Trial and error

A project log for Low altitude flying electronics

Sending electronic devices in the air for cheap.

miawtthiasmiawtthias 06/01/2015 at 17:450 Comments

I couldn't resist until Tuesday. Due to the lack of wind I only was able to fly up to 5 m without any load.

Hydrogen balloons have the advantage of not needing any wind so I made a few calculations. Since I want to make the project as cheap as possible I'm going to focus on party balloons. I measured the pressure inside an inflated balloon to see if there was any significant overpressure that I would need to take into consideration. The overpressure is very small (about 30 hPa) so I'm going to neglect it.

Using Archimedes' principle I can get a rough idea of the maximal mass that a spherical balloon can lift up :

\color{White} \large m_{max}=\frac{4}{3}\pi r^{3}\left(\rho_{air}-\rho_{H_{2}}\right)

with a radius of 15 cm that makes a mass of about 15 g. Not that much so I'll have to use multiple balloons or find a cheap alternative for a bigger balloon.

Hopefully there will be more wind tomorrow.