Spacecraft completed for NASA’s TRACERS mission, key milestone passed

The twin spacecraft of NASA’s TRACERS (Tandem Reconnection and Cusp Electrodynamics Reconnaissance Satellites) mission were recently completed, in preparation for launch in 2025.

The TRACERS mission is a pair of satellites that will study how the solar wind, the continuous stream of ionized particles escaping the sun and pouring out into space, interacts with Earth’s magnetosphere, the region around Earth dominated by our planet’s magnetic field. The mission will help answer key questions about how the sun influences Earth, and ultimately drives space weather that impacts technology and communications.

Specifically, TRACERS will study the phenomenon of magnetic reconnection, an explosive transfer of energy that can happen when two magnetic fields meet.

Magnetic reconnection happens throughout space but is of special relevance to us 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, known as aurora, and help drive space weather on Earth.

Understanding space weather patterns is paramount in our increasingly technologically driven society, as space weather events can affect our power grids and communications satellites, and create potentially hazardous conditions for astronauts.

To study magnetic reconnection at Earth’s magnetopause, TRACERS’ twin satellites will fly in tandem—one behind the other—through the polar cusps, funnel-shaped regions where Earth’s magnetic field opens over the north and south poles. This will allow scientists to observe how quickly reconnection changes and evolves by comparing data collected by each satellite.

Millennium Space Systems, a Boeing company, finished building the two satellites for the TRACERS mission in October 2024. The team is completing integration of the TRACERS instruments, and the two satellites will enter the testing phase. Once testing is completed, the spacecraft will be shipped to Vandenberg Space Force Base in California for integration with the launch vehicle.

“It’s exciting to see the TRACERS instruments and the two spacecraft come together. The team is making excellent progress toward launch,” said David Miles, TRACERS principal investigator at the University of Iowa in Iowa City.

In addition, the mission successfully passed a critical review, called Key Decision Point D, on Aug. 8, 2024, preparing TRACERS to achieve a target launch readiness date no earlier than April 2025. With the successful review, TRACERS moved into Phase D, the official transition from the mission’s development stage to the delivery of the spacecraft, testing, assembly, and integration into the launch vehicle in preparation for launch.

“This team has been truly incredible,” says Skyler Kleinschmidt, TRACERS program executive at NASA Headquarters in Washington. “Building a spacecraft is never easy, but seeing the team work together through all of the challenges that they have encountered is inspiring.