Red Bull Stratos LIVE

[bobswire]

If the weather holds approx 3 hrs from now a man will be gently lifted into space via a balloon until it reaches 120,000 feet at which time he'll jump out of the balloon to plummet back to earth reaching speed enough to break the sound barrier and hopes to survive the experience.

http://www.youtube.com/redbull

[Tony T]

Story on NYT: Daredevil Sets Sight on a 22-Mile Fall (http://www.nytimes.com/2012/10/09/science/fearless-felix-baumgartner-to-try-to-become-first-sky-diver-to-break-sound-barrier.html?hp)

http://graphics8.nytimes.com/images/2012/10/09/science/09jump1/09jump1-articleInline.jpg
Mr. Baumgartner prepared to jump
during the first manned test flight over
Roswell, N.M., on Monday.

[FlashUNC]

Anyone else a little apathetic about this?

He's not jumping from all that much higher than the record set in 1960.

http://en.wikipedia.org/wiki/Project_Excelsior

[sworcester]

Anyone else a little apathetic about this?

He's not jumping from all that much higher than the record set in 1960.

http://en.wikipedia.org/wiki/Project_Excelsior

Can you go much higher?

Still about 116157' higher than I want to jump from. But in space, no one can hear you cry "MOMMY!"

[echelon_john]

I don't like getting up on the roof, so I'm pretty impressed.

[Tony T]

Anyone else a little apathetic about this?

He's not jumping from all that much higher than the record set in 1960.


Others have tried and failed. (and one guy died when his suit depressurized).
To see the curvature of the earth when he jumps is amazing.

[crownjewelwl]

Anyone else a little apathetic about this?

He's not jumping from all that much higher than the record set in 1960.

http://en.wikipedia.org/wiki/Project_Excelsior

this dude didnt break the sound barrier

[bobswire]

Anyone else a little apathetic about this?

He's not jumping from all that much higher than the record set in 1960.

http://en.wikipedia.org/wiki/Project_Excelsior

Yeah and when was the last time someone set a foot down on the moon?

There is a reason those feats have not been tested since.

[wallymann]

read his book, it's a good one! kittinger was truly a trail blazing proto-astronaut.

Come Up and Get Me: An Autobiography of Colonel Joseph Kittinger (http://www.amazon.com/Come-Up-Get-Autobiography-Kittinger/dp/0826348033)

yeah, the physics dictate that baumgartner will not go supersonic -- that's just Red Bull fueled hype.

[Tony T]

yeah, the physics dictate that baumgartner will not go supersonic -- that's just Red Bull fueled hype.

What is the physical barrier preventing him breaking the sound barrier at that altitude?

[FlashUNC]

Yeah and when was the last time someone set a foot down on the moon?

There is a reason those feats have not been tested since.

The reason we haven't tested this since is that there's no reason to. Kittinger proved you can eject from a craft at that altitude and survive. There was a reason to do so. This just strikes me as a fancy stunt.

There's plenty of reasons to go back to the moon.

I'm also put off by all the "RED BULL EXTREME" nonsense.

[dnades]

Gravity. I cannot for the life of me remember the formula but I seem to remember a body falling toward earth will max out at a certain speed and then stay constant(in a vacuum anyway). He'd need some form of propulsion to break the sound barrier I think.

[MattTuck]

Gravity. I cannot for the life of me remember the formula but I seem to remember a body falling toward earth will max out at a certain speed and then stay constant(in a vacuum anyway). He'd need some form of propulsion to break the sound barrier I think.

Gravity has no speed limit, you'll be accelerated (on earth) at 9.8 meters / second squared.

You reach terminal velocity when the force from wind resistance equilabrates with the force from acceleration due to gravity.

I'm not sure of the density of the air where he is jumping from, but he may break the speed of sound at sea level, but if the air is thin, that may not be the speed of sound where he is.... make sense? If he were really interested in achieving maximum speed, maybe he'll jump out in a missile shaped tube?

[crownjewelwl]

Gravity has no speed limit, you'll be accelerated (on earth) at 9.8 meters / second squared.

You reach terminal velocity when the force from wind resistance equilabrates with the force from acceleration due to gravity.

I'm not sure of the density of the air where he is jumping from, but he may break the speed of sound at sea level, but if the air is thin, that may not be the speed of sound where he is.... make sense?

and there isn't enough resistance at his altitude to slow him down before going supersonic

[Mark McM]

Gravity. I cannot for the life of me remember the formula but I seem to remember a body falling toward earth will max out at a certain speed and then stay constant(in a vacuum anyway). He'd need some form of propulsion to break the sound barrier I think.

