In 2019, the team from Nordhausen University of Applied Sciences was selected among other European student teams to realize the BEXUS-ELFI (Extremely Low Frequency and IMU) experiment with support from the German Aerospace Center (DLR), the European Space Agency (ESA) and the Swedish National Space Agency (SNSA). The scientific goal was to measure extremely low-frequency magnetic fields, for example caused by the ailroad power supply, the energy supply or as Schumann frequency. In preparation for their airy experiment, the young scientists were able to familiarize themselves with the real thing during a training week in northern Sweden in February 2020. North of the Arctic Circle, where temperatures can drop to minus 28 degrees Celsius, the time had come for the balloon launch in September 2021.
To support ambitious scientists in their research, Coroflex is happy to assist with material and know-how. We have been cooperating with Nordhausen University of Applied Sciences since 2007 and have made an important contribution to the success of the BEXUS-ELFI experiment with robust silicone cables. Once again, this application proves how versatile Coroflex cables are. The stratospheric balloon that the students used for their measurement has a coil of copper wire below the gondola that acts as an antenna. It is mounted on a scissor arm that is still retracted at launch and unfolds downward after a few meters of altitude, causing the coil to lower. The gondola contains the measuring device developed in-house, from which Coroflex cables lead to the coil. A particular challenge: They have to be insensitive to the cold, after all, the temperature reaches regions as low as minus 61 degrees Celsius. Our silicone cables mastered all the requirements with bravura and scored points for their end-to-end flexibility.
The cables are exposed to special requirements: The cold is a major challenge, the cables must transmit reliably and must also not become brittle or stiff, since the coil is lowered from the gondola during flight and the coil's own movement can still occur later.
For the young researchers, the project, which is part of the European student program REXUS/BEXUS, offered invaluable experience: They learned the complete process of a space project, from the idea and planning to the measurement of the data, they were involved in every step. They designed the equipment and conducted various experiments. Finally, the balloon flight through icy heights lasted a good five exciting hours until the gondola was separated from the balloon and it reached solid ground again at 12:29 p.m. – in Finland. Despite the slight damage to the mechanics during the landing, the electronics were able to save the measured data; the relief in the team was great. The data is now being analyzed and will be presented at two symposia in April and May of this year. We are excited!