Design and test in microgravity of a space tether length and length rate measurement device

Abstract—In this paper design, implementation, laboratory and microgravity tests of a space tether length and length rate measurer are discussed. The instrument presented was part of an experimental setup consisting in a new concept of space tether deployer with retrieval capability, which was designed and built in the framework of the Drop Your Thesis! 2016 educational programme, held by the European Space Agency Education Office. The instrument working principle is based on optical sensors and is inspired to similar instruments used on SEDS and YES2 space missions. The entire setup was first tested in laboratory on a low friction rail, then in microgravity conditions at the ZARM Drop Tower. The results of the test campaign proved the functionality of the measurement instrument which allowed the experiment to meet the prefixed goals.