What is the Kármán line that Blue Origin's all-female crew crossed?

Blue Origin successfully launched six women over the Kármán line Monday morning, marking the first all-female spaceflight since Soviet-era cosmonaut Valentina Tereshkova flew into space on a solo mission in 1963.

The astronauts who crewed the spacecraft - American singer Katy Perry, journalists Gayle King and Lauren Sanchez, former NASA scientist Aisha Bowe, civil rights activist Amanda Nguyen and film producer Kerianne Flynn - experienced several minutes of weightlessness during the trip, which landed about 11 minutes after launch from western Texas.

How far did the crew members get?

Blue Origin's New Shepard rocket propelled the women nearly 106 kilometers above the atmosphere, according to Jeff Bezos' agency. That means they surpassed the Kármán line, a boundary 100 kilometers (about 62 miles) above Earth.

The Kármán line is recognized as the boundary between Earth's atmosphere and space by the International Aeronautical Federation, a Swiss-based governing and registration body. For years, Blue Origin has also said that the Kármán line is the threshold separating Earth's atmosphere from space.

Where does space really begin?

Although it is a discussion of various space agencies, astronauts and researchers, the boundary between Earth and "space" is not clearly defined.

Astrophysicist Jonathan McDowell has proposed that the boundary should be lower, at about 80 kilometers high, arguing that satellites can survive certain elliptical orbits descending to this altitude. However, NASA heliophysicist Doug Rowland stated that it is difficult to delineate where "space" begins, since the Earth's atmosphere does not necessarily stop at a single point, but "simply becomes less and less dense as you go up."

The National Oceanic and Atmospheric Administration (NOAA) claims for its part that a spacecraft would have to travel 600 miles above Earth to completely escape the planet's atmosphere, meaning that the International Space Station (which orbits between 205 and 270 miles above Earth) would not even be considered to be in "space" proper.

Terminology aside, Blue Origin and its new astronauts certainly consider their journey into space, though some may not define it that way, to have been a success.