Kerbal Space Program
2,277 Mods
Utility and Navigation
Miscellaneous
Science
Parts Pack
Propulsion
Structural and Aerodynamic
Gameplay
Resources
Command and Control
Ship Systems
Sub-Assembly
Physics
Twitch Integration
Near Future Aeronautics
243k DownloadsAdvanced aircraft engines and accessories
Easy Vessel Switch (EVS)
227k DownloadsMakes switching vessels easy and predictable
Community Tech Tree
223k DownloadsExpanded tech tree for KSP
Kerbal Atomics
221k DownloadsAdditional nuclear engines for KSP
Feline Utility Rovers
217k DownloadsThis mod adds part for rovers. It includes also a laboratory and means to create articulated rovers
Firespitter
199k DownloadsPropeller plane and helicopter parts
Cryogenic Engine Pack
197k DownloadsHigh Isp chemical rockets!
MechJeb Embedded Universal
195k DownloadsMechJeb Embedded with ModuleManager it Gives MechJeb Functionality to every command module, even from mods! Version Independent (should be :P) Career mode supported
Far Future Technologies
183k DownloadsOptimistic but generally viable future spacecraft technologies.
HotRockets! Particle FX Replacement
179k DownloadsHotRockets! Release for 1.0.4
Stockalike Station Parts Expansion
163k DownloadsSpace station and surface base parts [just updated with more parts]
USI Kolonization Systems (MKS/OKS)
160k DownloadsOrbital and planetary bases and colonies for KSP!
For Science!
160k DownloadsYour science autopilot.
Realistic Atmospheres
148k DownloadsRemodeled atmospheres for all KSP celestial bodies.
Tarsier Space Technology Continued...
139k DownloadsSpace Telescopes with Galaxies and Rover Chemical analysis
(6S) Service Compartment Tubes (SCT)
138k DownloadsEver wanted to have smooth rockets without putting RCS tanks, batteries, mechjeb and whatnot on the top of the hull? Here’s a solution! And it is only 2 PARTS!!!
Unofficial B9 Aerospace REPACK
134k DownloadsMy "Unofficial" repack of B9 Aerospace that Just Works (TM)
Transfer Window Planner
132k DownloadsAn in-game implementation of AluxMun's Launch Window Planner WebApp - to plan when to make planetary transfers
Lazor System
132k DownloadsLazor System is an advanced targeting and guidance system with a lot of functions bundled in subsystems which can be activated by placing colored lazors on your vessel.
SpaceY Expanded (SYX) by NecroBones
120k DownloadsAn optional add-on for the SpaceY Heavy Lifters parts pack, adding 7.5m parts, engines, and other accesories.