8 ms·
Supersonic free fall from 120,000 feet live at 8:30AM EST
- dutchbrit 14y agoCan someone explain the physics behind this?
- damian2000 14y agoThere's a bit of detail here from his jump in July at 90,000 ft ... http://www.dailymail.co.uk/sciencetech/article-2178943/Felix-Baumgartner-Skydiver-Fearless-Felix-leaps-18-MILES-Earth.html http://www.dailymail.co.uk/sciencetech/article-2178943/Felix...
- nicholassmith 14y agoLots of the science was broken down over at Wired: http://www.wired.com/wiredscience/2012/02/stratos-space-jump-can-you-fall-faster-than-the-speed-of-sound/ http://www.wired.com/wiredscience/2012/02/stratos-space-jump...
- davidw 14y agoAnother silly question might be: won't he "burn up on reentry"? Clearly, he's falling from a different altitude than a rocket, and starting from 0, but what are the actual numbers like?
- flipstewart 14y agohttp://www.redbullstratos.com/science/speed-of-sound/ http://www.redbullstratos.com/science/speed-of-sound/ Does that help or are you looking for something more specific or unmentioned?
- davidw 14y agoThat does not mention my question at all - or at least I don't see it.
- jlgreco 14y agoA great deal of the energy that needs to be bleed off during re-entry of a formerly orbiting spacecraft is the kinetic energy it had from basically moving sideways at an incredible speed.
- lutusp 14y ago> Clearly, he's falling from a different altitude than a rocket, and starting from 0, but what are the actual numbers like? Without an atmosphere, the result would be deterministic and trivial to compute: acceleration = f(t) = g velocity = ∫ f(t) dt = g * t position = ∫∫ f(t) dt = 1/2 g t^2 (The value of g changes slightly for this problem, in this altitude domain.) But because of the atmosphere, the calculation of velocity as a function of altitude is much more difficult. And it turns out that the atmospheric pressure as a function of altitude is not trivially characterized. And at high altitudes, it's not even constant -- it depends on temperature, the position of the sun in the sky, even the time in the 11-year sunspot cycle. The air resistance of a falling object is some constant k (based on the object's size and surface roughness) times the square of the velocity times the air pressure. But the air pressure is changing as the descent unfolds, so such a computation ultimately relies on a numerical solution to a differential equation. This is why one doesn't see a trivial equation describing descent velocity for a skydiver. I have worked out skydiver velocity profiles for constant air pressure nearer the surface: http://arachnoid.com/sage/terminal_velocity.html http://arachnoid.com/sage/terminal_velocity.html But this equation, only an approximation at lower altitudes, is of no use at all for a problem like the Baumgartner jump.
- bbrizzi 14y agoThe air pressure is proportional to either v or v² depending on the speed and atmosphere. For a friction force Fr, the terminal velocity is reached when the acceleration becomes null: mg + Fr = 0 mg - k* Vterm² = 0 k, the friction coefficient depends on different parameters: http://en.wikipedia.org/wiki/Drag_equation http://en.wikipedia.org/wiki/Drag_equation So in the end, the terminal velocity will depend on: - The guy's weight (contrary to a free-fall's acceleration which is independent of mass) - The "contact surface" between the body and the atmosphere. - The atmosphere's density (which is lower than on Earth's surface). The guy aims at reaching Mach 1. Note that due to the lower atmospheric pressure at this altitude, Mach 1 is a bit smaller than it is on the Earth's surface ( 301 m/s at 29 000 meters and -48 degrees C compared to 340 m/s at sea level ). Finally, the term "free fall" is not appropriate as the definition of a free fall is "any motion of a body where its weight is the only force acting upon it."( http://en.wikipedia.org/wiki/Free_fall http://en.wikipedia.org/wiki/Free_fall ) This does not take into account the drag which is not negligible here.
- blaze33 14y agoA typical low earth orbit re-entry speed is mach 25. Here with a max speed just above mach 1, there's 25²=625 times less energy to dissipate.
- delinka 14y agoIn addition to jlgreco's mention of 'sideways' momentum (like a shuttle re-entry) which this skydiver won't have, keep in mind he's falling from within the atmosphere so he's got resistance immediately and no chance to speed up to velocities that cause enough friction to burn up meteors. A meteor gets caught by Earth's gravity long before it touches Earth's atmosphere and has plenty of time to accelerate to fabulous speeds; when it hits the atmosphere, the speed makes for enough friction to burn/melt/destroy the thing.
