This is a project where I participated a long time ago, its result was the report document.
This is not an ongoing project, rather just an entry of what happened back then.
The circuit that was used for the experiment was enclosed in the form of a probe and was launched with a meteorological balloon that climbed up to 30km, where the air temperature and pressure is similar to those found in space. The circuit was composed of a set of inexpensive electronic sensors and a data logger. The plan was to set up the data logger for recording, and upon recovery analyze the data, and compare to expected values and datasheet specifications, and see what kind of effects occurred on the various electronic components.
The full report can be downloaded on the link below.
The sketch has been uploaded, along with the first version of the main circuit schematic. The final version is missing the RTC chip. The schematic was designed using KiCad.