Dean Eppler
Geologist
NASA Johnson Space Flight Center

Sage of the Expedition

By Ahmad A. Malik

Dean Eppler strays from the prototypical white-coat scientist tucked away in a corner of a controlled laboratory, conducting meticulous calculations on some inaccessible scientific endeavor. At 62, and within a few months of getting a hip replacement, Eppler fashioned a pair of hiking poles to join a dozen other planetary scientists on a trek through mazes of cooled volcanic flows in one of Earth’s most remote locations.

On the Distance to Mars

In a moment that could have been mistaken for a crime scene, Eppler, in the field, removed an eyepiece from his pocket and interrogated a rock. His colleagues would stand silently at times, hanging on his impending analysis of the sample, waiting to scribble down notes as per his dictation. After gathering his thoughts, Eppler would take a step back, set his gaze upon the outcrop he’d just investigated, and begin to expound a tale of its forensic past. He follows a cold trail of logic, well-practiced over his years of fieldwork.

“The best geologist is the one that sees the most rocks,” said Eppler. “A lot of those kinds of catch phrases are usually wrong, but this one seems to work pretty well. That’s because as you gain experience in the field, you build up this sort of field notebook in your head that sort of says, ‘Oh, I saw that here or there or someplace else, and this is what it meant.’ [That’s] where you go from being a student of random facts to a real geologist. . . Over the course of my 35- to 40-year career, I’ve spent almost two years at various times in the field, living in the backs of pickup trucks and in tents, driving around, looking at rocks and trying to figure out what they mean.”

Eppler enthusiastically flexed his knowledge as a field volcanologist during the 10-day field study in Hawaii for the RIS4E mission, where he served as the crew team leader. His task: to simulate an extravehicular activity, or EVA, that would take place on Mars, and figure out how to best use geological instruments to conduct the best possible science.

No one, it would seem, is more capable of that task than Eppler. After a four-year stint as a U.S Army combat engineer officer in the late 1970s, he earned his Ph.D. in geology from Arizona State University. In 1990, Eppler began working for NASA at the Johnson Space Flight Center in Houston, where he assumed a science management role for the International Space Station. He was also the principal test subject for the development of advanced planetary EVA suits. In effect, Eppler became an expert on spacesuits and extra-vehicular activities.

“I don’t want to say that it makes me uniquely suited to do this,” he said, referring to his role in the RIS4E field campaign. “A lot of other guys could do the same thing, I just seem to be the one who has the most experience.”

With snowy-white hair, a booming voice, and a grab bag of historical allegories that could rival those of a sentimental history professor, Eppler has both a commanding presence and an almost child-like enthusiasm for geology.

As an actual child, Eppler wanted to go to the Moon. Born in 1952, he grew up at the dawning of the space age and the glory years of the Apollo missions, when mankind’s understanding of the Solar System went from dots in a telescope to a grand, close-up tour of the Moon and the eight planets.

Eppler recalled the Mariner missions that were sending back the first images of Venus in the early 1960s. At the time, Venus was known to be completely covered by a thick cloud layer; no one knew what lay below. On a Sunday when he was around nine years old, his father told him that in five days the unmanned spacecraft would have its first fly-by. Eppler thought it would discover dinosaurs.

“I absolutely remember that Thursday came as slowly as Christmas Day comes,” he said. When it came, there were no pictures of dinosaurs, or any other signs of life. “I was much disappointed,” he said. “It was too hot for life.” Half a century later, he sees it differently: “Everything that is known now has come about in my lifetime. The entire world has been stood on its head. And not only in the area of astrogeology. The entire makeup of the field that I am in changed during the time that I grew up.”

Two stories, later in that decade, profoundly influenced Eppler’s burgeoning fascination with space travel—one fictional, the other astonishingly real: The 1968 movie 2001: A Space Odyssey and, later that year, the Apollo 8 mission, the first manned spacecraft to leave the Earth’s orbit and reach the Moon’s.

“When Apollo 8 came along, I said, ‘Oh, this isn’t just movies, man! This is real. I wanted to become a geologist. Apollo made it clear that the Moon was a place to do the geology. ”

Years later, after he began working as a spacesuit tester, Eppler chased his childhood dream of going into space himself. After earning his doctorate in 1984, he applied to NASA’s astronaut program and made it to the interview round three times between 1990 and 1998 before medical issues ultimately disqualified him.

“Most people never get an interview, and to me that was a signal honor,” he said. “It’s still on my resume and whether anybody realizes what it means is immaterial to me.”

Apart from his expertise in spacesuit testing and field geology, Eppler is a student of history. Because of that, he says, “I’ve spent a tremendous amount of time understanding what the Apollo crews did on the Moon. Talking with them, reading the transcripts, reading the histories, getting right down to reading the original memos. . . . So I understand to a certain extent how they did what they did and why—and, when we go to Mars, how we can do what we do.”

Eppler is set to retire from NASA at the end of 2015. But he’s not planning to retire from the field he loves. He’d like to continue participating in field studies, and finally have the time to write—about space exploration through the lens of history.

“My passion is to try and take geology out of the nineteenth century into the twenty-first,” he said. “That’s what I’m going to do for the rest of my life. Even if I’m not working, I’m going to be thinking about that.”

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