Getting Started with Kerbal Space Program Modding

Kerbal Space Program modding is community-managed in a way few other games match. The CKAN mod manager handles dependency resolution like a package manager, the standard mods are open-source collaborative projects, and the community has documented every install path several times over.

This guide walks the standard install with CKAN on the current KSP 1.12.x release.

Step 1 — Install CKAN

CKAN (Comprehensive Kerbal Archive Network) is the community mod manager. Open-source, multi-platform.

Download the latest CKAN executable. Run it. CKAN auto-detects your KSP install (Steam, GOG, or standalone) and creates a profile for it.

Step 2 — Update the mod index

In CKAN: File → Update Repositories. CKAN downloads metadata for every mod tracked by the community. This is a large data set; the first update takes a minute or two.

After update, CKAN shows ~2000+ mods across various filters.

Step 3 — Install your first mods

In CKAN, click any mod's checkbox and Apply Changes. CKAN resolves dependencies (Module Manager, Toolbar, etc.) and downloads everything.

Three near-essential first picks:

• Module Manager — config-patching framework. Most mods depend on it.
• MechJeb — autopilot mod. Optional but transformative for new players who don't want to learn manual orbital mechanics from scratch.
• KER (Kerbal Engineer Redux) — engineering readouts during construction and flight. Tells you delta-V, thrust-to-weight, orbital parameters.

Mark all three, click Apply Changes, let CKAN install.

Step 4 — Launch KSP

Launch normally through Steam or the KSP launcher. The mods load on startup; the main menu shows "Mods loaded" in the bottom-right.

MechJeb adds a button to vessel pods. KER adds readouts to the construction UI. Both are non-intrusive — disable if you don't want them.

Step 5 — Save the mod profile

In CKAN: File → Export Installed Mods. CKAN exports a .ckan file listing every installed mod. Share this file with friends to replicate your mod set, or use it to recover from a clean reinstall.

Step 6 — Optional: Realism modlines

If you've played vanilla KSP and want a substantially harder spaceflight experience:

• Realism Overhaul (RO) — uses real-world rocket dimensions, fuel chemistry, and engine performance.
• Real Solar System (RSS) — replaces Kerbol with the real solar system.
• Realistic Progression One (RP-1) — career mode with real-world space program progression (1950s–2020s).

These are heavy and slow to install. CKAN handles the dependency graph but expect 30+ minutes for the first install.

Common gotchas

• KSP version mismatch. Many mods only support specific KSP versions. CKAN warns; honour the warning. Pin KSP to a working version via Steam's "no auto-update" setting if you have a working mod set.
• Module Manager not installed. Most mods declare it as a dependency; CKAN handles this. Manual installs sometimes miss it.
• Save game broken after removing parts mod. Removing a parts mod from a save that used those parts deletes the vessels using them.
• CKAN says "incompatible with this KSP version". Use the Compatible KSP Versions dropdown in CKAN's settings to widen the version filter — or update to a KSP version that supports the mod.
• MechJeb interface missing. MechJeb attaches to specific pod parts (Command Pod, etc.). Earlier game career stages may not have unlocked the right pod yet.

For KSP 2 modding (which is a separate game with a separate ecosystem), see the KSP 2 guide.