Scientifically useful measurements from low-budget high-altitude balloon flights

Let's say, hypothetically, that I'm thinking about launching a high altitude balloon.

I want to contribute to the bank of mankinds' knowledge, not just take pretty pictures. My (notional) budget is around £300 ($450) for instrument payload, and my maximum payload weight is 2kg. I'm aiming for an altitude of at least 30km, and launching from the south of the UK. What measuments can I perform that would be genuinely useful to the scientific community? • Oww this is a bit broad. You could measure air pressure, temperature, wind speed, insolation, other radiation levels, lightnings, aurorae, count interaction of antimatter with high altitude atmosphere, air/road/maritime traffic, avian/bovine life, soil erosion, detect landslide/avalanche/earthquake/tsunami damage, air/water/light pollution, weather, you name it. Your budget would buy you a cam in protective enclosure, or a high quality microphone, an Arduino/Raspberry Pi, a couple of accelerometers, other sensors/receivers, and a data package with your fav mobile provider to access those live. Oct 3, 2015 at 16:38 • Yeah, tricky. Especially since you might want to simply add a couple more data points to an already ongoing project. How do you then measure your input, even if the whole project is an indisputable success? Most of measurable value of your project will be in man-hours you're willing to put into it. Oct 3, 2015 at 16:43 • OP "..aiming for an altitude of at least 30km.." @TildalWave "..a data package with your favorite mobile provider to access those live." Does that mean a device connecting to mobile phone towers on the ground? At 30Km distance? I'd have thought the same problem would crop up as causes problems for (mobile phones in) domestic jet aircraft, the phone screaming ever louder to get the 'ping' back from the tower on the ground. Am I understanding your suggestion correctly? Oct 3, 2015 at 16:56 • @AndrewThompson You might need a range extender, but they're not really rocket science (pardon the pun) so you might build one yourself if that's not within your budget. Tho I can find some high gain cell range extender antennae for about \$35 (cheaper if you buy used). Then launch into favorable conditions. You should be fine (depends on cell tower coverage, you might not be so fine over the North sea, over the Island or continental Europe - no problem, cell towers everywhere, sometimes even disguised as trees LOL). Oct 3, 2015 at 17:00
• @TildalWave Oh cool.. I learnt something new. Thanks. :) Oct 3, 2015 at 17:01

• repeated (and repeatable) observations that are
• systematically processed,
• hypotheses that get tested on experimental data,
• and conclusions that get peer review.

One high-altitude balloon with low-cost off-the-shelf sensor payload will add nothing to existing space/earth sciences if you do not do the following:

• read scientific journals / arXiv papers going back at least 10 years;
• formulate a list of unsolved problems in space/earth sciences;
• choose a few of the problems that can be re-worded into testable hypotheses that need some vertical profile data/high atmospheric measurements;
• verify that your budget allows you to design a data collection campaign with instrument accuracy and number of samples necessary to test the hypotheses;
• document all the decisions you make;
• do Monte Carlo hypothesis testing on mock data;
• calibrate your instrument package against standard sources/instruments (e.g. radiation sources if you are launching a Geiger counter) at the full range of environmental conditions that your balloon will encounter;
• publish the results (arXiv is the best bet here, you'd be well advised to team up with one or two subject matter experts - you can get more info by asking at Academia SE).

As a necessary reminder, you HAVE TO COORDINATE LAUNCH WITH LOCAL AIR CONTROL AUTHORITY.

If you can make the balloon reusable (that is, you can afford going to another country to pick it up or offer an award to any who find it), you stand a much higher chance of getting some stuff done. One vertical profile is unlikely to be useful, though.

After the first couple of papers you can apply for a grant to do more and better stuff without ruining your credit history (unless you are Alfred Lee Loomis or Howard Hughes-rich). No guarantees, but science enjoys economies of scale nowadays.

EDIT: for an insight into cutting-edge real-life high-altitude experiment design, please have a look at this answer at Aviation SE, describing astronomical observations from a Concorde.