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From a launch pad at the Vandenberg Space Force Base in California, physics and astronomy professor watched as NASA’s latest mission soared into the sky. The ever-smaller dot capped years of planning, design, construction, and logistics organized from ���㽶��Ƶ for a team spread across the United States. 

Now, the Relativistic Electron Atmospheric Loss satellite carries the promise of providing new insights into the interaction between plasma waves and the high-energy particles in the bands of radiation surrounding Earth known as Van Allen belts. The launch represents a technical achievement in its own right, and it also marks the start of an important mission to better understand the space environment that surrounds our planet.

Millan is the principal investigator for REAL, which hitched a ride July 23 aboard a SpaceX Falcon 9 rocket with the launch’s main payload, a dual-satellite mission known as Tandem Reconnection and Cusp Electrodynamics Reconnaissance Satellites. TRACERS will study the daytime magnetic shield—or magnetosphere—that protects Earth from the stream of supercharged particles flowing from the sun known as solar wind.

, professor of physics and astronomy, is a science co-investigator for TRACERS. He co-authored the original proposal laying out the scientific objectives and consulted with the teams building the twin satellites on how to scientifically optimize their design.

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The shoebox-sized satellite for the ���㽶��Ƶ-led REAL mission is put into orbit, where it will collect data for at least six months. (Photo by SpaceX)

Once TRACERS is fully online, LaBelle will participate in data analysis related to the mission’s main objective: understanding how the magnetosphere “reconnects” on the Earth’s dayside, where it plays a significant role in the planet’s interaction with the sun. Building on his research focus, LaBelle will lead an investigation of plasma waves detected by TRACERS through fluctuations in Earth’s electric and magnetic fields. 

TRACERS is inspired by two sounding-rocket experiments, TRICE and TRICE-2, on which LaBelle was a lead investigator. These missions proved the concepts behind TRACERS using instruments built by ���㽶��Ƶ students and engineers for measuring electric fields and plasma waves. 

“My career has been dedicated to study of plasma waves, both measured directly in space using sounding rockets and measured remotely using ground-based instruments,” LaBelle says. “TRACERS is a powerful platform to continue both types of studies.”

REAL, the mission led by Millan, went into space as part of NASA’s program for small research spacecraft, known as CubeSats, that are selected to fly alongside primary launch missions. Of the 200 CubeSats selected to date, REAL—which is a foot long and weighs less than 10 pounds—is the first from ���㽶��Ƶ.

The tiny satellite and its even smaller instrument are specifically designed to characterize the loss of particles from Earth’s Van Allen belts, which are two donut-shaped rings of high-energy charged particles in near space, Millan says.

Millan has been leading a team of scientists and engineers since 2017, developing REAL’s science objectives, overseeing major science and engineering decisions, and managing all communications with NASA and mission launch providers. The project endured extended slowdowns due to the COVID-19 pandemic, launch delays, and personnel turnover. 

Through all of it, Millan worked to keep the project focused, coordinating calls and logistics with multiple researchers around the country. 

“It was a real team effort, but I think what I contributed was the direction and cohesion,” Millan says. “I was pushing the team and making sure they were communicating, and helping find solutions and making decisions when we found a problem. I also advocated for our project and got us assistance when needed.”

“The job of any principal investigator is to trust their team, facilitate communication, and make sure everyone’s ideas are heard, but also to be willing to step in to guide, challenge, or make decisions. For this project, some of what was needed was boosting team morale so people would believe we could make it to the end.” 

Particles in Earth’s Van Allen belts travel at nearly the speed of light along magnetic field lines in the radiation belts. When fast-moving electrons in the belt interact with plasma waves, they can spiral down close enough to collide with Earth’s atmosphere and ultimately be lost from the radiation belts. This electron loss can happen very quickly— sometimes in bursts as short as 100 milliseconds.

The key piece of instrumentation is a small but powerful particle detector that fits inside the CubeSat and will observe electron loss in Earth’s radiation belts. The first-of-its-kind instrument was built by the Johns Hopkins Applied Physics Lab in Laurel, Maryland. It was a feat of engineering to design such a small device that is capable of multiple directions of observation and can detect energies in three orders of magnitude, Millan says.

The REAL CubeSat itself was produced by scientists and engineers at Montana State University, who also conducted extensive testing to make sure it could survive the launch and the harshness of space.

At ���㽶��Ƶ, student and staff researchers in Millan’s lab developed computer models for early vibration testing and conducted orbital debris and thermal analyses. After launch, her lab will be closely involved in the analysis and sharing of REAL’s data, which the satellite will collect for at least six months.

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Physics and astronomy professor Robyn Millan, center, and the team on the Relativistic Electron Atmospheric Loss project at the launch site. (Photo courtesy of Robyn Millan) 

Millan and her collaborators hope to shed light on both the physical process that scatters particles into the atmosphere and be able to better quantify how many particles are being lost to the atmosphere from the radiation belts.

Understanding the microphysics of these interactions is important because of the heavy reliance on satellites that move through the region of the Van Allen belts. For example, GPS satellites help drivers navigate, aid in planting crops, and provide precision timing for many industries. These satellites can be damaged by high-energy particles in the Van Allen belts. 

From low-Earth orbit, REAL will point this instrument along Earth’s magnetic field to, for the first time, take very rapid measurements of radiation belt electrons as they enter the atmosphere. By measuring how frequently these particles fall, what angle relative to the magnetic field lines they fall at, and how energetic they are, REAL will improve our understanding of their microphysics, Millan says. 

“Other experiments have measured the particles directly, but REAL is the first to make high-time resolution measurements of their full energy and angular distribution,” Millan says. “This is necessary to resolve all the information we have about these very fast bursts of electrons that rain down on the atmosphere.”