If you launch a rocket from Earth, then space officially starts at the Kármán Line, which is at:

100 km above Earth’s surface

This is the point where the atmosphere becomes extremely thin and airplanes can no longer fly using lift — so we call it the beginning of space.

But important note:

To reach stable orbit (like satellites), 100 km is not enough.

A rocket must go much higher and must gain very high horizontal speed.

Here’s the full breakdown:

How many kilometers to go into space?

Space begins at 100 km

This is called the Kármán Line.

So technically, a rocket becomes a “spacecraft” after crossing 100 km.

How many kilometers needed for orbit?

Low Earth Orbit (LEO) starts around 160–200 km

Example: Space stations, many satellites.

Typical orbits:

• 200–400 km → e.g., International Space Station
• 500–1,200 km → Earth observation satellites
• 36,000 km → Geostationary satellites
• 384,400 km → Moon

But the important thing:
To stay in orbit, the rocket must reach ~28,000 km/hr horizontal speed.

Simple summary

• 100 km → Space starts
• 200 km → Minimum for stable orbit
• 400 km → Space station height
• 36,000 km → TV satellites (geostationary)