1. Te Pūnaha Ātea - Auckland Space Institute, Department of Physics, The University of Auckland 1 , Auckland 1010, New Zealand
2. Space Plasma, Power and Propulsion Laboratory, Research School of Physics, The Australian National University 2 , Canberra, ACT 2601, Australia
3. Department of Mechanical Engineering, University of Canterbury 3 , Christchurch 8140, New Zealand