TRACERS: The University of Iowa Leads NASA-Funded Space Weather Research with Twin Satellites

A Q&A with Jasper Halekas

• By Mary Grush
• 08/11/25

On July 23, 2025, a NASA-funded mission led by the University of Iowa saw the successful launch of its twin satellites from Vandenberg Space Force Base space launch complex 4E, atop a SpaceX Falcon 9 rocket. The TRACERS satellites (Tandem Reconnection and Cusp Electrodynamics Reconnaissance Satellites) are carrying on-board instruments in a solar-synchronous low Earth orbit. From there, the duo will spend a year taking measurements and returning data that will help researchers as they study the increasingly critical field of space weather — in particular, the interaction of the solar wind with the Earth's magnetosphere (commonly thought of as Earth's "protective bubble").

CT spoke with Jasper Halekas, a professor in the Physics and Astronomy department at the University of Iowa and an instrument lead for the mission, about the knowledge TRACERS will bring to the science of space weather, and importantly, how students and the University of Iowa community benefit from the R1's emphasis on bringing research collaborations and academics together.

Mary Grush: Why is the TRACERS mission important to the study of space weather?

Jasper Halekas: TRACERS is a mission concerned with understanding how the energy from the sun is coupled to the terrestrial environment. We know that the sun is putting out all kinds of energy — in the form of sunlight of course, but also in the form of what we call the solar wind, a flow of hot ionized gas coming from the sun at about a million miles an hour.

When there are space weather events — solar storms and things like that — some of that energy can come into the terrestrial environment and affect our technological systems that are in orbit or sometimes even on the ground.

So, TRACERS is concerned with understanding how efficient that transfer of energy is; how much of that energy from the sun can get into the Earth's protective magnetic bubble, if you will, and affect our technological systems and consequently our society in the terrestrial environment.

Grush: Looking at the name of the mission for a minute, could you explain a little bit about magnetic reconnection? And related to that, what is the role of what is called a cusp?

Halekas: Magnetic reconnection is a process that occurs in a space plasma, that basically allows a crack to form in the Earth's magnetic field.

As you know, the Earth has a big global magnetic field produced in its core, and that magnetic field forms a kind of protective bubble around the terrestrial environment.

But that bubble can be cracked, letting energy in from the sun. Magnetic reconnection is a process that allows that to happen. It is a process where the magnetic field from the sun interacts with the magnetic field from the Earth in such a way as to open up Earth's magnetic field, letting some of the solar wind particles and energy come into the terrestrial environment.

One place that we can observe that is the polar cusp of the Earth's magnetosphere. The cusp is basically a big funnel that connects Earth's atmosphere and ionosphere out to the front of the Earth's magnetic bubble. And so, it allows us to see, in a sense, what's happening out at the very front of the Earth's magnetic shield — because everything sort of funnels down the cusp to us, and we can now observe it with TRACERS.

Grush: What kinds of measurements will TRACERS enable? And are the instruments provided by the University of Iowa as well as by other partners in the mission?

Halekas: TRACERS has a fairly complete suite of charged particle and electromagnetic field instruments on board. We measure ions, electrons, magnetic fields, and electric fields in that cusp region that we just discussed.

As examples, we have an ion instrument, which was provided by the Southwest Research Institute; a magnetic field instrument, provided by the University of California-Los Angeles; and an electric field instrument, provided by the University of California-Berkeley.

And of course the University of Iowa built several of the instruments that are on board, including an electron instrument, for which I'm the lead; a high-frequency magnetometer (a search coil magnetometer, as we call it); and a technology demonstration magnetometer called MAGIC (MAGnetometers for Innovation and Capability).

The University of Iowa also built the main electronics box, which is the central brains of the instrument suite. All of the instruments on board work together to provide the measurements we need to do the science of TRACERS.

Grush: What is the advantage of taking measurements via two satellites?

Halekas: This is really the key to the TRACERS mission. We know that the process of magnetic reconnection, that allows solar particles and energy into the terrestrial environment, is not simply a steady process that happens continuously at one location at a steady rate. We know that it changes. And with the single point measurements that we've taken previously, we're unable to determine the nature of the changes in that reconnection. We haven't been able to tell whether it is changing with time or moving around in location. So by having two measurement points (one from each of the TRACERS satellites) going through the same region in quick succession, we can actually determine whether the changes are in time or in space, or in some combination of both.

