Yes, you probably won’t make it cross-country in 48 hours unless you catch the jetstream. However, if the balloon does catch the jet, chase team isn’t going to be making much, if any headway on gaining on them; been there/done that. Of course, in general, the longer it’s up, the farther it goes, the harder it is to chase. You need fuel, food, & bio breaks while the balloon keeps going. You need to follow roads while the balloon keeps going where the wind takes it. You’re not going to get any cell coverage up that high so don’t think it’s going to ping you with location updates from a phone. How are you going to keep things charged for a long duration? It’s not like a manned balloon flight where the pilot can swap out batteries as they die.
Instead of trying to build a balloon, why not get a weather balloon, a parachute for descent after it ‘reaches maximum altitude’. There are a number of videos on YouTube of others who have done this. However, instead of a GoPro, I suggest getting a Garmin Virb (get the original Virb, not the Virb XE as the original one has a longer battery life). The advantage of the Virb over a GoPro is that it had GPS & can show you it’s track, including altitude, direction, & speed natively.
I’ve been involved with gas ballooning I do aerial footage with GoPros & Virbs (though not at that altitude) & unstable platforms. Feel free to PM me with any questions if I don’t pop back in here soon enough.
It has better lift than helium, though only marginally (around 8%, IIRC). The main reason is that it’s cheaper, and the flammability is irrelevant for an unmanned, disposable balloon.
It’s also not depleting a finite resource… we can make infinite amounts of hydrogen, whereas when the helium is gone, that’s it forever. Better to use it for stuff that needs it.
Because it’s been done so much already it diminishes the ‘interesting’ requirement, and eliminates the ‘crazy’.
However, this sounds like a reasonable approach for testing cell phone transmission capability at altitude. The range for cell phone connections should be quite long but apparently it doesn’t work out well when that distance is in the up direction. I have to get more info about that, and see if any of my old HAM friends are still into this stuff for advice and alternatives. But I can send up test balloons that release the payload to test this kind of stuff, at least if I move inland before I send them up.
I certainly am interested in the GoPro device with GPS you mention, especially if it can be modified to operate at high altitude per Dr. Strangelove’s post.
As the probability of success for this project diminishes there’s a back burner alternative of a solar hot air blimp. It would be solar heated and use lightweight solar cells to power an electric motor. It’s not my first choice because the time and space needed for the build seemed impractical at first. As the high altitude balloon gets more complicated it may be the better choice in the end.
Light weight cells are what I was thinking of, but if it’s true that they could only add a few minutes over 2 days than it’s hardly worth the effort. I don’t know enough to do the calculations.
I haven’t done the calculations for a cell phone, but I was exaggerating. They are light weight, light enough they could be placed on the top of the balloon, and a lot of them will produce some decent amount of current. But they add weight which then requires a larger balloon which eventually could run into the weight limits to make this permissible, but I have to find out what that number is.
I’m not sure how much weight it could carry. I suppose it would depend on the size of the blimp, which of course is limited by law.
Obviously the thing would only float during the day, also I’m not sure how much height you could get. Would there be some height at which it would be so cold that heat would leave the blimp faster than the sun heats it?
Plenty of solar balloons have been made, I’d look for a powered blimp and try to set a distance record. A guy in Australia has made solar balloons that achieved great heights. I’ll post the link if I can find it. As altitude increases the air outside the balloon gets colder but the air inside only needs to be sufficiently warmer than outside to maintain lift.
At some point, the air outside would be less dense than the air in the balloon regardless of temperature, unless the balloon can expand enough without breaking or leaking.
In a hot-air balloon that’s about 100°F differential. Obviously could be smaller balloon/less differential if you’re only carrying a camera & communication device & not people.
But can you get sheets that are thin enough for your purpose? NASA high-altitude balloons use 20-micron thickness, which is barely thicker than saran wrap. JAXA/ISAS uses 3.4-micron thickness for their highest altitude balloons (they hold a world record of 50.7 km = 166,000 ft).
Pretty much necessity for solar balloons to be vented to keep them lightweight without bursting.
I can’t find the link to the Australian guy, but I’m sure he was well over 50,000 feet. Plain black PE is not the most efficient design, I’ve got some ideas on this to improve solar heat collection, but these things get big fast and the build time is just impractical right now.
Solar balloons can do some cool stuff. One proposal is to generate electricity with balloons on a tether. As the balloon rises the tether turns a generator. If you tether two balloons together through a pulley on the ground one can always be rising while the other falls after air is released when it hits maximum altitude. Very large balloons are more efficient weighing less relative to lift. I forget the calculations but balloons the size of football stadiums could produce some decent amount of power, but probably not for any practical purpose.
And if anyone has time and a large flat surface for building I’ll fund solar balloon projects, so long as they meet the requirements of fun, interesting, and crazy. (large values of crazy not required).
Lots of cool stuff like that. The helium will get outrageously expensive soon for such things but hydrogen could be used instead for unmanned craft. In this area I’d like to stick to solar balloons, much more challenging than lighter than air gases, but not practical for anything that has to stay up overnight.