MAN: 10, 9, 8, 7...
Auto sequence start.
CC-212 ready to roll.
Um, can I just ask a quick question?
Where is space from here, exactly?
Anyone?
It might sound like a silly question, but it's good to know
if you're trying to get, well, up there,
something these two billionaires were also doing recently -
Virgin Galactic founder, Richard Branson
and Blue Origin founder, Jeff Bezos.
First, Branson and five friends went up
for a few low-gravity minutes.
RICHARD BRANSON: To the next generation of dreamers,
if we can do this,
just imagine what you can do.
Followed soon after by Bezos and his mates,
including the oldest and youngest people ever to go to space.
JEFF BEZOS: Blue Control, Bezos, best day ever!
Both companies are hoping these are the first
of many tourist trips to space.
Except there's one big thing these two disagree on -
where space actually is.
And they're not the only ones.
There's always been an argument about where does the atmosphere stop
and where does space begin?
Because there is no neat line,
there is no barrier that you break through.
Scientists divide our atmosphere into different layers,
starting with the troposphere,
where the air's nice and thick and easy to fly through.
After that is the stratosphere
and then the mesosphere.
For decades, NASA, the US Air Force and some astrophysicists
have considered that the start of space - 80 kays up.
In fact, that's when US astronauts get their wings -
a badge awarded on their very first successful space flight.
And Branson's Virgin Galactic flight went just over that - to 86 kays.
But Blue Origin claims,
by international standards, that wasn't quite space.
It reckons you have to go 100 kays up, not 80,
to the start of the thermosphere and something called the Karman Line.
It's named after this guy, an engineer and physicist
who in 1957 became the first person to try to define the edge of space.
Now the Karman Line is recognised by lots of scientists
and international organisations.
And it's what Bezos' Blue Origin was going by
when it sent him 106 kays up.
On how it felt - oh, my God.
(LAUGHTER)
Now, you might be thinking,
why does it even matter where space starts?
Does it matter really only to these companies
who are trying now to sell suborbital space tourism?
You know, and to title their passengers astronauts?
WOMAN: Copy, Astronaut Bezos.
(WHOOPING OVER RADIO)
RICHARD BRANSON: This remarkable crew
of mission specialists and now astronauts!
(CHEERING)
While those guys technically are astronauts,
some have pointed out that there's a big difference
between a 15-minute joyride and, you know,
what astronauts like me are doing.
What does that do?
Like travelling to the ISS, 400 kays away,
or going on a mission to the moon,
which is about 1,000 times further.
And of course, the further from Earth you go,
the more difficult and more expensive your ride gets.
But I guess if you do find yourself
with a spare few hundred thousand dollars
to spend on space travel in the future,
just make sure you're happy with how far you're going.
Come in, mission control.
I think I'm in space now.
Hello?