That’s a question a lot of space geeks have – and, ApparentlyJeff Bezos’ team at Blue Origin cares a lot.
There is no single definition of the term “outer space”. Determining where space begins is largely an exercise in determining exactly where Earth’s atmosphere becomes less disturbed by Earth’s gravity. But there is no exact height where this happens. The atmosphere is weakening, but the “vacuum of space” is never completely devoid of matter. It’s a blurry line.
Where does space begin? Does it start when you look up, and the sky turns from blue to dark and is dotted with stars? What happens when you go so high that you float, as you see with the astronauts on the space station?
Well, astronauts don’t float on the space station because they’re at a very high altitude, because they’re in orbit. Honestly, according to NASA, tighten Our:
A spinning spacecraft is moving at the right speed so that its fall curve matches that of the Earth. Because of this, the spacecraft continues to fall toward Earth but never collides with it. As a result, they fall around the planet. The moon stays in orbit around the earth for the same reason. The moon also falls around the earth.
And while Branson and his crew won’t go into orbit, they will suffer from microgravity, as they fall freely from the height of their flight, much like the experience of astronauts on the International Space Station. Except they’re not moving at over 17,000 miles per hour like the people on the International Space Station, so SpaceShipTwo will scream back to Earth instead of constantly spinning around the planet
But when it comes to sub-orbital flight — AKA flights that don’t accelerate enough to enter Earth’s orbit — Branson and Bezos’ aerospace companies focus on the altitude they reach.
Branson’s flight today is expected to reach more than 50 milesIt is the height that the US government considers the beginning of outer space.
Bezos’ flight on July 20 will reach more than 62 miles – Also known as the Karman Line – the height that is internationally recognized as the limit.
What exactly is correct – the US-accepted 50-mile mark or the internationally-accepted 62-mile Karman Line – is widely debated and often arbitrary.
But when we say that the international community “recognizes” or “accepts” the 62-mile Karman Line as the edge of space, we are mostly talking about one organization: international aviation association, which tracks world records in spaceflight such as counting the number of people who have become astronauts.
But even the FAI said it was considering changing its definition to the 50-mile mark recognized in the United States in response to research from Jonathan McDowell With the Harvard-Smithsonian Center for Astrophysics.
What you should know: It’s not a huge deal. People traveling on Virgin Galactic and Blue Origin planes – both US-based – will remain in the US’s recognized version of outer space. (Although it should be noted, neither company is sending passengers into orbit.)
However, Blue Origin seized the opportunity on Friday to make a disaster defining outer space in a Twitter argument.