- retube 14y agowell he's not going to achieve a speed greater than 700mph, somewhat less than an object entering the earth's atmosphere at 17,500mph
- yardie 14y agoNo. Rockets are descending from orbital velocity (30,000mph) to terminal velocity (700mph). They have a tremendous amount of energy they have to get rid of as they come down which they do as heat. Baumgartner is taking a balloon up and then freefalling down. He's no where near orbital velocity so his energy expenditure will just be some air friction. He might get a teensy bit warm on the way down.
- dantiberian 14y agoThis year has been really great for awesome space events. Mars, 2 SpaceX missions, now this. I hope this is just a taste of things to come.
- flipstewart 14y agoWe went to the moon, what, 40 years ago? It's about time we started living in the space age.
- draven 14y agoThere are precedents, see https://en.wikipedia.org/wiki/Joseph_Kittinger https://en.wikipedia.org/wiki/Joseph_Kittinger for other crazy skydives
- atlbeer 14y agoHe's working on the project as a consultant "The record is currently held by Col. Joe Kittinger, who in 1960 jumped from 102,800 feet as part of a U.S. Air Force mission. On this attempt, 52 years later, Kittinger is a consultant and mentor. He has also been giving Baumgartner advice on what to expect. For example, he described what it feels like to fall through space when there is so little air: "There's no way you can tell how fast you're going, because there's no visual cues." But Kittinger rejects any suggestion that he is jealous that Baumgartner is poised to beat his record. "Oh no. I'm delighted," he told CNN recently. "He's advancing science, and he'll do a great job." http://www.cnn.com/2012/10/09/us/skydiver-record-attempt/index.html?hpt=hp_t1 http://www.cnn.com/2012/10/09/us/skydiver-record-attempt/ind...
- yotsechan 14y agoHe also did an IAmA in support of the project a few weeks ago: http://www.reddit.com/r/IAmA/comments/yc1ke/i_am_joe_kittinger_record_holder_for_the_highest/ http://www.reddit.com/r/IAmA/comments/yc1ke/i_am_joe_kitting...
- mseebach2 14y agoYou have to be cut from a particular bitter length of cloth to be jealous over only keeping your world record for 52 years.
- jksmith 14y agoNo kidding. Breaking Kittinger's record is a tribute to Kittinger.
- aidos 14y agoHave a read of his Excelsior I jump [0], the near fatal 60,000 foot jump that was the precursor to the 102,000 foot one. Incredible. [0] http://stratocat.com.ar/artics/excelsior-e.htm http://stratocat.com.ar/artics/excelsior-e.htm
- chrisboesing 14y agoMaybe a little off topic: Red Bull's marketing is impeccable. They started out with all the actionsport athletes and moved upstream to more mainstream, and I guess, more expensive sports (two Formula 1 teams, more soccer teams than I can count), while still doing these crazy things. From Parcours in Santorini, to Air Races all over the world. Seems like every crazy sporting event is sponsored by Red Bull. I think these have allowed them to be still seen as "hip" and not just selling sugar water like Coca Cola.
- arethuza 14y agoThere are cases where smaller companies with good marketing can out sell Coca Cola in local markets - a good example being Irn Bru: http://en.wikipedia.org/wiki/Irn-Bru http://en.wikipedia.org/wiki/Irn-Bru
- Trezoid 14y agoRedbull: Sponsoring everything cool. It is, absolutely, a genius marketing strategy. Their primary demographic just happens to be the kinds of people who watch insane sports. Brand recognition from those events is huge, and then people just happen to drop their brand-name when talking about the events to other people. Probably cheaper in the long-run than trying to compete with someone like Coca Cola in more traditional campaigns, and way more effective.
- lloyddobbler 14y agoAgreed. And like Coke and Kleenex, through sheer brand awareness, they've achieved that rare feat in which a company's brand becomes synonymous with an object. In conversation throughout the world, Soft Drink = "Coke" Tissue = "Kleenex" Energy Drink = "Red Bull"
- franze 14y agoand like all good things, it started by accident. (i got this story from one of their marketing managers) once upon a time someone at the formula 1 won a race. and the masterchief (or however the bosses of the racing teams are called) drank a red bull instead of champagne during the victory interview. next day red bull was sold out in austria (which was their main market at that time) they just took it from there.