Nope. You're misrembering - terminal velocity is caused by atmospheric drag; without a drag force, one would continue accelerating indefinitely under gravity (well, at least until you hit the ground).

There's a very good reason he's starting the jump so high - the higher you go, the less dense the air. This is important because:

1) The less dense the air, the lower the aerodynamic drag, and therefore the higher the terminal velocity; and

2) The less dense the air, the lower the speed of sound.

So, there is some critical altitude as which terminal velocity is above the speed of sound. So, as long as you jump from high enough, you can break the sound barrier in free-fall.

[dnades]

there we go! I new I butchered that.

[Tony T]

Also, low temperature at higher altitude = lower speed of sound.

[MattTuck]

Also, back to the original topic of the thread... I don't understand how Red Bull sells enough cans of energy drink to finance these crazy things....

It is cool that they do, but how many cans of energy drink do you need to sell to get enough profit to pay for this? And how many will this stunt cause people to buy?

[wallymann]

What is the physical barrier preventing him breaking the sound barrier at that altitude?

accelleration due to gravity vs. air resistance

as kittenger showed...he'll go fast, but i dont think he'll break the sound barrier. again, just like kittinger.

starting from 0 velocity at 120Kft altitude, he'll be accelerated by gravity @ 9.8m/sec/sec (thats the accelleration due to gravity in a vacuum). my gut says he'll hit Vmax at something approaching 100Kft. at that altitude, the speed of sound is ~590mph or 300m/sec which would require ~30sec of unimpeded acceleration to achieve.

and double-checking my gut, 30sec accellerating at 9.8m/s/s covers about 4400meters which is roughly 15Kft descended.

it's not like he's at 17000mph orbital velocity, he's at a stand-still and accelerating due to free-fall from a balloon...and the balloon requires air for levitation. every foot he descends his air resistance is constantly increasing.

also he's not doing a true free-fall, he has a stabilizing chute to keep from spinning out of control so his drag is more than just himself, it includes a parachute.

i believe he'll never get to 1.0mach.

[azrider]

Also, back to the original topic of the thread... I don't understand how Red Bull sells enough cans of energy drink to finance these crazy things....

It is cool that they do, but how many cans of energy drink do you need to sell to get enough profit to pay for this? And how many will this stunt cause people to buy?

not sure how many cans they sold but they made two guys pretty rich....or is that filthy rich?

At the same time Mateschitz and Chaleo Yoovidhya founded Red Bull GmbH; each investing $500,000 of savings and taking a stake in the new company. Chaleo and Dietrich each held a 49% share of the new company. They gave the remaining 2% to Chaleo's son Chalerm, but it was agreed that Mateschitz would run the company.[11] The product was launched in 1987 in Austria, in a carbonated format.

In 1992 the product expanded to international markets: Hungary and Slovenia.[12] It entered the United States via California in 1997[12] and the Middle East in 2000.[13] In 2008, Forbes magazine listed both Chaleo and Mateschitz as the 260th richest people in the world with an estimated net worth of $5 billion.[

[binxnyrwarrsoul]

Aborted.

[crownjewelwl]

2) The less dense the air, the lower the speed of sound.



not to get too technical, but the speed of sound is lower at higher altitude because of lower temperature...the decreased density and decreased pressure cancel each other out

[Tony T]

http://upload.wikimedia.org/wikipedia/commons/thumb/9/9d/Comparison_US_standard_atmosphere_1962.svg/512px-Comparison_US_standard_atmosphere_1962.svg.png

Density and pressure decrease smoothly with altitude, but temperature (red) does not. The speed of sound (blue) depends only on the complicated temperature variation at altitude and can be calculated from it, since isolated density and pressure effects on sound speed cancel each other. Speed of sound increases with height in two regions of the stratosphere and thermosphere, due to heating effects in these regions.

[wallymann]

a couple big-questions for you:

- can a balloon that requires air for buoyancy lift a person and associated equipment up to this mythical altitude?
- how much does the drag of a person + a stabilizing drogue-chute affect this equation?


So, as long as you jump from high enough, you can break the sound barrier in free-fall.

[goonster]

I don't understand how Red Bull sells enough cans of energy drink to finance these crazy things....
Their operating expenses are very low. AFAIK, Red Bull does not directly own a single truck or bottling plant, nor do they directly employ anyone who makes or delivers the product. All manufacturing is contracted out.

