Field Emission Cathodes for an Electrodynamic Tether Experiment on the H-II Transfer Vehicle.

A field emission cathode (FEC) using a carbon nanotube was developed for an electrodynamic tether experiment on H-II transfer vehicle 6 (HTV-6). The mission is called the Kounotori Integrated Tether Experiment (KITE). Development of the FEC began at the beginning of 2013 and was completed in the spring of 2016. KITE began in January 2017 and the FEC worked well, with various types of on-orbit data being obtained despite unsuccessful tether deployment. All eight cathode units operated without any critical trouble throughout the experiment period. The total operation time reached 50 hours and the maximum emission current was approximately 5.8 mA, and thus exceeded expectations based on ground experiments. The electrical current loop via an ambient space plasma without the tether was probably formed due to the collection of electrons on the anodic parts of the HTV's solar cells. [ABSTRACT FROM AUTHOR]