NASA’s TRACERS Spacecraft Begin Preliminary Science Data Collection

NASA’s TRACERS (Tandem Reconnection and Cusp Electrodynamics Reconnaissance Satellites) mission has started collecting preliminary science data, including tandem measurements that are key to the mission’s science goals. One of the two satellites, Space Vehicle 2, completed commissioning and is fully operational. The other satellite, Space Vehicle 1, is also operating with some limitations following an issue earlier this summer that caused intermittent contact with the spacecraft.

The TRACERS mission launched on July 23, from Vandenberg Space Force Base in California. Following successful signal acquisition from Space Vehicle 2, the satellite underwent a commissioning period where mission controllers ensured the satellite is healthy, communicating properly, and in proper orbital position. 

The mission team conducted recovery efforts for the other spacecraft when an issue with the power subsystem resulted in a loss of communication with Space Vehicle 1. Once communication was re-established, the mission team oriented the spacecraft towards the Sun to an angle that allowed the solar panels to generate more power. All data indicates that the battery on Space Vehicle 1 is no longer functioning properly, so the vehicle will always need to receive sufficient sunlight to power its systems during active science data collection.

With these parameters, the mission team re-targeted the mission’s science data collection to focus on Earth’s southern polar cusp, rather than the northern polar cusp as was originally planned. This allows Space Vehicle 1 to collect sunlight and power up its systems on Earth’s dayside before it reaches its target area, maximizing the science data that the satellite can collect on each orbit. 

“The TRACERS team, together with their spacecraft operators at Millennium, need to be commended for their outstanding efforts in starting science data collection with Space Vehicle 1,” said Reinhard Friedel, TRACERS program scientist at NASA Headquarters in Washington. “This has re-established a path for TRACERS as it works to achieve its original science goals that require tandem observations in the Earth’s cusps.”  

Both spacecraft are now collecting limited, routine tandem measurements at Earth’s southern polar cusp with multiple instruments to understand how particles from space stream into our planet’s atmosphere during space weather events. Full assessment of the impacts to the mission’s science goals continues as the mission team develops a new operational plan to commission the instruments on Space Vehicle 1 within the new mission constraints.

The TRACERS mission launched to study magnetic reconnection and its effects in Earth’s atmosphere. Magnetic reconnection occurs when the Sun’s magnetic field is embedded in continuous outpouring of electrical charged particles, or solar wind, and collides into Earth’s magnetic shield. This interaction builds up energy that can cause the magnetic field lines to snap and explosively fling away nearby particles at high speeds directly into our atmosphere.

Understanding magnetic reconnection and space weather will help scientists better predict geomagnetic storms and the effects of other space weather phenomena that can affect the safety of astronauts as well as power grid and communication systems.

NASA will provide additional updates online at: 

https://science.nasa.gov/blogs/tracers

The TRACERS mission is led by David Miles at the University of Iowa with support from the Southwest Research Institute in San Antonio. NASA’s Heliophysics Explorers Program Office at the agency’s Goddard Space Flight Center in Greenbelt, Maryland, manages the mission for the agency’s Heliophysics Division at NASA Headquarters in Washington. The University of Iowa, Southwest Research Institute, University of California, Los Angeles, and University of California, Berkeley, all lead instruments on TRACERS that will study changes in Earth’s magnetic field and electric field. 

By Desiree Apodaca
NASA’s Goddard Space Flight Center, Greenbelt, Md.

December 12, 2025