Voyager Scientist Celebrates 50 Years at Caltech

Five bird-watchers paused on Wilson Avenue, binoculars trained on a bright yellow goldfinch. The group's leader, a man with a twirled mustache and NASA baseball cap, earnestly marked the find on his checklist.

Alan Cummings (PhD '73), senior research scientist in the Space Radiation Laboratory at Caltech, has been observing Caltech's birds for 37 years. But he's been working at Caltech even longer than that, developing experiments, analyzing data, and managing projects for various space missions, including NASA's Voyager program. This month, he was recognized for 50 years of service to the Institute.

Cummings first came to Caltech as a graduate student in 1967 and earned his PhD in physics in 1973. Then, a fiasco with his graduate thesis experiment led to the opportunity of a lifetime.

"There was an active balloon program going, where every summer you took your experiment up to Fort Churchill, Canada [Churchill Rocket Research Range], and you tied it onto the bottom of a huge balloon that goes to the top of the atmosphere and measures cosmic rays of various kinds," says Cummings.

His research, which focused on cosmic ray positrons and electrons, required several trips and balloon deployments. But that summer, his balloon went off track.

"Well, the command to bring the balloon down in an area not far from Fort Churchill was sent and it didn't work. And then they had a backup timer on board that would make it come down. That didn't work either."

The massive balloon drifted over Russia and was grounded by the USSR. Cummings was able to go pick up the broken remains of his project and bring them back to Caltech. But the damage was too great to resurrect the experiment.

"That whole thing about the balloon failing was fortunate in a way," reflects Cummings, "because then I was offered a position working on Voyager."

Just after earning his PhD, Cummings was hired as a research scientist in the Space Radiation Lab. The Voyager mission was in its early stages at the Jet Propulsion Laboratory (JPL), which Caltech manages for NASA. Cummings began working closely with principal investigator Rochus E. "Robbie" Vogt and Voyager project scientist Edward Stone to help develop the Voyager's Cosmic Ray Subsystem (CRS) experiment.

The mission included twin spacecraft, Voyager 1 and 2, which launched in 1977 for a "grand tour" of the solar system. What was originally intended as a five-year exploration of Jupiter, Saturn, and their moons became a 46-years-and-counting mission that has studied Jupiter, Saturn, Uranus, Neptune, 48 moons, and is currently taking measurements in interstellar space.

The CRS, one of five still-operating scientific instruments on the spacecraft, includes three types of telescopes that detect energetic particles called cosmic rays. The CRS studies the composition, direction, and energy spectra of various populations of cosmic rays, including galactic cosmic rays, which are thought to result from supernovae explosions. These measurements provide keys to understanding the nature of our sun, solar system, its boundaries, and the interstellar space beyond.

Cummings has remained loyal to the mission for 50 years now: "Since it was launched, I've worked fairly continuously on data analysis for Voyager, as well as helping develop instruments for other space missions." From his earliest work helping fabricate and test the CRS equipment—his claim to fame is that he was the last person to touch both spacecraft while inspecting the CRS before launch—to his ongoing analysis of cosmic ray data, Cummings says the Voyager mission has been his favorite part of working at Caltech.

Cummings says he hopes to stick around until the CRS instrument is turned off, which may happen in a few years. "It's been great, to be able to have one mission last this long and coincide exactly with my career."

Cummings has presented three lectures for JPL's prestigious Theodore von Kármán Lecture Series: one in 2007 for the 30-year anniversary of Voyager's launch, one in 2012 just before Voyager 1 entered interstellar space, and one in 2017 for Voyager's 40-year anniversary. In the lectures, he describes his research, cracks jokes, and highlights memorable experiences from the mission, including seeing Jupiter's volcanic moon Io for the first time and Voyager 1 becoming the first human-made object to reach interstellar space.

Beyond breakthroughs with Voyager, Cummings has one more favorite memory at Caltech: meeting his wife.

"I was taking my thesis over to get it printed at Keith Spalding, the business-services building, and Suzette was going down while I was coming up," says Cummings. It was his final year as a graduate student, and a mutual acquaintance had suggested to Alan that he ask Suzette, who worked in the ticket office at Caltech, out on a date. But he hadn't mustered up the courage to introduce himself before then.

"I decided to wait around in the lobby until she came back up, and then we met—it was on her birthday," says Cummings. "Our first date was six days later, on my birthday. It was kind of a fairy-tale deal." The two dated for several months and got married the same year, 1973.

Both continued as staff at Caltech, with Suzette subsequently working in the president's office, provost's office, dean's office, and ultimately as assistant to the vice president for student affairs. She was recognized as an honorary alumna in 2001 and retired in 2012, after more than 40 years of service. "My wife's much more famous around here than I am," Cummings adds.

Nonetheless, Cummings has a legacy of his own on campus as one of the founders of Caltech's bird-watching group, which has been going on "bird walks" every week since 1986.

"We've done over 1,700 walks now," says Cummings. On Tuesdays around noon, the group convenes to trek across campus and look for birds. Group members have come and gone, but Cummings is always there. He diligently tracks each walk's data, noting walk attendees and how many birds and which species the group spots.

On May 23, five bird-watchers embarked on their usual route under overcast skies, bantering and pausing to observe acorn woodpeckers and red-whiskered bulbuls. Cummings led at the vanguard, attentive and with checklist poised.

"Each walk is about two miles, so it's not for everybody. I mean, I can quite understand when people come and then they leave after a few walks," says Cummings.

"But once you have this inertia going, it's hard to stop. You know, you've got a huge amount of data that you've collected, and you just feel obligated to keep it going. It's almost like Voyager."