And that's really important in understanding how efficient the coupling is between the sun and the Earth.

Grush: How far apart are the two TRACERS satellites, normally, as they are working in tandem?

Halekas: The two TRACERS satellites are in essentially the same orbit around the Earth, but they're spaced slightly apart in that orbit. They're in a follow-the-leader type configuration. The time between the two spacecrafts is between 10 seconds and 120 seconds. And that translates, from tens of kilometers, to hundreds of kilometers in spatial separation.

Grush: The University of Iowa has, for a long time, had a culture of joining research with academics at all levels. In fact, the university's estimate is that one in three undergraduates participate in research programs.

How are you seeing this in TRACERS or in other research programs at the university? What are some of the opportunities and values for students who join research teams?

Halekas: We are an academic institution interested in fundamental research, but we're also invested in the education of students. So it's very important for us to have those two principal institutional missions work together.

We are an academic institution interested in fundamental research, but we're also invested in the education of students. So it's very important for us to have those two principal institutional missions work together.

Inclusion of students at all levels (graduate and undergraduate) in our research is very important to what we do here at this institution.

You mentioned that one in three undergraduates are involved in research at the University of Iowa. I assume that figure is across campus. Here in the physics and astronomy department, I would estimate that number to be even bigger; probably 50 percent or more of undergraduates in this department participate in research. And of course, all of our graduate students in the physics and astronomy department do research.

Student research is really important because at the same time that we're doing basic fundamental research, we're also training future investigators as well as technologically savvy employees and employers in various fields. And that's really important for the future of our country, I would say.

Grush: In the case of TRACERS, do the students work mostly with the instrumentation, or do they get to work in other areas of the mission? I see that Millennium Space Systems in El Segundo, now a subsidiary of Boeing, did the clean room construction of the satellites.

Halekas: The University of Iowa's role has been focused mainly on the instruments, as well as on the overall engineering effort. We did not build the spacecraft — that was built by private industry to NASA standards, by Millennium Space Systems, as you noted. We had students involved at various stages of designing and building the instruments. And a lot of times we will have students get involved in developing test apparatus, running tests, and things like that.

Once we have completed the initial commissioning of TRACERS, then we'll get students involved in analyzing data and doing the science that we propose to do.

Once we have completed the initial commissioning of TRACERS, then we'll get students involved in analyzing data and doing the science that we propose to do.

Grush: What is the LEGO project I've been hearing about?

Halekas: We had an engineering student, Ava Reed, work for a summer designing a TRACERS LEGO model. This is really amazing. The model looks so true to life. It includes all of the instruments and all the basic components of the spacecraft.

The model is totally open source and public, so anybody can take the source files and order the pieces. We provide the instructions to put it together. If someone is looking for a stocking stuffer or a great gift, it's a pretty cool LEGO set.

Grush: Some of the instruments and lab environments required by research programs at the university are very advanced technologically. Are there any significant hurdles in providing this kind of technology infrastructure in order to maintain the high R1 research profile that the university enjoys? How do you approach that?

Halekas: This is absolutely the big challenge for R1 universities who want to be involved in things like this, because there is a lot of specialized infrastructure that is required, to be involved in building and testing things for a NASA mission. This, of course, is not exclusive to space research. It's true of a lot of areas of research, especially in the sciences.

I think it's a broad challenge for academic institutions, because it is often the case that grants and contracts cannot directly fund the infrastructure that you need to do these projects. So that requires institutional investment to allow us to have the infrastructure to propose and do these projects.

We've been very lucky working in research here at the University of Iowa. We've gotten a lot of support for research programs from our institution, and the institution has put a lot of effort and funding into building up the infrastructure and the specialized facilities that we need to build and test these very complex science instruments that we're creating and launching into space.

The institution has put a lot of effort and funding into building up the infrastructure and the specialized facilities that we need to build and test these very complex science instruments that we're creating and launching into space.

