keypress rather than spamming the spacebar to trigger it via staging.
- By itself, the decoupler on the BPC does not provide sufficient force to push itself away from the Command Pod (stronger decouplers would have destroyed the parachute-equipped docking ports). Hence, a number of miniature solid rocket boosters have been added to the BPC to gently push the cover away from the pod.
16) In Action Group editing mode, assign the Launch Escape System's Activate Engine and Toggle RCS Thrust actions, as well as the Service Module's Decouple action, to Abort
When the Abort key (Backspace in Windows) is pressed in-flight, the Command Pod will be severed from the Service Module and be pulled away by the Launch Escape System. At the same time, the steering motor RCS thrusters on the LES will get reactivated, allowing the Pod to be steered in mid-air during abort.
17) Build the rest of your lifter rocket
TIP: Have your second stage main engine in the same stage as the Boost Protective Cover and the Launch Escape System, so that during normal flight the latter items will be discarded when the second stage engines are first fired.
- Custom02: Deploy solar panels / antennae
- Custom03: Command Pod / Service Module decoupling (normal, end-of-mission)
- Custom04: Arm drogue-mains parachutes
- Custom10: Boost Protective Cover jettison (post-abort)
- Abort: Activate Launch Escape System, LES steering thrusters, Command Pod / Service Module decoupling (emergency)
- If you have access to the Info Popup feature from the Firespitter plugin (e.g. Firespitter's FS3I Info popup, B9 Aerospace's Info Drive), you can add such a part to your vessel and use it to document the aforementioned Action Group settings, as an in-flight manual of sorts.
- If you wish to use the SDHI Heat Shield but do not need a fully-fledged Service Module, or are building your own propulsion trunk out of stock parts, you can use the SDHI 2.5m Avionics Ring (from the Structural tab) instead.
- If you are using a launch clamp as a crew access walkway connected to the Boost Protective Cover on the Command Pod (e.g. FASA Launch Tower) , assign the clamp to the Abort action group, so that in case of an pad abort, the pod can fly clear of the launch pad.
- The flag icon on the Boost Protective Cover can be toggled on or off via the ToggleFlag option in the right-click context menu.
