Mines team awarded $2.5M to help build a NASA balloon experiment to investigate high energy cosmic rays, neutrinos

High above the Earth, particles from space hit the atmosphere and explode in showers of billions of particles. Physicists have studied these cosmic rays for decades – but still do not know where they come from or what happens in these explosions. 

An international research project -- in which Colorado School of Mines is a key partner -- hopes to observe these particles from high in the Earth’s atmosphere to better understand where they come from and how they interact.

Eric Mayotte, assistant professor of physics at Mines, is one of the leads on the interdisciplinary project, which will involve launching a super-pressure balloon carrying 3,000 pounds of telescopes and radio antennas to capture information on high energy cosmic rays and neutrinos more than 18 miles above the Earth. 

Mines is one of 10 U.S. universities involved along with 15 international institutions. The project is being funded by NASA, with Mines receiving a $2.5 million award to support the team’s work.

Ultra-High-Energy cosmic rays are the most energetic things that scientists know of in the universe, Mayotte said, and this mission could result in the first optical observation of them from above. Currently, the only optical observations of these rarely seen particles have come from Earth-based observatories, and some of the physics the Mines team will be investigating is often only studied at much lower energies in human-made particle accelerators, such as the Large Hadron Collider in Switzerland, the largest particle accelerator in the world. 

But studying these particles and their interactions near where they hit the atmosphere can yield more information than researchers can get in those human-made environments or at ground based observatories, he said.

“The first few particle interactions are higher in energy than anything we can produce on Earth, like in an accelerator,” Mayotte said. “If we can see these first few interactions, we have a good chance of doing some really interesting particle physics work.”

The project, named POEMMA Balloon with Radio, is intended as a pathfinder mission for an eventual NASA observatory called Probe of Extreme Multi-Messenger Astrophysics, or POEMMA. POEMMA will consist of twin satellites that can measure the highest energy phenomena in the universe. This is the third pathfinder mission for POEMMA, with specific emphasis this time on proving that the technology and measurement strategies needed for the satellite mission are ready.

“We have bigger observatories, like the Pierre Auger Observatory, that sit on the ground that have been working for 20 years,” Mayotte said. “But what we want to see is how well we can measure from above, how well we can extract critical information on these cosmic particles, like where they came from, what they’re made of and what their energy is like. If we can show that we can do a very good job doing that from the top of the atmosphere, then that means we’ll be able to do a good job from space. And if we put one of these telescopes in space, the amount of atmosphere we’ll be able to observe means that, functionally, we’ll have an observatory that is at least 10 times bigger than anything that exists on the ground.”

Most of the equipment for the project, including much of the telescopes, power system, radio support and field test structures and instruments, will be fabricated at Mines. Specifically, the Mines team will lead:

• The mechanical design of the entire payload the balloon will carry, as well as the payload’s integration, calibration and field testing.
• The designing and building the telescopes.
• The design, building and testing of the rotation mechanism that gives the telescopes on board the ability to look up toward the stars or down toward the atmosphere in partnership with the University of Chicago.
• The design of the power system.
• Co-leading the balloon’s tests in Delta, Utah, and Palestine, Texas, as well as eventual launch in Wanaka, New Zealand, scheduled for 2027.
• Leading the development of machine learning analysis techniques to be used on the data gathered by the optical telescopes.

In addition to Mayotte, the Mines team includes Lawrence Wiencke, a professor of physics who has worked on similar super balloon projects; Fred Sarazin, professor and department head of physics; and William Finch, who manages the Mines Machine Shop and maker space in the Department of Physics.

Mayotte, who has his undergraduate nad graduate degrees from Mines, said being able to do this work here – and specifically with Mines students being involved – will be integral to the project’s success.

“It is Mines’ combination of great infrastructure, supportive leadership, the fact that we have a highly capable machine shop on campus, and the quality of our students that makes all this possible,” Mayotte said.

Some of the Mines students, both graduate and undergraduate, who have been working on the project include Julia Burton, Tobias Heigbes, Luke Wanner, Nabeeha Mubeen, Auston Froid, Trenton Frederik, Xavier Adams, Nathan Woo, Levi Bar-On and James Brague. Several Mines alumni and staff members have also been key in designing and building the project’s components, Mayotte said.

The potential to observe these high-energy cosmic rays and particles like neutrinos from above will open wide the ability of scientists to gather information, and seeing a neutrino in the atmosphere would unlock bigger mysteries out in space, he said.

“If during flight, we see a neutrino going through the Earth and into the atmosphere, we could correlate it with something out in space, like an exploding star, black hole or neutron star merger, gamma ray burst, those sorts of things,” Mayotte said. “Neutrinos always point directly back to where they came from, which could give us unprecedented knowledge on where these high energy particles are accelerated. It would be a first-of-its-kind observation.

“If we are successful and POEMMA makes it to space we’ll be able to actually figure out where these high energy cosmic rays are coming from, how they’re accelerated and what they’re made out of, which will tell us a lot about the most energetic systems in the universe,” Mayotte said. “We may even access particle physics at energies that we couldn’t possibly get here on Earth.”