R. P. Sawyer

The launch of the Twin Rockets to Investigate Cusp Electrodynamics‐2 (TRICE‐2) took place on the morning of 08 December 2018. The two rockets of this campaign each sampled the low‐altitude Northern Hemisphere cusp region at approximately the apex of each rocket's trajectory (1,042 and 757 km for the High flyer and Low flyer, respectively). Ion and electron electrostatic analyzers (ESAs) on board each rocket measured in situ particle populations throughout the flights. Energy‐flux spectrograms of ions and electrons from each ESA clearly show the passage of each rocket through the cusp region. This work examines the locations of these entrance/exit points in relation to cusp models as provided in and compiled from the published literature, along with a discussion of model variables that have been optimized to best fit the cusp region boundary sampling locations by TRICE‐2. The results of this study set the stage for understanding the upcoming NASA Small Explorer Tandem Reconnection and Cusp Electrodynamics Reconnaissance Satellites orbital plane intersections with (i.e., “trajectory cuts” through) the cusp region.