The sensor head for the CHAOS-Junior weatherballon mission was put in the styrofoam box. The area was made light tight with black ducttape. The CPU of the Raspberry Pi Zero and the FPGA of the RPiRENA DAQ board were glued to copper bands that extend through the styrofoam, where another copper foil was placed outside. The copper bands were fixed with copper tape and covered with a second surface mirror foil used for space missions. That foil emits heat radiation but reflects sunlight. Two GPS trackers and a battery box were placed in the box. One of the GPS trackers sends the NMEA messages to the serial port of the Raspberry Pi (via the FPGA), to be recorded in the data file. A STRATO3 datalogger will be added. Maybe we will find a camera to add as well. The Raspberry Pi is online.