Way up in space, the Sun isn’t just glowing, it’s throwing. Fast-moving particles slam into Earth’s upper atmosphere, triggering dramatic bursts of energy through a mysterious process called magnetic reconnection. These invisible explosions can unleash more power than the U.S. burns in a whole day.
Enter TRACERS: NASA’s Space Detective Duo
NASA’s TRACERS mission is sending twin satellites to investigate these wild space events. Their goal? To uncover how solar outbursts influence space weather, the invisible forces that affect satellites, power grids, and even radio signals down here on Earth.
NASA’s TRACERS mission is set to blast off in late July 2025 aboard a SpaceX Falcon 9 rocket from California’s Vandenberg Space Force Base.
After launch, the two spacecraft will orbit Earth to study how the solar wind, streams of charged particles from the Sun, interacts with Earth’s magnetic shield, known as the magnetosphere.
Earth’s magnetic field is gradually weakening
The Sun doesn’t just shine, it streams. Solar wind, a fierce mix of charged particles and tangled magnetic fields, races through space at over a million miles per hour, smacking into anything in its path.
Luckily, Earth has a guardian: the magnetosphere. Think of it as a floating cosmic shield, like a bar magnet spinning around in space, repelling most of the Sun’s fury. But when solar wind pressure builds, magnetic field lines can snap and whip particles away in explosive bursts; this is magnetic reconnection, one of space’s most powerful fireworks.
At Earth’s poles, the shield has entry points called polar cusps, funnel-shaped openings where particles pour in and crash into the atmosphere, painting the skies with auroras and, sometimes, chaos.
In May 2024, Earth got a taste of solar drama:
- The biggest geomagnetic storm in 20+ years
- Flights rerouted, power systems scrambled
- GPS-guided tractors lost track of the field
The two satellites of the TRACERS mission will fly “concurrently”, one after the other, in a relatively low orbit about 360 miles above Earth. They will travel at speeds exceeding 16,000 mph, equipped with a suite of instruments to measure various aspects of plasma and its interaction with Earth’s magnetosphere.
When the solar wind hits the magnetosphere, some energy waves …
The satellites will explore where Earth’s magnetic field descends to the ground at the North Polar Cusp. The satellites will be placed in a Sun-synchronous orbit, and they will always pass through Earth’s dayside polar cusp, studying thousands of reconnection events at these concentrated areas.
NASA’s twin TRACERS satellites aren’t just flying in circles; they’re dancing through Earth’s dayside polar cusp, a sweet spot where the planet’s magnetic field dips and solar particles stream in. By orbiting in sync with the Sun, TRACERS will repeatedly pass through this energetic gateway, capturing thousands of magnetic reconnection events in real time.
Why This Matters
This mission will stitch together a dynamic timeline of how magnetic reconnection evolves, not just across days, but from sunrise to starlight. It’s a leap beyond earlier snapshots, like the 2018 TRICE-2 mission, which launched short-term rockets over the Norwegian Sea and captured single moments.
“TRICE showed we could measure these effects,” said David Miles of the University of Iowa. “TRACERS shows we can track how they change.”
A method to study mini-magnetospheres
Previous missions could only grab a single snapshot of a space weather event, like trying to understand a thunderstorm from one lightning bolt. Too much was changing, too fast.
Enter NASA’s TRACERS satellites, flying in tandem like synchronized swimmers in space. Spaced just 10 seconds apart, they’ll capture multiple snapshots of the same stormy region, building a fluid, frame-by-frame view of how Earth’s magnetic shield reacts to the solar wind’s punch.
In one year, they’ll gather over 3,000 measurements, stitching together a time-lapse of how space weather unfolds around our planet. Scientists will finally be able to observe the magnetosphere as a dynamic system, rather than a static moment, improving predictions and paving the way for smarter safeguards against geomagnetic disruptions.
NASA’s new mission, TRACERS, isn’t going it alone; it’s joining a stellar squad of spacecraft across the solar system to better understand the Sun’s magnetic mood swings.
Early magnetic field around Earth was even stronger than previously believed
At the heart of it all is the Parker Solar Probe, which gets up close and personal with the Sun, tracking how magnetic reconnection heats and speeds up the solar wind, the very stuff TRACERS watches as it hits Earth.
Back at home, TRACERS taps into data from:
- EZIE, which studies electric currents on Earth’s nightside
- PUNCH, which keeps an eye on solar wind and its dance with Earth’s atmosphere
Together, this space fleet is building a clearer picture of how Earth’s magnetic shield opens up and lets solar particles stream in, sometimes lighting up the skies with auroras, and at other times interfering with satellites and power grids.
“TRACERS is a vital new piece of the puzzle,” says NASA’s Reinhard Friedel. “Combining forces across missions helps us predict and prepare for space weather impacts on our planet and our tech.”
The mission is led by David Miles from the University of Iowa, with instruments built by teams across Texas and California. From launchpads in Florida to space labs around the country, TRACERS is supported by NASA’s heliophysics experts and the VADR launch program.