Grush: Is there a trend towards miniaturization in spacecraft and on board instruments, and how is that affecting your work? For example, I've heard it said that what is a refrigerator-sized satellite today, might someday be more like the size of four loaves of bread.

Halekas: There is definitely a trend towards miniaturization of spacecraft and spacecraft instrumentation. One reason for that is, every kilogram of mass that you want to launch into orbit costs some large amount, so the smaller you can make something, the easier it is to launch it into orbit.

And there has been a lot of work in recent years on developing launch opportunities for very small payloads. One thing that has been happening a lot is that programs have been launching what are called CubeSats, small spacecraft about the size of a toaster. Another category is called SmallSats, which generally aren't quite as small as CubeSats but follow a standard form factor. And there are standardized launch capabilities for these small payloads.

There were several rideshare experiments that were launched along with TRACERS. They were in the CubeSat class of very, very small spacecraft. Each of the TRACERS satellites is about the size of a compact washing machine, so while they're not CubeSat-sized, they're not very big.

Grush: Related to that, are there any implications for environmental or ecological concerns? You know, we're putting a lot of stuff up in low Earth orbit. It seems to me it would get a little crowded out there.

Halekas: The proliferation of space junk is definitely a concern. There are certain altitudes that are getting very crowded with space debris. And there are also lots of working satellites and spacecraft in orbit now, which can become a problem for astronomers. So for our NASA-funded science investigations, we have requirements that our payloads have to deorbit within a certain amount of time. And most of the objects we're talking about are small enough that they will completely burn up on reentry. A little CubeSat or even something TRACERS-sized will generally break apart and burn up on the way down.

Grush: Especially given the collegial environment for TRACERS and other research projects led by the University of Iowa, is there a priority for open science? Will the research results and data be made available to the world?

Halekas: Open science is an important priority for NASA and for science as a whole in our country these days. And TRACERS is absolutely following that open science model. So we have, as you may know, a couple months here at the start of the mission to get the instruments commissioned and make sure that our data are well calibrated [by applying the instrument calibrations to the data]. But after that, we'll make all of the data available to the public at a very quick cadence.

Open science is an important priority for NASA and for science as a whole in our country… We welcome the scientific community to utilize our data to do science.

And within a month of the receipt of data, the basic data products will be made public though two channels: The Science Operations Center (SOC) here at the University of Iowa, and the NASA Space Physics Data Facility (SPDF).

We welcome the scientific community to utilize our data to do science. The more people looking at our data and doing science with it, the better the outcome from the mission. So we consider it highly desirable to have people from outside the TRACERS team using the data.

Grush: The University of Iowa has a rich history in space science and astrophysics research. And at the initially reported funding level of $165.7million — nearly $166million — TRACERS is considered the largest-single externally funded research project in the history of the university. What are some of your hopes for research at the University of Iowa as an R1, especially in space science, going forward?

Halekas: The University of Iowa is a really great place to work, especially if you're interested in space, because, in a very real way, the space age started here at the University of Iowa, with James Van Allen launching his experiment on Explorer 1. Space science has continued to be an important part of what we do at the University of Iowa ever since.

As you may know, the university has been involved in all sorts of space missions over the years and decades, from Voyager 1 and 2 — which have traveled the outer reaches of our solar system — to missions to Venus, Mars, Saturn, Jupiter, and more… So, you're right, there's a rich history here, of research going back all the way to the very start of space physics, and TRACERS is the latest part of all that. TRACERS is a really important mission for us because the University of Iowa is the lead institution, and there's a lot of support for research associated with that.

And TRACERS is an especially good example of how NASA, academic institutions, and private industry can all work together to accomplish something really awesome.

TRACERS is an especially good example of how NASA, academic institutions, and private industry can all work together to accomplish something really awesome.

Hopefully for us TRACERS is just one in a long series of missions. And we're hoping, especially with the team and the infrastructure that we've established here and that we've used for TRACERS, that we'll be able to continue doing these kinds of missions going forward, far into the future.

Grush: And in the near term you've got an interesting year ahead of you with all the data you're going to be seeing from TRACERS.

Halekas: Absolutely. We can't wait.

[Editor's note: For updates and more information on the TRACERS mission and science, visit NASA's TRACERS page.]