Pressing Charges: USU Physics Doctoral Scholar Awarded Prestigious NASA Research Fellowship

Space is a precarious environment of high vacuum — that is, extremely low pressure — along with extreme temperatures and blasts of varying radiation exposure. Creating spacecraft that can withstand drastic temperature variations ranging from hundreds of degrees below freezing to blistering heat, coupled with ultraviolet radiation, ionizing radiation and cosmic rays, is a formidable challenge.

Within this environment, spacecraft accumulate electrical charges that can destroy costly, critical equipment, endanger astronauts and abruptly end a mission. Case in point: The famed Apollo 13 mission narrowly escaped disaster when extreme heating due to an electrical arc in an oxygen tank ignited the Teflon insulation and caused an explosion.

“It’s a delicate balancing act to determine the right materials for building a satellite or spacecraft that will transport humans,” says Utah State University physicist Tyler Heggenes. “NASA is intensely concerned about charging because some equipment on spacecraft are going to be really strong insulators, so the charge will enter them and wlll stay, essentially, completely still.”

In that situation, Heggenes says, if a charge builds up that is too big for an insulator to hold, a discharge arc, which is a strong electrical current, can occur.

“An electrical current like this could fry computer chips or worse — it could be really bad news,” he says, citing NASA’s Galaxy 15 telecommunications satellite that was set adrift from orbit in April 2010, following a suspected arc.

With physics faculty mentor J.R. Dennison, Heggenes is refining ways to measure conductivity in varied insulating materials in response to punishing and unpredictable radiation exposure, with the goal of developing a model for maintaining electrostatic equilibrium within those materials.

The doctoral scholar was awarded a 2025 NASA Science and Technology Graduate Research Fellowship to pursue continued study. The competitive, four-year fellowship pairs Heggenes with a NASA mentor, who will arrange for the USU student to visit varied NASA labs and conduct research with NASA professionals. In addition, the fellowship provides about $80,000 in funding each year, includng a $40,000 stipend, along with full tuition, health insurance and an allowance for operating expenses and travel to professional conferences.

“This is one of NASA’s premier fellowships, which are designed to provide a pathway for students to pursue research career opportuinities within the agency,” says Dennison, professor in USU’s Department of Physics, who has mentored previous fellowship recipients. “That NASA has kept this fellowship going despite federal budget cuts is a testament to the agency’s commitment to this student program.”

A native of Washington state’s rural Whidbey Island, Heggenes says he’s always been fascinated by space and science, and initially planned to pursue a career as an orthopedic surgeon.

“I volunteered in hospitals across multiple states, spent hundreds of hours shadowing physicians and earned emergency medical technician certifications,” says the 2023 graduate of California’s Concordia University Irvine. “My medical goals were within grasp before I was led to a revelation by one of the surgeons I shadowed: All my leisure time within an educational context was strictly related to space and physics.”

The epiphany led Heggenes to rethink his career path.

“I realized I wanted and needed more than just research for the sake of learning, but also to help expand humanity’s reach in space,” he says.

Heggenes learned of Dennison’s Materials Physics Group and its research of space environment effects and spacecraft charging. He applied to USU and, on his initial visit to the Logan campus, spent more than two hours talking with Dennison.

“Working with Dr. Dennison’s group has opened many doors for me, including NASA-funded projects,” he says. “This includes the important, and often over-looked, topic of radiation-induced conductivity, also known as ‘RIC.’”

Heggenes notes John Fowler (1925-2016), a pioneer in RIC research, followed an academic path that was a mirror image of his own.

“As a physicist, Fowler conducted seminal research on the effects of radiation on conductivity, but left physics to pursue a medical degree and dedicate the rest of his career to the field of medical radiation,” he says. “Fowler demonstrated the interconnection of RIC to a deeper understanding of physical phenomena as a whole and how this concept is relevant to space technology.”

Heggenes says he doesn’t want to exaggerate the potential influence of his proposed studies on RIC research, but he points out most spacecraft anomalies result from spacecraft charging issues.

“I’m inspired by Fowler’s example and how he was open to pivoting to a new field,” he says. “I’m grateful for my winding route through medicine, carpentry, EMT work, construction jobs and sports, which has broadened my perspectives and experiences.”

Heggenes says he envisions developing methods to provide low-noise, fast time-interval data of RIC with time-dependent “fits” — that is, adjustable equations — to noticeably supplement spacecraft charging models.

“It’s a meaningful contribution I can make to help fellow humans safely and effectively explore the universe,” he says.