EZIE satellites begin mission to map Earth's auroral electrojets

EZIE satellites begin mission to map Earth's auroral electrojets
by Clarence Oxford
Los Angeles CA (SPX) Mar 17, 2025

NASA's Electrojet Zeeman Imaging Explorer (EZIE) mission is now in space and preparing to study powerful electric currents in Earth's upper atmosphere following a successful launch and satellite deployment. Liftoff took place at 11:43 p.m. PDT on March 14, 2025, from Vandenberg Space Force Base in California, with the deployment of all three CubeSats completed around 2 a.m. PDT the next day.

In the next 10 days, the EZIE spacecraft trio will transmit signals back to mission control to confirm their operational status. These satellites will fly in low Earth orbit at altitudes between 260 and 370 miles (420 to 590 kilometers), gathering data on auroral electrojets - intense currents that flow through the polar atmosphere where auroras appear. Insights from EZIE aim to refine space weather models, helping reduce the risks posed by geomagnetic storms to satellites, power grids, and communication networks.

EZIE represents the first dedicated mission to explore these currents, which can carry up to one million amps around the polar regions at about 65 miles (100 kilometers) above Earth. To capture these phenomena, each suitcase-sized CubeSat carries a Microwave Electrojet Magnetogram instrument that detects magnetic signatures of electrojets by measuring microwave emissions at 118 gigahertz from oxygen molecules situated roughly 10 miles (16 kilometers) below the currents.

As they orbit from pole to pole, the three EZIE satellites will maintain formation using controlled drag techniques rather than propulsion. By adjusting their orientation, each satellite can vary the atmospheric drag it experiences, enabling the trio to maintain separations that allow sequential observations of the same region minutes apart. This setup permits the team to track how electrojets change over time.

During each orbit, every satellite will generate a detailed map of the auroral electrojets' structure. When combined, these maps will illustrate the evolution of these currents, shedding light on how Earth's magnetic environment interacts with near-Earth space. The mission's results will not only improve our understanding of Earth's space environment but also enhance knowledge applicable to other magnetized planets.

Led by the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, the EZIE mission is managed by NASA's Goddard Space Flight Center under the agency's Heliophysics Division. Blue Canyon Technologies in Boulder, Colorado, built the CubeSats, while NASA's Jet Propulsion Laboratory developed the microwave instruments onboard. The mission launched aboard a SpaceX Falcon 9 rocket as part of the Transporter-13 rideshare managed by Maverick Space Systems.

EZIE's mission duration is planned for 18 months. As part of public engagement efforts, the mission team is distributing EZIE-Mag magnetometer kits to schools and citizen scientists across the U.S. Data from these ground-based instruments will complement the satellite observations, helping construct a comprehensive picture of Earth's space current system.