What is the approximate altitude of the Karman line, commonly used to demarcate space?

What is the approximate altitude of the Karman line, commonly used to demarcate space?

• A. About 100 kilometers
• B. About 200 kilometers
• C. About 50 kilometers
• D. About 600 kilometers

Answer: (A)

The idea being tested is the practical boundary between air travel and space, defined by where the atmosphere becomes too thin for conventional lift and orbital motion becomes the practical way to stay aloft. The Karman line is widely cited at about 100 kilometers because, above that altitude, the air is so thin that generating enough aerodynamic lift to support a vehicle in flight becomes impractical, and achieving orbit requires speeds and conditions that air-based flight can’t provide. It’s a convention rather than a strict physical wall, and some organizations use slightly different cutoffs (often around 80 km or so), but 100 kilometers is the standard reference used in many contexts. Therefore, the approximate altitude used to demarcate space is about 100 kilometers.

The idea being tested is the practical boundary between air travel and space, defined by where the atmosphere becomes too thin for conventional lift and orbital motion becomes the practical way to stay aloft. The Karman line is widely cited at about 100 kilometers because, above that altitude, the air is so thin that generating enough aerodynamic lift to support a vehicle in flight becomes impractical, and achieving orbit requires speeds and conditions that air-based flight can’t provide. It’s a convention rather than a strict physical wall, and some organizations use slightly different cutoffs (often around 80 km or so), but 100 kilometers is the standard reference used in many contexts. Therefore, the approximate altitude used to demarcate space is about 100 kilometers.