I don't know exactly how many employees they have, but mostly what they do is figure out how to promote the brand. The cost of dropping Felix Baumgartner from his balloon, complex though it is, surely pales in comparison to the cash that goes into running two F1 teams.

[Mark McM]

a couple big-questions for you:

- can a balloon that requires air for buoyancy lift a person and associated equipment up to this mythical altitude?
- how much does the drag of a person + a stabilizing drogue-chute affect this equation?

- Baumgartner intends to jump at about 120,000 ft. and people have already gone higher than that in helium balloons.

- Obviously this depends on many variables, including the design and size of the pressure suit and drag chute. However, the previous speed record was set by Joe Kittinger at about 0.9 times the speed of sound. Kittinger's jump was over 50 years ago, from a lower height (102,000 feet), and he was just testing the ability to survive a jump from this altitude, and was not specifically going for a speed record.

While we can't say whether Baumgarner will be successful, I think it is within the realm of possibility that someone will be able to break the sound barrier in freefall.

[wallymann]

did some googling: the highest manned balloon flight was 113K feet in 1961...not long after kittinger's jump, so not alot of progress has been made on the manned front. keep in mind that the record setting balloon had a sealed and pressurized gondola, quite unlike kittinger's open gondola. i think baumgartner is doing the same, an open gondola.

unmanned balloons have gone up to 170K feet, but they have a much simpler lift/payload equation. heavy person, heavy pressure suit, heavy comms/elec equipment, heavy O2 canisters to sustain life during the ascent and free-fall (plus extra for riding back down on the balloon), and a big chunk of frozen CO2 for cooling (it's true).

given the weight penalty of manned flight, apparently the theoretical max altitude for a balloon in earth's atmosphere is something like 140K feet. given that not much progress has been made here, getting to that limit does not appear to be particularly easy.

it would be neat if someone dropped a really aerodynamic weighted sensor (or an iphone!) from the balloon and measured it's descent and max-speed.

- Baumgartner intends to jump at about 120,000 ft. and people have already gone higher than that in helium balloons.

- Obviously this depends on many variables, including the design and size of the pressure suit and drag chute. However, the previous speed record was set by Joe Kittinger at about 0.9 times the speed of sound. Kittinger's jump was over 50 years ago, from a lower height (102,000 feet), and he was just testing the ability to survive a jump from this altitude, and was not specifically going for a speed record.

While we can't say whether Baumgarner will be successful, I think it is within the realm of possibility that someone will be able to break the sound barrier in freefall.

[wildboar]

http://www.telegraph.co.uk/science/space/9595760/Skydiver-Felix-Baumgartner-attempts-to-break-sound-barrier-live.html
Latest

20.10 Well we're going to wrap this live blog up for today. Unfortunately we didn't get to see the death-defying leap, and we won't tomorrow either to give Felix and his crew a day off. He only has one more attempt apparently, as he has one back-up balloon. That will be Thursday at the earliest, although as mentioned before, the weather doesn't look great.



19.20 Is this the most expensive gust of wind ever? Nick Allen emails:

That was an expensive gust of wind. The giant balloon that would have lifted Fearless Felix to the stratosphere cost an estimated $250,000, and it cannot be re-used. Fortunately, he has a back-up balloon.

[MadRocketSci]

not to get too technical, but the speed of sound is lower at higher altitude because of lower temperature...the decreased density and decreased pressure cancel each other out

<nerd alert>
getting more technical the speed of sound is the change in pressure wrt the change in density at constant entropy (isentropic), dP/drho |s where d is the partial derivative. Using an ideal gas assumption, you get the temp dependent only equation speed of sound = sqrt(gamma(=1.4 for air)*R(287 in MKS units)*T(in Kelvin))
</nerd alert>

[Germany_chris]

<nerd alert>
getting more technical the speed of sound is the change in pressure wrt the change in density at constant entropy (isentropic), dP/drho |s where d is the partial derivative. Using an ideal gas assumption, you get the temp dependent only equation speed of sound = sqrt(gamma(=1.4 for air)*R(287 in MKS units)*T(in Kelvin))
</nerd alert>

There's a reason I dislike math..thanks for reminding me :p

[Louis]

Two things:

F = ma <===== Force due to gravity

F = rho x v^2 x Cd x A <====== Force due to drag

m = mass
a = acceleration due to gravity

rho = density of air
v = velocity
Cd = drag coefficient
A = area

[MadRocketSci]

