Karman line space boundary Upsc

Karman line

  • The Kármán line is an imaginary boundary between Earth’s atmosphere and outer space, set at 100 kilometers (62 miles) above mean sea level.
  • It’s named after Theodore von Kármán, a Hungarian-American physicist who, in the 1930s, analyzed the altitude at which traditional aircraft could no longer effectively fly due to the dwindling density of air.
Karman line space boundary Upsc

Why is it important?

  • It has historical significance, marking the transition from aeronautics (aircraft) to astronautics (spacecraft).
  • It’s used for record-keeping purposes in aviation and spaceflight. For instance, the FAI (Fédération Aéronautique Internationale) recognizes flights exceeding the Kármán line as achieving “spaceflight” status.
  • It helps us understand the gradual change from the denser atmosphere we’re familiar with to the near-vacuum of space.

Is it the real edge of space?

  • Not exactly. The atmosphere doesn’t have a sharp cutoff point. It thins out gradually as you go higher, with trace amounts of particles detectable well beyond the Kármán line.
  • Some scientists argue for different boundaries based on atmospheric properties or the behavior of spacecraft.

Interesting facts:

  • The Kármán line is roughly the altitude where satellites in low Earth orbit travel.
  • Astronauts experience weightlessness above the Kármán line, not because they’re truly “weightless” but because they’re in constant freefall around Earth.
  • Some suborbital flights, like Virgin Galactic’s SpaceShipTwo, briefly reach above the Kármán line, offering passengers a brief taste of spaceflight.
* * All the Notes in this blog, are referred from Tamil Nadu State Board Books and Samacheer Kalvi Books. Kindly check with the original Tamil Nadu state board books and Ncert Books.