Operation of a carbon nanotube field-emission cathode in low Earth orbit

A carbon nanotube-based field-emission cathode (FEC) has been researched and developed by the Japan Aerospace Exploration Agency mainly for space-debris removal systems with electrodynamic tether (EDT) propulsion. An in-orbit experiment to demonstrate the EDT technologies including the FEC was planned and conducted in early 2017. The FEC operated well without any critical trouble during the one-week mission period. The data obtained include its electron emission capability to space plasma and its durability in low Earth orbit, which suggest the prospect of using the FEC in space.