There's a reason I dislike math..thanks for reminding me :p

i don't particularly enjoy math for its own sake, its just the language we have to use to talk to the universe :)

[MadRocketSci]

Two things:

F = ma <===== Force due to gravity

F = rho x v x Cd x A <====== Force due to drag

m = mass
a = acceleration due to gravity

rho = density of air
v = velocity
Cd = drag coefficient
A = area

slight edit, Force due to the drag is missing a v...ie,

rho x v x v x Cd x A

traditionally there is a 1/2 in there also, but i suppose that could be absorbed into the definition of Cd....(the 1/2 comes from 1/2*rho*v^2, which is called dynamic pressure, which is most famously used in the simplest form of Bernoulli's eqn, P + 1/2xrhoxv^2 = stagnation Pressure = constant)

ok i'm done being a geek for now....

[jmeloy]

took two tylenols after that exchange
:)

slight edit, Force due to the drag is missing a v...ie,

rho x v x v x Cd x A

traditionally there is a 1/2 in there also, but i suppose that could be absorbed into the definition of Cd....(the 1/2 comes from 1/2*rho*v^2, which is called dynamic pressure, which is most famously used in the simplest form of Bernoulli's eqn, P + 1/2xrhoxv^2 = stagnation Pressure = constant)

ok i'm done being a geek for now....

[Louis]

slight edit, Force due to the drag is missing a v...

You're right - it is v^2. I'll edit the post.

[echelon_john]

Let me know if I can get you guys a beer or anything. That's pretty much the extent of what this English major can contribute to this.

[MadRocketSci]

Let me know if I can get you guys a beer or anything. That's pretty much the extent of what this English major can contribute to this.

Hey, i'll take knowing what the symbolism behind the blue light across the harbor at the end of the Great Gatsby was all about...

[MadRocketSci]

You're right - it is v^2. I'll edit the post.

in case any math-phobes are curious why drag varies with the square of velocity, ie, why its much harder to ride at 25 than 20, its because with increasing v, 1) you are interacting/colliding with more gas molecules and 2) you are increasing the change in those gas molecules' momentum.

[Germany_chris]

This is why I was a Philosophy Major and now Business Major

[binxnyrwarrsoul]

This is why I was a Philosophy Major and now Business Major

And why I drive a truck for a living.

[Louis]

in case any math-phobes are curious why drag varies with the square of velocity, ie, why its much harder to ride at 25 than 20, its because with increasing v, 1) you are interacting/colliding with more gas molecules and 2) you are increasing the change in those gas molecules' momentum.

More for the math-phobes:

Furthermore, the v^2 term is one of the reasons (in terms of avg speed for the whole climb + descent) that you never get out of a hill as much as you put in. Going up gravity fights you, drag is very low because you're not going fast. Going down gravity helps you, but drag is much higher (because you are going faster) and non-linear, so you loose a lot more energy due to the aero drag. Bottom line: there is no conservation of energy. So unless you absolutely kill yourself (especially going up) a significant hill will always reduce your avg speed.

Caveat: I haven't worked out all the equations on this, so I'm not 100% sure, but I'm guessing that if aero drag were linear with speed you'd be a lot closer to having conservation of energy for the climb + descent, which would mean that the hill is less likely to reduce your average speed. There are tons of other variables but I think they are secondary.

[hairytorus]

Oh so epic.

[MattTuck]

This thing is on like donkey kong.

[Tony T]

Interesting to note that 65 years ago today Chuck Yeager broke the sound barrier.

[Bruce K]

That was pretty cool.

It's a shame he didn't get the freefall record along with the altitude and speed records but it's kind of neat that Kittenger keeps something for a while.

BK

[wallymann]

well done, felix!

Brian Utley of the FAI, the international federation that certifies aerospace records, told reporters at a news conference that according to a preliminary analysis, Mr. Baumgartner reached a maximum speed of 833.9 mph during his jump from more than 24 miles over the New Mexico desert. That is a speed of Mach 1.24.

http://www.nytimes.com/2012/10/15/us/felix-baumgartner-skydiving.html

[oldpotatoe]

Also, back to the original topic of the thread... I don't understand how Red Bull sells enough cans of energy drink to finance these crazy things....

It is cool that they do, but how many cans of energy drink do you need to sell to get enough profit to pay for this? And how many will this stunt cause people to buy?

Add air racing, F1, boat racing, drag racing, very deep pockets those gents from Thailand.

[gdw]

Interesting stunt but lets be real...any serious skydiver would have tried it if they had the sponsorship. Kittenger's record lasted so long because no one had the cash to try to break it.

