Kerbin

Lore & Background

Kerbin is not merely a planet in the Kerbal solar system; it is the story. The Kerbals are a small, curious, slightly reckless species who built their space program from a flat patch of grass beside a modest hangar. The Kerbal Space Center, with its iconic white-and-red buildings and the ever-present launch pad, sits in a relatively temperate region of the planet. From there, generations of Kerbals have stared up at the night sky, watched Mun trace its slow arc, and decided that the stars were not a ceiling but a destination.

The planet's atmosphere is a double-edged sword. On the one hand, it lets aerodynamic vehicles glide, lets heat shields do their work, and gives Kerbals the luxury of breathing without a suit. On the other hand, it means every ascent must fight drag, every re-entry must manage heat, and every orbital maneuver near the atmosphere risks a catastrophic loss of control. Kerbin's gravity, while lower than Earth's in our own world, is still substantial enough that a Kerbal rocket needs to be a marvel of engineering just to reach a stable low orbit.

Culturally, Kerbin is a world of small-town pragmatism meets grand ambition. The Kerbals are not a spacefaring empire; they are a handful of engineers, pilots, and dreamers who keep pushing the envelope because the alternative is to stay on the ground. That tension—between the cozy launch pad and the cold void beyond Mun's orbit—gives Kerbin its narrative heart. It is the place you always come back to, the place that makes the rest of the system feel both possible and terrifying.

In Their Own Story

The launch window was in eleven minutes. Jebediah stood at the edge of the pad, his four arms crossed over his chest, watching the last of the morning sun slip behind the hangar roof. The rocket—his rocket, the one he'd spent three weeks bolting together in the workshop—coughed and ticked as the pre-flight checks ran. Above, the sky was that deep, clean blue that only exists on Kerbin, and beyond it, barely visible, Mun hung like a pale coin.

"You sure about this, Jeb?" his co-pilot asked, not looking up from the checklist.

Jebediah grinned. "I'm sure about the part where we go up. The part where we come back? That's the interesting part."

The engines lit. The ground shuddered. And for the first time in a very long time, the blue-green world of Kerbin began to shrink beneath his boots, and the stars began to grow.

Reader's Guide

Kerbin is the default starting point for every mission, so treat it like the home base you'll return to a hundred times. Mean radius is roughly 600 km, surface gravity sits near 10 m/s², and the atmosphere is a breathable N₂/O₂ mix with sea-level pressure around 101 kPa. Its orbital period around Kerbol is approximately 426 days, giving you a full year to plan before the seasonal geometry shifts.

Notable surface features include the flat KSC region (your launch pad and hangar), broad ocean basins, and mountain ranges that can complicate low-altitude flight paths. Because the Kerbals are native, there is no "first landing" record—every Kerbal has already landed here a thousand times. The real challenge is getting off it.

What makes Kerbin a natural mission target is simple: it's where you start. What makes it a notorious trap is the atmosphere. A poorly timed re-entry, a fuel miscalculation, or a single misaligned thruster can turn a routine landing into a fiery splashdown in the middle of the ocean. Always leave a fuel margin, always check your periapsis, and for the love of the Kerbals, don't fly into the mountains at 2,000 m/s with no altimeter.

Did You Know?

• Kerbin's ~10 m/s² gravity is noticeably lower than Earth's 9.81 m/s² in real-world terms, but in KSP it still demands a substantial delta-v budget to reach a stable low orbit.
• The planet's breathable atmosphere means Kerbals can walk outside without a pressurized suit, a small but important quality-of-life detail that sets it apart from every other body in the system.
• Mun, Kerbin's only major moon, has no atmosphere and a much weaker gravity well, making it the natural first 'deep space' destination for any Kerbal pilot.
• The Kerbal Space Center is situated in a relatively flat, temperate zone, which is why it serves as the universal launch site—no other location on Kerbin has the same combination of accessibility and infrastructure.