If they put a pressure release valve on it (one designed to work by relative pressure differences, not absolute, and I think most are anyway), how high could you get?
I'm guessing to the point where the difference in mass between the helium inside the balloon and the air outside is not enough to loft the camera. But with a light camera that has to be just about outer space, no?
Edit: And despite the risk, I think they should use hydrogen. If I'm not mistaken, it's 1/4th the mass of helium. I don't know how much higher that will take them though, but it has to make some difference.
For balloon buoyancy it's not the atomic mass which matters, but rather the gas density. Hydrogen is about 50% less dense than helium. Obviously there are some safety issues, mostly with handling a pressurized storage tank on the ground.
That gets you hydrogen at ambient pressure. To get the hydrogen into the balloon you have to compress it at least a little bit. Running hydrogen through a compressor can be extremely dangerous if you don't have the proper equipment.
That is true, but it still doesn't demerit what they did. I find this to be pretty amazing, especially since done by students just a year or two younger than me.
"At over 100,000ft the balloon lost its inflation and the equipment was returned to the earth.
"We travelled 10km to find the sensors and photographic card, which was still emitting its signal, even though it had been exposed to the most extreme conditions."
Seriously. I ran a little experiment back one high school summer when I had a helium tank laying around and was bored/curious to know how far your typical lost-to-the-sky "Walmart" helium balloon would travel.
I launched about 50 balloons of varying inflation levels and groups (i.e. 1,2, and 3 balloons) and attached ribbons to them and tied laminated index cards with a numeric-ID and my email address.
I ended up getting a few responses and I believe one of the single balloons traveled over 76 miles before setting down in someone's backyard. The average was something like 50 miles, and that was on a warm night with <5mph wind.
Avoid the jet stream and trade winds. Specifically launch in the "Horse latitudes", and wait for a calm day. The very southern tip of spain is located in the horse latitudes.
The helium balloons probably didn't fall back down to earth as soon as the balloon in the story. But I still think that only 10 km seems pretty remarkable.
Good point, the rate of descent might have made a difference. This sounds like a good experiment. Let's release 10 heavy balloons (just like the ones they used) in pairs of 2 at 5 different locations around the world and track where each of them land. I'm not sure what scientific purpose this would serve but it would at least satisfy my curiosity.
Part 101 of the FAA Regulations covers balloons, kites and rockets. The
first section of Part 101 spells out exactly which kinds of devices the rest
of Part 101 applies to. Regarding "unmanned free balloons," Part 101 applies
if the balloon:
(i) Carries a payload package that weighs more than four pounds and has
a weight/size ratio of more than three ounces per square inch on any
surface of the package, determined by dividing the total weight in ounces
of the payload package by the area in square inches of its smallest surface;
(ii) Carries a payload package that weighs more than six pounds;
(iii) Carries a payload, of two or more packages, that weighs more than
12 pounds; or
(iv) Uses a rope or other device for suspension of the payload that
requires an impact force of more than 50 pounds to separate the
suspended payload from the balloon.
There is no limit to the karma you should receive for introducing me to my new hero, Lawn Chair Larry.
'He was immediately arrested by waiting members of the Long Beach Police Department; when asked by a reporter why he had done it, Walters replied, "A man can't just sit around."'
Lawn Chair Larry is the man. What a brilliant yet completely insane idea!
I especially like the part (not sure if it was mentioned in the Wiki article) where commercial airliners were reporting a man in a lawn chair at 15,000 feet. I would have loved to be eavesdropping on some of those cockpit discussions. Hey Bob! Say! Is that a man in a lawn chair over there next to that cloud? Whah?
If I'm not mistaken, they've started an annual race or something in his name.
Vietnam Vet, quit his job as a truck driver to be a motivational speaker which didn't work out, girlfriend of 15 years left him, only part-time employed as a security guard.
Illegal in Russia. We can't even buy aerial photography services - no online map of Russia has them. It's sad when your government denies you access to the skies.
Repeating for the third time: No online map has aerial imagery of Russia.
Note I said online map, not Google Earth which is a desktop application. (Although it's still true for Google Earth.) Also note I said aerial rather than satellite, and Russia rather than e.g. San Francisco. It amazes me that such a simple sentence has been misunderstood on all three points. A sign of the changing times?
"At over 100,000ft the balloon lost its inflation" wonderful euphemism.
Oblig. Hack:
Quite often I want to refer back to a particular phrase or word in a book, and I have a devil of a time finding it. At times I've methodically re-read 10 or 20 pages in failing to find it. I've wished I could just google the damn book.
I can. By using Google Books or Amazon's search facility. I mention this here, because I wanted to use an expression of Gladwell's in Outliers, about someone "customizing their environment", and then saying " "customize" -- using Lareau's wonderful term" on page 105. I'd misremembered it as "lovely euphemism".
And the blog in Catalan (see photos) http://teslabs.com/meteotek08/