Kerbal Space Program puts you in charge of a fledgling space agency on the planet Kerbin, where you design, build, and fly rockets using realistic orbital mechanics. The game uses a simplified but accurate Newtonian physics model — you need to understand delta-v budgets, transfer orbits, and staging to reach other planets. With Career, Science, and Sandbox modes, KSP caters to both structured progression and creative engineering. The modding community adds thousands of parts, visual overhauls, and automation tools that extend the game indefinitely.
Picking the right build determines how your experience plays out. These builds are ranked by overall effectiveness — factoring in damage, survivability, gear requirements, and how well they scale into endgame.
Quick Rankings
| Build | Tier | Playstyle | Core Gear |
|---|---|---|---|
| Pilot | S | Sits in the command pod providing stability assist during all maneuvers. | Command Pod, SAS Module, Reaction Wheels |
| Engineer | A | Manages surface base operations, repairs equipment, and operates mining rigs. | ISRU Converter, Drill, Landing Legs, Parachutes |
| Scientist | A | Runs EVA experiments across biomes and processes data in orbital labs. | Mobile Processing Lab, Science experiments, EVA equipment |
| Tourist | C | Sits passively while you fly them to their destination and back safely. | Extra seats in command pods, passenger cabins |
| Rescue Target | B | Fly to the stranded Kerbal, EVA them to your ship or dock, and return to Kerbin. | Extra command seat or docking port, rendezvous-capable craft |
S-Tier: Pilot
Pilots provide SAS hold capabilities at various levels — Level 1 holds prograde/retrograde, Level 3 unlocks maneuver node hold, and Level 5 gives target hold. Without a pilot or probe core with SAS, you can't lock heading during burns. Essential for every crewed mission.
Core Setup
| Slot | Choice | Why |
|---|---|---|
| Primary Equipment | SRB Booster | Solid Rocket Boosters provide massive thrust at low cost but cannot be throttled or shut down once ignited. |
| Core Gear | Command Pod, SAS Module, Reaction Wheels | Maximizes build potential |
| Stat Priority | Experience Level (gained from reaching new celestial bodies) | Optimal scaling |
| Key Mechanic | orbital mechanics | KSP uses patched conic approximation for orbital calculations — you plan maneuver nodes on your orbital path showing prograde, retrograde, normal, anti-normal, radial in, and radial out burns. |
How to Play Pilot
Sits in the command pod providing stability assist during all maneuvers.
Pilots provide SAS hold capabilities at various levels — Level 1 holds prograde/retrograde, Level 3 unlocks maneuver node hold, and Level 5 gives target hold. Without a pilot or probe core with SAS, you can't lock heading during burns. Essential for every crewed mission.
What makes this build work: The synergy between SRB Booster and orbital mechanics creates a gameplay loop that outperforms other options. Core gear like Command Pod, SAS Module, Reaction Wheels amplifies this further.
Pros:
- Highest overall performance
- Clear stat priority (Experience Level (gained from reaching new celestial bodies)) makes gearing straightforward
- Works in all content types
Cons:
- Popular pick, resources may be contested
- Needs specific gear to reach full potential
A-Tier: Engineer
Engineers repack parachutes, repair wheels and landing legs, and boost ISRU drill and converter efficiency. A Level 3 Engineer makes mining operations viable by increasing ore extraction rates. Essential for self-sustaining bases on other planets.
Core Setup
| Slot | Choice | Why |
|---|---|---|
| Primary Equipment | Mainsail Engine | The RE-M3 Mainsail is KSP's workhorse heavy lifter engine with 1,500 kN thrust and 310s vacuum Isp. |
| Core Gear | ISRU Converter, Drill, Landing Legs, Parachutes | Maximizes build potential |
| Stat Priority | Experience Level for ISRU efficiency bonuses | Optimal scaling |
| Key Mechanic | staging | Rockets are built in stages that separate sequentially — typically boosters first, then lower stages, then upper stages. |
How to Play Engineer
Manages surface base operations, repairs equipment, and operates mining rigs.
Engineers repack parachutes, repair wheels and landing legs, and boost ISRU drill and converter efficiency. A Level 3 Engineer makes mining operations viable by increasing ore extraction rates. Essential for self-sustaining bases on other planets.
What makes this build work: The synergy between Mainsail Engine and staging creates a gameplay loop that offers reliable performance. Core gear like ISRU Converter, Drill, Landing Legs, Parachutes amplifies this further.
Pros:
- Most versatile option
- Clear stat priority (Experience Level for ISRU efficiency bonuses) makes gearing straightforward
- Works in all content types
Cons:
- Lower peak damage than S-tier
- Needs specific gear to reach full potential
A-Tier: Scientist
Scientists can reset experiment modules (like Mystery Goo and Science Jr.) for reuse without returning to Kerbin. They also boost lab processing speed in the Mobile Processing Lab. A Level 5 Scientist can reset every experiment, making multi-biome missions far more efficient.
