Felix Baumgartner

**NordieBoy** · 15th October 2012, 08:39

He fcukin did it!

39,045m Altitude
36,500m freefall
1342.8 km/h
Mach 1.24

Chuck Yeager did Mach 1.06 on the 14th October 1947.

Andy Green did Mach 1.02 on the 15th October 1997.

**Bass** · 15th October 2012, 09:26

Quite an achievement I agree, but as usual the media doesn't tell the whole story.
The speed of sound is the average speed of the component molecules and so in a gas it depends on temperature and only on temperature. At a height of somewhere around 30,000 meters, the air temperature would be what? Well in a 747 at about 13,000 meters it's around -50 celcius and so at 30,000, I'm guessing it's well below -100 celcius.
The point is that sonic velocity is much lower way up there so you can't compare it to Chuck Yeager, Andy Green etc etc.

Further, for him to be able to go fast enough to break through his own shock wave with only his own weight as the driving force, the air density would have to be WAY down. So again, the comparason with Yeager et al is not valid unless you tell the whole story.

On the other hand, the mach number you quote, looks to me like it uses mach 1 at sea level as the denominator. So in reality, his mach number may have been much higher.

**steve_t** · 15th October 2012, 09:29

Badass! I wanna see the GoPro footage!

**skippa1** · 15th October 2012, 09:44

Originally Posted by Bass

Quite an achievement I agree, but as usual the media doesn't tell the whole story.
The speed of sound is the average speed of the component molecules and so in a gas it depends on temperature and only on temperature. At a height of somewhere around 30,000 meters, the air temperature would be what? Well in a 747 at about 13,000 meters it's around -50 celcius and so at 30,000, I'm guessing it's well below -100 celcius.
The point is that sonic velocity is much lower way up there so you can't compare it to Chuck Yeager, Andy Green etc etc.

Further, for him to be able to go fast enough to break through his own shock wave with only his own weight as the driving force, the air density would have to be WAY down. So again, the comparason with Yeager et al is not valid unless you tell the whole story.

On the other hand, the mach number you quote, looks to me like it uses mach 1 at sea level as the denominator. So in reality, his mach number may have been much higher.

you should really have forwarded your guesses to the organisers so that they could have factored them into any claims of success. Without the proper information they have really been making unjustified claims, it is clear now that your guesses are key to any accurate claim of success.

**sinfull** · 15th October 2012, 09:45

Originally Posted by Bass

Quite an achievement I agree, but as usual the media doesn't tell the whole story.
The speed of sound is the average speed of the component molecules and so in a gas it depends on temperature and only on temperature. At a height of somewhere around 30,000 meters, the air temperature would be what? Well in a 747 at about 13,000 meters it's around -50 celcius and so at 30,000, I'm guessing it's well below -100 celcius.
The point is that sonic velocity is much lower way up there so you can't compare it to Chuck Yeager, Andy Green etc etc.

Further, for him to be able to go fast enough to break through his own shock wave with only his own weight as the driving force, the air density would have to be WAY down. So again, the comparason with Yeager et al is not valid unless you tell the whole story.

On the other hand, the mach number you quote, looks to me like it uses mach 1 at sea level as the denominator. So in reality, his mach number may have been much higher.

Jesus wept !

**NordieBoy** · 15th October 2012, 12:14

The speed of sound at 38,000m at 45 deg north in July is 318m/s or 1,144kph.

**Bass** · 15th October 2012, 14:49

Originally Posted by NordieBoy

The speed of sound at 38,000m at 45 deg north in July is 318m/s or 1,144kph.

Not according to this

http://www-mdp.eng.cam.ac.uk/web/lib...mos/atmos.html

Using this data, mach1 at 30 km up calculates to a tad over 300 m/s which is exactly what your original figures calculate to and so I stand corrected.

My apologies.

I have always used a rule of thumb for mach 1 at sea level being around 1000 km/hr. However that's not correct and it's actually about 1225 km/hr

Never too old to learn it seems. Also, my air temperature guess was way out as evidenced by the graph in the reference linked. Doh!

The really stupid part is that I've seen that graph before. Double Doh!

**Rhys** · 15th October 2012, 14:58

**White trash** · 15th October 2012, 15:38

Originally Posted by Bass

Not according to this

http://www-mdp.eng.cam.ac.uk/web/lib...mos/atmos.html

Using this data, mach1 at 30 km up calculates to a tad over 300 m/s which is exactly what your original figures calculate to and so I stand corrected.

