# Fall 40 Kilometers to Earth in a POV Video from Felix Baumgartner’s Helmetcam

Last year, daredevil Felix Baumgartner, sponsored by Red Bull, took a balloon up to a height of 39 kilometers (24 miles) and jumped out. Protected by a pressure suit, he quickly reached a speed of over 1300 km/hr (840 miles/hr). He fell for nine minutes before reaching the ground.

Snippets of the video from his helmetcam had been released before, but now the entire jump from start to finish has been posted:

Pretty interesting, and rather heart-pounding (as witnessed by Baumgartner’s heart rate going to nearly three beats per second). I strongly urge you to make it high-def and full screen. It’s pretty nifty.

First, even at the time, I was a bit cynical about the jump. A lot of people thought he was jumping from space, but that’s not at all the case; he was pretty dang high up, but the definition of space starts at an altitude of 100 km. He wasn’t even half that high up, and he was not in orbit; while the jump was technically very challenging and we may learn some engineering insight from it, I strongly doubt it’ll help NASA or private ventures learn much about escaping from a rocket on its way to (or already in) orbit. I explain at the link above, and my friend and space historian Amy Shira Teitel has details too.

I’ll note that Red Bull is careful to call this a jump from the stratosphere, which is correct. And don’t get me wrong: It was very cool, but overhyped in many circles. It should be taken for what it is.

Second, though, there is some fun stuff going on in the video. Baumgartner accelerates to a velocity of 700 km/hr in a mere 20 seconds. That means he was accelerating at an average of about 9.7 meters per second per second — just about what you’d expect for an object falling to Earth in a vacuum, where the only force is that of gravity. Pretty neat.

Another thing I found interesting was that as he fell the air became thicker, and he quickly reaches constant velocity. When you move around on Earth, you have to push air out of your way, and it pushes back. That’s a force acting on you, and the amount of that force depends on how quickly you move through the air, how much air you push aside (related to your surface area and shape; a cone moving tip-first has less air resistance than a cube, or a parabola facing into the wind, which is why parachutes slow you so much), and how thick the air is.