Planetary Sciences Tribute

Claudia Joan Alexander (1959–2015)

Alexander is remembered for her leading role in the Galileo and Rosetta missions and her efforts to encourage women scientists from underprivileged and underrepresented groups.


Claudia Alexander. Credit: Courtesy of NASA/JPL-Caltech
Claudia Alexander. Credit: Courtesy of NASA/JPL-Caltech

Claudia Alexander, who oversaw the dramatic conclusion of the Galileo mission to Jupiter and was the NASA project scientist for the international comet-chasing Rosetta project, died of breast cancer on 11 July 2015. She was 56.

Claudia was born in Vancouver, British Columbia, Canada, on 30 May 1959. The family moved to Northern California when she was 1 year old, and she grew up in Santa Clara. Her father, Harold Alexander, was a social worker, and her mother, Gaynelle, was a corporate librarian for chipmaker Intel.

Early Life as a Space Science Student

Claudia wanted to study journalism at the University of California, Berkeley (UC Berkeley), but her parents “would only agree to pay for it if I majored in something ‘useful,’ like engineering,” she once said in an interview. During college, she became an engineering intern at NASA’s Ames Research Center. She found herself drawn to the space facility and visited it as often as she could. Her supervisor eventually arranged for her to intern in the space science division. She went on to earn a bachelor’s degree in geophysics at UC Berkeley in 1983 and a master’s in geophysics and space physics at UC Los Angeles in 1985. After earning her master’s degree, she joined NASA’s Jet Propulsion Laboratory (JPL) as an instrument representative for the Near Infrared Mapping Spectrometer of the Galileo mission.

In 1988, she enrolled in the doctoral program in space and planetary physics at the University of Michigan, Ann Arbor, where she worked on thermophysical modeling of cometary nuclei under my guidance. In 1993, she defended her Ph.D. thesis and returned to JPL, where she continued her research on comets and the early history of the solar system.

Role Model for Young Women Scientists

At Michigan, she was also very active in student life. She was lighthearted, an instigator of many jokes, and had great success imitating my heavy Hungarian accent. In her more serious moments, she initiated high-impact outreach efforts to underprivileged and underrepresented groups. She worked extensively with inner city students in Detroit and helped many young women to finish school. Some were motivated enough by Claudia to attend institutions of higher learning. She was particularly enthusiastic about working with young women of color and becoming a role model for the next generation.

Her efforts were recognized and appreciated at Michigan. In 1992, she was named University of Michigan Woman of the Year in Human Relations. She continued to have a strong relationship with the university over the years, and in 2002, she earned the Department of Atmospheric, Oceanic and Space Sciences (AOSS) Alumni Merit Award. She also served on the AOSS National Advisory Board. In 2007, her uncle, Jiles Williams, established the Claudia Alexander Scholarship for undergraduate students at Michigan.

Leading the Galileo and Rosetta Missions

During her 3 decades at NASA JPL, she served as the last project manager of Galileo, one of the most successful missions for exploring the distant reaches of the solar system. Claudia was leading the mission when scientists orchestrated its death dive into Jupiter’s dense atmosphere in 2003, when the spacecraft finally ran out of fuel after 8 years orbiting the giant planet. Her leadership resulted in major new discoveries about the upper layers of Jupiter’s atmosphere, including its composition and dynamics.

Beginning in 1998, she was Rosetta’s U.S. project scientist, and for an extended period of time, she also served as project manager, coordinating with the European Space Agency on the orbiter’s journey to rendezvous with the 67P/Churyumov-Gerasimenko comet as it circled the Sun. She played a critical role in integrating the disparate science team into a coherent science enterprise, and she led the effort to relate Rosetta’s observations to our understanding of the formation of our solar system.

In her spare time, Claudia wrote two books on science for children and mentored young people, especially African American girls. On the U.S. Rosetta mission’s webpage, she wrote, “Throughout school I was one of few women in class and didn’t feel very feminine talking my way through engineering applications like dam or bridge building. At that time there were few female role models to give me a vision of myself as a professional engineer. I wasn’t feeling very validated, which played hugely into my self-esteem at the time. But I stuck with it. When I was a senior in undergraduate school, a professor nudged me into a senior project on Earth’s carbon cycle. It turned out great. He was really pleased and pretty much got me into graduate school. It was a case of a professor believing in me. Fifteen years later, I was chosen to be the project scientist on Rosetta, a lifelong dream, and my life has never been the same!”

We mourn the loss of Dr. Claudia Alexander, a dedicated scientist, inspiring role model, and one of the nicest people I ever had the pleasure of working with.

—Tamas I. Gombosi, University of Michigan, Ann Arbor; email: [email protected]

Citation: Gombosi, Tamas I. (2016), Claudia Joan Alexander (1959–2015), Eos, 97, doi:10.1o29/2016EO043367. Published on 12 January 2016.

© 2016. The authors. CC BY-NC 3.0