Stellar Student

Undergraduate research: Charity Woodrum rides a NASA internship to the forefront of astrophysics
Charity Woodrum

It’s an understatement to say that, for Charity Woodrum, it was exciting to intern at NASA. Simply put, she was overwhelmed.

“The first week I was holding back tears,” the UO physics major said. “You’re constantly reminded that you’re working with people who have made some of the biggest discoveries in the history of humanity. You think about it on a daily basis.”

This summer, Woodrum enjoyed the kind of wide-eyed adventure that most undergraduate astrophysicists-in-training could only dream about: 10 weeks as an intern at NASA’s Marshall Space Flight Center in Huntsville, Alabama, where she worked with leading scientists to advance understanding of cosmic phenomena that have only recently come to light.

This wasn’t your run-of-the-mill internship built on coffee runs and busy work. Following in the steps of a Duck who landed the same prestigious opportunity a year ago, Woodrum was expected to make significant contributions to evolving research.

For a talented and passionate emerging scientist who came to astrophysics following a career change, the revelation was exhilarating—and perhaps just a bit unsettling.

“They’re not just making up random jobs for interns to get experience,” Woodrum said, halfway through her internship. “We’re doing things that are really important for their missions.”

Fermi telescope

Woodrum, on the hunt for gravitational waves, reviewed images collected by the Fermi telescope (above) and stored as data. She ran calculations that sifted through this information, in a search for previously undetected events. She didn’t find any, which validated NASA’s methods.

Under Fermi’s watchful eye, Woodrum worked on a topic that has been called one of the biggest breakthroughs in physics in 100 years: the existence of gravitational waves.

The theory, predicted by Albert Einstein a century ago, postulated that energy ripples move across the cosmos, causing space and time to expand and contract. The waves were detected for the first time last year, with UO physicists playing a key role in verifying them; the proof of gravitational waves validated a fundamental tenet of Einstein’s theory of relativity and triggered speculation that a Nobel Prize is on the way to the lead research team.

Now the hunt is on to see just how many gravitational waves can be found.

The observatories in Washington and Louisiana that detected the first gravitational waves weren’t designed to capture all of them or pinpoint their origin. It’s possible that smaller waves are zipping past the facilities unnoticed.

But they’re not going to escape the attention of NASA’s Fermi Gamma-Ray Space Telescope, which is in a low orbit around the Earth. The telescope can pick up the gamma rays that are emitted when an explosive event—say, the collision of a black hole and a star—triggers the release of gravitational waves.

Last summer, scientists at the Marshall Space Flight Center made it their top priority to ensure that the telescope is capturing anything that could be a short gamma ray burst, the telltale companion to a gravitational wave. It was Woodrum’s job, essentially, to check the telescope’s work.

The telescope picks up gamma rays using cylindrical sensors that cover about 70 percent of the sky and run almost constantly. Gamma rays from the deepest reaches of space bombard it nonstop.

The frequency and strength of those rays are converted into data that is run through complex calculations to sift out other disturbances. The result is a collection of only the strongest readings—blasts that are most likely the footprint of a high-energy event that could produce gravitational waves.

NASA scientists wanted to comb through the data at an even finer level to determine if the telescope was picking up gamma ray bursts that hadn’t been previously revealed in the computer readings. Woodrum was assigned to rewrite parts of the programming to make that happen.

“My goal was to find as many short gamma ray bursts as possible,” she said.

Not a millisecond to spare

Working with a month’s worth of information from the telescope, Woodrum adjusted computer calculations to bring into view additional data. NASA had been analyzing footage from the telescope at 25-millisecond intervals—Woodrum made this even more precise, dialing in intervals of four and 16 milliseconds.

gamma sky map

The Fermi Gamma-ray Space Telescope gave Woodrum new “eyes” into space. This image is a map of the sky at gamma-ray wavelengths, accumulated over six years of operation by the telescope.

Nothing new showed up—no additional so-called “candidates” were hiding in the data. Woodrum’s conclusion: Fermi wasn’t missing any gamma-ray events, and therefore, no additional gravitational waves had snuck past.

“I presented (my research) to them, and they decided that it was not useful to go down to the shorter times,” she said. “The 25-millisecond intervals were perfect, which made them happy.”

