NASA’s Tandem Reconnection and Cusp Electrodynamics Reconnaissance Satellites mission, or TRACERS mission, has passed a critical mission review on March 31, 2022. The mission now moves into its next phase, advancing towards its target launch readiness date of July 27, 2024.

“We’re excited to pass this major milestone and get one step closer to launch,” said Prof. Craig Kletzing, space physicist at the University of Iowa in Iowa City and the mission’s principal investigator.

The review, Key Decision Point C, evaluated the mission’s preliminary design and program plan to achieve launch by its target launch readiness. With the successful review, TRACERS now moves into Phase C, which includes the final design of the mission and building of the two satellites.

“TRACERS will be an important addition to our heliophysics fleet,” said Washito Sasamoto, program executive for the mission at NASA Headquarters in Washington, D.C. “The mission is targeting long-standing questions critical to understanding the Sun-Earth system.”

TRACERS is a pair of satellites that will study how the solar wind, the continuous stream of ionized particles escaping the Sun and pouring out the space, interacts with Earth’s magnetosphere, the region around Earth dominated by our planet’s magnetic field. The linchpin of that interaction is the phenomenon of magnetic reconnection, an explosive transfer of energy that can happen when two magnetic fields meet.

Magnetic reconnection happens all throughout space but is of special relevance where the solar wind first meets Earth’s magnetosphere, a region known as the magnetopause. A reconnection event can shoot solar wind particles, normally diverted around our planet, directly into our atmosphere at high speeds. These particles ignite the beautiful northern and southern lights but also create potentially hazardous conditions for astronauts and sensitive satellites.

To study magnetic reconnection at Earth’s magnetopause, TRACERS will fly through the polar cusp, a point where Earth’s magnetic field dips down toward the ground. There, particles funnel through the cusp into a concentrated part of our atmosphere.