Observing Cusp High-Altitude Reconnection and Electrodynamics: The TRACERS Student Rocket

Abstract

Observing Cusp High-altitude Reconnection and Electrodynamics (OCHRE) is a student/early career researcher (ECR) focused sounding rocket that will fly as a compliment to the TRACERS satellites. OCHRE will utilize the deep institutional knowledge of the TRACERS science team to educate and mentor a team of graduate students and ECRs to serve as instrument leads, project manager, and primary investigator. Aiming for a near conjunction with, and at an apogee above, TRACERS in the northern polar cusp, OCHRE will answer some remaining questions from the TRICE-II sounding rockets using TRACERS to contextualize observations in the larger-scale polar cusp dynamics.

Keywords: Cusp; Sounding rocket; Student; TRACERS.

Fig. 1

Observations from the TRICE-II High Flyer; A) omni-directional ion energy flux, B) omni-directional electron energy flux, C) electric field Power Spectral Density. The first box highlights the observation of mirroring magnetospheric particles, and the coincident broad band wave features, see Sect. 2.1. The second box highlights the onset of ion outflow, and again the coincident broad band wave features, see Sect. 2.2. The red dotted line marks the open/closed field line boundary (OCB). Adapted from Sawyer et al. (2021)

Fig. 2

A diagram of a ‘Pressure Cooker’ scenario. The BBELF waves act to transversely heat ambient ions, while the very cold ions get forced to lower altitudes. These transversely accelerated ions (TAIs) eventually escape the parallel electric field where they would be observed as ion upflow. Adapted from Shen et al. (2018)

Fig. 3

The common pathways of cusp outflows, from direct energy deposition from the solar wind. As observed from FAST satellite observations. Here r is the calculated correlation coefficient between related observations. Provided by R. J. Strangeway, adapted figure from Strangeway et al. (2025). This figure includes the correlation coefficients for the Alfvén-wave related scaling laws presented by Brambles et al. (2011)

Fig. 4

A simulated electron dispersion feature binned from 14.2-14.4 magnetic local time

Fig. 5

Cutaway view of CuEDI. A radial electric field guides electrons of appropriate energy through the optics to an MCP assembly, which then deposits a measurable charge on detection anodes. Adapted from Halekas et al. (2025)

Fig. 6

Instrumentation mounting and location diagram aboard OCHRE

Fig. 7

Cutaway view of SACI. The ion trajectory enters the collimator and ions with appropriate energy per charge traverses the ESA gap and strike the microchannel plate (MCP) detector. The signal is amplified by the front-end electronics (FEE) and then transmitted to be processed onboard the rocket e-box. Adapted from Fuselier et al. (2025)

Fig. 8

Functional block diagram of the OCHRE Fields suite showing the EFI, commercial Mag, and FEB. Courtesy of R. A. Hochman

Fig. 9

Detailed view of the racetrack core shape with the copper sense windings. Adapted from Greene et al. (2022)

Fig. 10

(A) The tesseract sensor flown aboard the ACES-2 sounding rocket, with the racetrack core placement and housing shown. Similar in design to MAGIC, to be flown aboard the TRACERS spacecraft. Also note the 4 coil (Merritt) feedback winding. Adapted from Greene et al. (2022). (B) 3D model of MiniTs to be flown aboard OCHRE. Note the added external electronics, the single core per axis, and the two coil feedback winding

Fig. 11

Noise and power consumption associated with different alloy ratios for racetrack geometry ring cores. Adapted from Narod and Miles (2024)

Fig. 12

The OCHRE team organizational structure and defined roles

Fig. 13

The OCHRE science traceability matrix. Defines the instrument requirements necessary for closure of the proposed science questions, and the actual instrument performances