TRACERS

Tandem Reconnection and Cusp Electrodynamics Reconnaissance Satellites

future Mission

In this artist's concept, the two TRACERS spacecraft are orbiting above Earth. Earth fills most of the image, with speckles of a starry sky visible above the planet. The spacecraft are octagonal with long antennae sticking out on four sides, and shorter antennae sticking out on two sides.

TRACERS will help understand magnetic reconnection and its effects in Earth’s atmosphere. Magnetic reconnection occurs when activity from the Sun interacts with Earth’s magnetic field. By understanding this process, scientists will be able to better understand and prepare for impacts of solar activity on Earth.

Mission Type

Twin Satellites

FOCUS

Magnetic Reconnection

Launch

April 2025

Landing

Low Earth Orbit

TRACERS Will Study How Space Weather Impacts Earth

Earth’s magnetosphere protects the planet from the constant bombardment of solar particles from the Sun, called the solar wind. Magnetic reconnection occurs when the solar wind interacts with the magnetosphere, causing magnetic field lines to disconnect and reconnect. This causes particles to rain down into Earth’s atmosphere. The effects of space weather can lead to beautiful phenomena, like the aurora, but can also impact space-based infrastructure, like satellites and GPS systems.

By placing the twin TRACERS spacecraft in Sun-synchronous orbit, so that they always pass through the Earth’s dayside, the team will accumulate thousands of dayside reconnection events. Since there are two spacecraft, scientists will be able to observe how quickly the process changes and evolves by comparing the data collected by each spacecraft.

Animated graphic showing solar wind blowing against giant magnetic bubble surrounding Earth, with two funnels in the bubble at the north and south poles

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.

NASA/CILab/Josh Masters

Collaborations Across Missions

The TRACERS mission team will work with other missions that study complementary regions and processes. NASA’s Magnetospheric Multiscale Mission (MMS) studies magnetic reconnection from out in space. TRACERS observations from low Earth orbit will enable scientists to compare the results from the two missions.

Future missions, like NASA’s Polarimeter to Unify the Corona and Heliosphere (PUNCH) and Electrojet Zeeman Imaging Explorer (EZIE) mission, will also be in low Earth orbit, studying the solar wind and interactions in Earth’s atmosphere. By combining observations from PUNCH, EZIE, and TRACERS, scientists will be able to get a more complete understanding of how energy from the Sun’s atmosphere flows through Earth’s magnetosphere and atmosphere.

TRACERS is led by David Miles at the University of Iowa and managed by the Southwest Research Institute in San Antonio, Texas. NASA’s Heliophysics Explorers Program Office at NASA’s Goddard Space Flight Center in Greenbelt, Maryland provides mission oversight to the project for the agency’s Heliophysics Division at NASA Headquarters in Washington, D.C. The University of California, Los Angeles and University of California, Berkeley, lead instruments on TRACERS that study changes in the magnetic field and electric field.