My apologies.

I have always used a rule of thumb for mach 1 at sea level being around 1000 km/hr. However that's not correct and it's actually about 1225 km/hr

Never too old to learn it seems. Also, my air temperature guess was way out as evidenced by the graph in the reference linked. Doh!

The really stupid part is that I've seen that graph before. Double Doh!

Someone admitting they were wrong on KB?! You're a witch, burn him!

**Waipukbiker** · 15th October 2012, 16:48

Just seems a bit odd because Im one of those strange buggers that used to jump out of perfectly sound aircraft and you could only reach a certain speed free falling, even diving to streamline yourself, Its called terminal velocity and its about 320 KPH.
Ok, he was up in thinner atmosphere so there was much less resistance so even if he did get to break the sound barrier a couple of other things crop up, in the early days , aircraft used to fly to bits with the buffeting near the sound barrier until they got the structural side of it sorted out. If he got to the speed of sound, what happens when he started getting into the heavier atmosphere at that speed,
Just whipped a portable heat shield out of his pocket?
Obviously he had that all sorted but still makes ya wonder how he did it.

**Night Falcon** · 15th October 2012, 17:10

my brain hurts reading this thread

that space suit looked cool though especially with the KTM Red Bull livery

**Bass** · 15th October 2012, 18:54

Originally Posted by Waipukbiker

If he got to the speed of sound, what happens when he started getting into the heavier atmosphere at that speed,
.

It's the transonic effects of this that have me really intrigued too.
He would have been at his terminal velocity (relative to altitude) all the way after about the first 60 seconds. He was wearing a pressure suit and so couldn't feel the airflow, so did he even notice the sharp rise and fall in drag as he transited mach 1?
How did he get out of the flat spin that threatened a forced abort? Was he still supersonic at the time?
All sorts of stuff like that - I'd love to know.
I must be a nerd.

**chasio** · 15th October 2012, 19:07

Originally Posted by Bass

It's the transonic effects of this that have me really intrigued too.
He would have been at his terminal velocity (relative to altitude) all the way after about the first 60 seconds. He was wearing a pressure suit and so couldn't feel the airflow, so did he even notice the sharp rise and fall in drag as he transited mach 1?
How did he get out of the flat spin that threatened a forced abort? Was he still supersonic at the time?
All sorts of stuff like that - I'd love to know.
I must be a nerd.

Me too.

Also I have looked carefully at the video and pictures and cannot see that the suit he used has space for testicles the size of watermelons. So how did they fit them in, huh? The testicle detail of it all is quite fascinating...

**jellywrestler** · 15th October 2012, 19:13

Originally Posted by Bass

Quite an achievement I agree, but as usual the media doesn't tell the whole story.
The speed of sound is the average speed of the component molecules and so in a gas it depends on temperature and only on temperature. At a height of somewhere around 30,000 meters, the air temperature would be what? Well in a 747 at about 13,000 meters it's around -50 celcius and so at 30,000, I'm guessing it's well below -100 celcius.
The point is that sonic velocity is much lower way up there so you can't compare it to Chuck Yeager, Andy Green etc etc.

Further, for him to be able to go fast enough to break through his own shock wave with only his own weight as the driving force, the air density would have to be WAY down. So again, the comparason with Yeager et al is not valid unless you tell the whole story.

On the other hand, the mach number you quote, looks to me like it uses mach 1 at sea level as the denominator. So in reality, his mach number may have been much higher.

forget all that shit, he had four and a half minutes, enough time for one hell of a danger wank!

**NordieBoy** · 15th October 2012, 19:52

Originally Posted by Bass

Not according to this

http://www-mdp.eng.cam.ac.uk/web/lib...mos/atmos.html

Using this data, mach1 at 30 km up calculates to a tad over 300 m/s which is exactly what your original figures calculate to and so I stand corrected.

My apologies.

I have always used a rule of thumb for mach 1 at sea level being around 1000 km/hr. However that's not correct and it's actually about 1225 km/hr

Never too old to learn it seems. Also, my air temperature guess was way out as evidenced by the graph in the reference linked. Doh!

The really stupid part is that I've seen that graph before. Double Doh!

I used this one...
http://www.engineering.uiowa.edu/~cf...ables/7-2B.pdf