[wallymann]

Interesting stunt but lets be real...any serious skydiver would have tried it if they had the sponsorship. Kittenger's record lasted so long because no one had the cash to try to break it.

gross oversimplification of the difficulty and why it's stood so long...it was also a VERY technically challenging jump. not only the jump itself, but getting to 130K feet w/o getting killed along the way. kittinger helped because he understood they were serious and competent, as well as well-funded.

[Seramount]

Interesting stunt but lets be real...any serious skydiver would have tried it if they had the sponsorship. Kittenger's record lasted so long because no one had the cash to try to break it.

I'm a professional cynic and I don't buy this petty assessment either...

cash was not the limiting factor here.

[alastair]

Interesting stunt but lets be real...any serious skydiver would have tried it if they had the sponsorship. Kittenger's record lasted so long because no one had the cash to try to break it.

As a former paratrooper with free fall training, I'd say your assessment isn't consistent with my training and experience.

[Louis]

I believe several people have been killed trying to break Kittinger's record. It's not a trivial task.

[MattTuck]

Watching him jump out and start tumbling at what i'd estimate was 2 revs per second, did not make it look so simple.

[Bruce K]

Plus he accelerated to 1.24 Mach !!!

He broke the freakin' Sound Barrier without an airplane!

Tumbling like that at speeds like that and then having the mental accuity, strength, and training to stabilize yourself....

Let's give the guy some serious credit here.

BK

[gdw]

"gross oversimplification of the difficulty and why it's stood so long...it was also a VERY technically challenging jump. not only the jump itself, but getting to 130K feet w/o getting killed along the way. kittinger helped because he understood they were serious and competent, as well as well-funded."


You proved my point. I respect Baumgarten but he never would have been able to make the jump without Redbull's money. The techicians, balloon, and equipment aren't available to the masses. As to the technical difficulty of the jump itself, lots of experienced jumpers have the guts and skill needed for the attempt.

"As a former paratrooper with free fall training, I'd say your assessment isn't consistent with my training and experience."

Really? What was your MOS and what units were you with?:banana:
Seriously, we share the same background and I continued to jump after the service. I've been exchanging emails with some friends, one with 6000 jumps, and all of them wouldn't turn down an opportunity to set a new record. Maybe we're jealous.... over 4 minutes of freefall....

[BumbleBeeDave]

. . . looks like a new Pinarello--a million freakin' logos!

BBD

[goonster]

Add air racing, F1, boat racing, drag racing, very deep pockets those gents from Thailand.
Ahem . . .

They may have ripped the product idea off from Thailand, and the other founding partner is Thai, but Red Bull are an Austrian company.

[jimcav]

on a jump like this when you tumble/spin. The news was saying he could have died... does the suit squeeze like a fighter pilot's in response to G-force of spinning to help keep blood going to the brain?
If he passed out, I assume his shoot would deploy on auto at some altitude, but I believe from a MFF death investigation I was on that those types of chutes hit the ground at 28 mph if simply running with the wind-- (ie no control/input from the oeprator)?
thanks
jim

[CaliFly]

on a jump like this when you tumble/spin. The news was saying he could have died... does the suit squeeze like a fighter pilot's in response to G-force of spinning to help keep blood going to the brain?
If he passed out, I assume his shoot would deploy on auto at some altitude, but I believe from a MFF death investigation I was on that those types of chutes hit the ground at 28 mph if simply running with the wind-- (ie no control/input from the oeprator)?
thanks
jim


My wife asked the same question when he started tumbling. Interested in the answer.

[gdw]

The big fear when Kittenger and the other test jumpers were establishing the records in the early sixties was the flat spin. Test dummies dropped from 100,000 ft had reached 200 revolutions per minute and scientists at that time felt that 140 revolutions per minute could be fatal. High speed tumbling or spinning can also prevent the main chute from properly deploying. The jumper could become entangled in the lines and chute or the chute could be so twisted that is can't open.

The Air Force developed a drag chute which stabilized the jumper as they fell to deal with the problem. Kittenger experienced a malfunction of his drag chute, it deployed too early, on his first balloon jump at 76,000ft and started to spin so rapidly that he passed out. Fortunately his reserve, which was set to open automatically at 10,000ft, worked and saved his life. Baumgartner must have used a similar system.

The speed at which a chute travels is dependent upon its design and the wind.

There's an old National Geographic article on Kittenger's jump which can be found on the net. It's worth reading. He's an amazing man.