Imagine being an undergraduate and an intern, and making an astrophysics presentation to a room full of the brightest minds in the country. For Woodrum, that was a reality.

“You have 11 NASA scientists staring at you, and they are all experts in their field and you’ve only been there for a month,” she said. “It’s intimidating and challenging, but it’s really fun, too, and rewarding. It’s a really steep learning curve.”

How important was Woodrum’s research to the Fermi telescope project? When she arrived for the start of her internship, she was shown a checklist of 13 to-do items that NASA scientists had compiled. After her investigation, they crossed an item off the list—analysis of “finer” data for evidence of gravitational waves.

NASA scientists also planned to pull from Woodrum’s work when they write a review of the project.

Michelle Hui, a research astrophysicist at Marshall who was Woodrum’s mentor, said the intern’s computer programming skills made her perfect for the assignment she was given.

Hui was so impressed with Woodrum’s dedication and energy that she discussed working with her as a liaison between NASA and the UO research group that helped detect the gravitational waves.

Over 10 weeks at Marshall, she watched Woodrum grow into an independent thinker and valuable contributor.

Said Hui, “She takes things into her own hands.”

Woodrum is the second UO student in two years to land an internship at NASA Marshall through an Oregon consortium that promotes education in the sciences. Fellow physics major Manju Bangalore interned at the space flight center in 2015, working with the technology development division to find the best propulsion method for space travel.

Scott Fisher, director of undergraduate studies in the physics department, said Bangalore and Woodrum both went into their internships equipped with the knowledge and skills that they needed to succeed—and frequently were ahead of their peers in that regard.

“To me, this is a strong validation of the preparation that UO and UO physics instills in our students,” Fisher said. (For more on the research opportunities available to physics undergraduates, see Cosmic Connections.)

Butterflies and Stephen Hawking

The Marshall Space Flight Center is the US government’s rocketry and spacecraft propulsion research center.

As the largest NASA center, Marshall was first tasked with development of the Saturn launch vehicles for the Apollo moon program in the 1960s and 1970s. Marshall is the agency’s lead center for Space Shuttle propulsion, related crew training and International Space Station design and assembly.

In tours and presentations, Woodrum and the other interns saw it all, from a mock-up of the International Space Station to the prototype of the ship being designed to take the first humans to Mars. Even better, they heard about these projects from the scientists running them.

“You get chills and butterflies,” Woodrum said, “as you are walking around hearing what everybody does for their work.”

For her, astrophysics begins with Stephen Hawking.

Woodrum was a community health nurse in southern Oregon’s Douglas County, and the emotional strain of an otherwise satisfying job was beginning to take its toll. So to clear her head, she read whatever she could find by the famed theoretical physicist.

It wasn’t exactly light reading, but Woodrum devoured it. What she thought was a distraction was actually a passion, she discovered—she wanted to become an astrophysicist.

“Because life experiences are determined by what perspective you have, I thought, ‘What’s the most interesting perspective I can have in my life?’” Woodrum said. “I decided I wanted to experience life through the eyes of an astrophysicist.”

The learning curve for astrophysics is steep. On the first day of class, students are learning Newton’s laws—and by graduation, they’re tackling quantum mechanics. Think of it as 300 years of human discovery squeezed into the four years it takes to earn a physics degree, Woodrum said.

Even so, she has distinguished herself in this reinvention as a college undergraduate, not just with her course work but with her contributions to the department’s research (see below).

Woodrum is on her way to a new career that will be focused on gazing at the stars. Her experience at NASA was—dare we say it?—one small step closer.

“I’m a bolder scientist and learner now,” Woodrum said. “One of the skills I’ve brought back is to not be afraid to try something that’s really hard that you’ve never done before.”

As part of her tour of Marshall Space Flight Center, Charity Woodrum visited a mock-up of the International Space Station, which also serves as a lab. Just like in the movies, when work needs to be done on the actual space station, engineers first head to the mock-up to do dry runs.

—By Jim Murez

Satellite photo credit: NASA/Goddard Space Flight Center Conceptual Image Lab

Gamma Ray Map photo credit: NASA/Fermi/Sonoma State University/A. Simonnet