Core Setup
| Slot | Choice | Why |
|---|---|---|
| Primary Equipment | Nuclear Engine | The LV-N Nerv nuclear engine has only 60 kN of thrust but an exceptional 800s vacuum Isp, making it the most fuel-efficient engine for interplanetary transfers. |
| Core Gear | Mobile Processing Lab, Science experiments, EVA equipment | Maximizes build potential |
| Stat Priority | Experience Level for experiment reset capability | Optimal scaling |
| Key Mechanic | delta-v budgets | Delta-v (change in velocity) is the currency of spaceflight in KSP. |
How to Play Scientist
Runs EVA experiments across biomes and processes data in orbital labs.
Scientists can reset experiment modules (like Mystery Goo and Science Jr.) for reuse without returning to Kerbin. They also boost lab processing speed in the Mobile Processing Lab. A Level 5 Scientist can reset every experiment, making multi-biome missions far more efficient.
What makes this build work: The synergy between Nuclear Engine and delta-v budgets creates a gameplay loop that offers reliable performance. Core gear like Mobile Processing Lab, Science experiments, EVA equipment amplifies this further.
Pros:
- Best survivability
- Clear stat priority (Experience Level for experiment reset capability) makes gearing straightforward
- Works in all content types
Cons:
- Slower clear speeds
- Needs specific gear to reach full potential
C-Tier: Tourist
Tourists are contract-generated passengers who can't perform any actions — they just need to visit specified destinations. Tourist contracts pay well but add dead weight to your craft. Useful only for income in Career mode.
Core Setup
| Slot | Choice | Why |
|---|---|---|
| Primary Equipment | Ion Engine | The IX-6315 Dawn ion engine provides incredible 4,200s Isp but only 2 kN of thrust, requiring enormous electricity reserves (xenon gas + solar panels or RTGs). |
| Core Gear | Extra seats in command pods, passenger cabins | Maximizes build potential |
| Stat Priority | None — tourists have no skills | Optimal scaling |
| Key Mechanic | docking | Docking requires matching orbits with a target vessel, then using RCS (Reaction Control System) thrusters for fine approach. |
How to Play Tourist
Sits passively while you fly them to their destination and back safely.
Tourists are contract-generated passengers who can't perform any actions — they just need to visit specified destinations. Tourist contracts pay well but add dead weight to your craft. Useful only for income in Career mode.
What makes this build work: The synergy between Ion Engine and docking creates a gameplay loop that provides a unique approach. Core gear like Extra seats in command pods, passenger cabins amplifies this further.
Pros:
- Strong in group/team content
- Clear stat priority (None — tourists have no skills) makes gearing straightforward
- Excels in its niche
Cons:
- Weaker solo performance
- Requires deep game knowledge
B-Tier: Rescue Target
Rescue contracts place stranded Kerbals in orbit or on surfaces that you must retrieve. Successfully rescued Kerbals join your roster permanently. These missions teach rendezvous and docking skills, and rescued Kerbals often come with experience.
Core Setup
| Slot | Choice | Why |
|---|---|---|
| Primary Equipment | SAS Module | The Advanced Inline Stabilizer provides torque to rotate your craft without using RCS fuel. |
| Core Gear | Extra command seat or docking port, rendezvous-capable craft | Maximizes build potential |
| Stat Priority | Pilot skill for rendezvous maneuvers | Optimal scaling |
| Key Mechanic | science collection | In Career and Science modes, you collect Science points by running experiments (Crew Report, EVA Report, Mystery Goo, Thermometer, etc. |
How to Play Rescue Target
Fly to the stranded Kerbal, EVA them to your ship or dock, and return to Kerbin.
Rescue contracts place stranded Kerbals in orbit or on surfaces that you must retrieve. Successfully rescued Kerbals join your roster permanently. These missions teach rendezvous and docking skills, and rescued Kerbals often come with experience.
What makes this build work: The synergy between SAS Module and science collection creates a gameplay loop that provides a unique approach. Core gear like Extra command seat or docking port, rendezvous-capable craft amplifies this further.
Pros:
- Unique, rewarding playstyle
- Clear stat priority (Pilot skill for rendezvous maneuvers) makes gearing straightforward
- Excels in its niche
Cons:
- High skill floor, punishing when misplayed
- Requires deep game knowledge
Build Progression Path
- Start with Engineer — the most forgiving option for learning the game
- Transition to Pilot once you understand core mechanics and have access to SRB Booster
- Keep a Scientist setup for content that keeps killing you
- Try Rescue Target for a fresh experience once you've mastered the basics
Gearing Tips
- Invest in your primary equipment first — it gives the biggest power spike
- Achieve stable Kerbin orbit (both apoapsis and periapsis above 70km) before attempting the Mun — if you can orbit, you understand 80% of what you need for the whole game.
- Asparagus staging gives 20-30% more delta-v than parallel staging with the same parts by dropping empty mass early while continuing to fuel the center stack.
- Don't spread upgrade resources across multiple builds until endgame
See our tier list for current meta rankings, or the beginner's guide if you're just getting started.