- andyv88 14y agoThe tech to shoot and transmit this whole event live is almost as incredible as the event itself http://www.redbullstratos.com/technology/cameras-communications/ http://www.redbullstratos.com/technology/cameras-communicati...
- mmaunder 14y agoNitpick re "edge of space": Low earth orbit starts at around 160 km and orbits decay rapidly below 200 km. This is 36 km altitude. But what I think most people miss is that to "be in space" the way most people think about space you'll need to enter orbit which means that once you get up to 160+ km altitude you need to go sideways at roughly 24 times the speed of sound - and then you're in orbit. Then when you're all done having your fun you need to take all that orbital energy and do something with it. The best idea so far is to use it to burn up a heat shield. This business of going vertical a little higher than jets and a lot lower than satellites is a little pretentious. But it's fun and it's Red Bull so who cares!!
- Retric 14y agoOnly a small fraction of orbital energy ends up burning the heat shield, most of it simply heats the air and creates a downdraft / wake.
- piaskal 14y agoWhile there isn't anything special marking the edge of space, the generally accepted definition is 100km https://en.wikipedia.org/wiki/Edge_of_space https://en.wikipedia.org/wiki/Edge_of_space
- coldarchon 14y agoThis means the Nazis with their V2 had been the first nation in space, which is why it's NOT generally accepted as we dont want this important part of our technologic development connected with them ..
- pbhjpbhj 14y agohttp://en.wikipedia.org/wiki/Air_sovereignty http://en.wikipedia.org/wiki/Air_sovereignty Makes me interested to see what the treaties say as I'd be surprised it no one thought to limit the control of countries to allow satellites to pass without permission or allow space vehicles in general. Though as you point out there is the Karman line convention.
- adastra 14y ago
- mschonfeld 14y agoActually, its at 9:30AM EST...
- deleted 14y ago[deleted]
- ColinWright 14y agoIs the web site overwhelmed? I'm getting "Loading Javascript" messages, but nothing is happening. We're just trying to load the data for you. If you don't have JavaScript enabled in your browser for this site, please switch it on and refresh the page in order to view the Live Jump experience. It would be nice to know if it's working for other people. Added in edit: OK - on weather hold - due off an hour from now.
- nicholassmith 14y agoThe YouTube live view seems like it's struggling to cope with the demand, keeps stalling or failing to load for me.
- keltex 14y agohttp://youtube.com/embed/vkJ5ItzE http://youtube.com/embed/vkJ5ItzE
- fredoliveira 14y agoI believe you're missing a few chars in the hash. Should be http://youtube.com/embed/vkJ5ItzEq3M http://youtube.com/embed/vkJ5ItzEq3M, or for the full youtube page: http://youtube.com/watch?v=vkJ5ItzEq3M http://youtube.com/watch?v=vkJ5ItzEq3M
- anu_gupta 14y agoDirect link to the live YouTube stream http://www.youtube.com/watch?&v=vkJ5ItzEq3M# http://www.youtube.com/watch?&v=vkJ5ItzEq3M#!
- rjsamson 14y agoLooks like they've got a weather hold until 8am Mountain Time (10am Eastern)
- NelsonMinar 14y agoWhile we're waiting for the weather to clear, you can watch nicely edited footage of Kittinger's 1960 record of 100,000 feet; it's at the start of the Boards of Canada video for Dayvan Cowboy: http://www.youtube.com/watch?v=A2zKARkpDW4 http://www.youtube.com/watch?v=A2zKARkpDW4
- deleted 14y ago[deleted]
- molmalo 14y agoAborted for today, due to too much wind.
- jchung 14y agoAborted.
- toufka 14y agoAnd it's aborted; 'Gusty winds'.
- nodesocket 14y agoJust aborted due to high winds. They are going to retry tomorrow.
- jayp08 14y agotomorrow also looks unlikely...no confirmation yet about tomorrow's jump as of now.
- keeptrying 14y agoSpeechless ...