APPLIED SPECTROSCOPY
LIAISON BETWEEN ENGINEERING TEAMS AT JPL & SCIENTISTS AROUND THE WORLD
Dr. Vivian Z. Sun
Systems Engineer, Co-Campaign Science Lead
Dr. Vivian Sun is a Systems Engineer and Campaign Science Lead at NASA’s Jet Propulsion Laboratory (JPL).
Curious about space and the planets as a child, Vivian always knew she wanted to work in the field of space science. She studied Planetary Science at the California Institute of Technology where she earned her undergraduate degree, carried out an internship at JPL, analyzing dust devils on Mars, and then moved to Rhode Island where she conducted her PhD research in Planetary Science at Brown University. Her PhD advisor, Ralph Milliken was involved in Curiosity’s science team and therefore she had the opportunity to participate in some daily operations associated with the mission. She also worked with the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM), which uses detectors for visible and infrared light to map hydrated minerals. After completing her PhD, Dr. Sun moved back to California to work as Katie Stack Morgan’s postdoctoral fellow at JPL. She helped interpret data from Curiosity and gained more experience on the operations side, which led to her current role.

PROFILE
DR. VIVIAN SUN
Video Script
Interview with Dr. Vivian Z. Sun, Systems Engineer & Campaign Science Lead
Interviewer: Emily Seo
Emily Seo: You speak about this CRISM instrument that you used during your PhD. Could you explain that instrument and how you measure samples?
Dr. Vivian Sun: Yeah. So the CRISM instrument is on the Mars Reconnaissance Orbiter and it basically, it collects data from I believe half a micron to four microns or so, or possibly out even further. But this is an instrument that collects data at resolutions as low as 18 meters per pixel. And so, I should say actually resolutions as high as 18 meters per pixel because that’s actually fairly good resolution for what we can get on Mars. And so what we’re really able to see with that scale of resolution is we’re able to identify outcrops on the surface of Mars looking at the the orbital images, and then pick out actual mineral compositions.
I’m looking for things like mafic minerals, like olivine, pyroxene and then also hydrated minerals like iron, magnesium, phyllosilicates or clays, carbonates, opal and silica, aluminum phyllosilicates. So, we’re really able to identify a lot of hydrated phases, which of course has a lot of implications for where water might have been in the past on Mars. And so that’s kind of the main features, I think, of the the CRISM instrument.
And, you know, I really enjoyed working with it when I was in graduate school. And, of course, now when I have time I always like to work with it as well. Just because it feels very much like a kind of treasure hunt, right, because we have this cube, this image, this cube of data really because it’s hyperspectral. And then you can poke around the image and find unexpected minerals in certain places. And so I’ve always found it to be a super fun exercise, even though it’s for research.
Emily Seo: Right. So this CRISM is currently working in conjunction still with what’s being done on the Perseverance?
Dr. Vivian Sun: Yeah, so there definitely is intermission coordination, I think just because of the different scales. Perseverance is roving on the surface and collecting data at a much different resolution but CRISM definitely has been useful in helping to plan what we’re doing because since a long time ago the CRISM instrument’s been collecting data from all across Mars. And in particular I think because of the, through the work of a lot of folks in in the field, who have done a lot of studies of Jezero and have advocated for more observations of Jezero with the orbital data sets, including CRISM, we have a fantastic coverage over Jezero Crater. Like the entire area that we’re exploring and that we will be exploring through the delta and marginal deposits, that is all covered by CRISM.
And so CRISM has been incredibly useful for us just to look at the orbital data and say, ‘I think I see like a stronger mineral signature here. Maybe we should focus more on exploring this area as opposed to this other area.’
Emily Seo: Right.
Dr. Vivian Sun: So it’s really been helpful and for guiding where we think we want to go.
HOMETOWN:
Cranbury, New Jersey
FAVORITE SUBJECT(S):
Geology, Planetary Science, Astrophysics
WHAT DID YOU WANT TO BE (when you were young):
Doing something space-related
EDUCATION:
California Institute of Technology, B.Sc. in Planetary Science; Brown University, M.Sc. and Ph.D. in Planetary Science
JOB TITLE:
Scientist, Systems Engineer
INSTITUTE:
Jet Propulsion Laboratory
EXPERTISE:
Remote sensing & Visible-Near-Infrared Spectroscopy of planetary surfaces
ADVICE FOR FUTURE SCIENTISTS:
If you find a topic that is interesting to you, go investigate it, even if work has already been done in that field. You’ll never know what you’ll find, which is what makes research so exciting.
FAVORITE BOOK:
The Little House on the Prairie series (from childhood)
FAVORITE MOVIE:
“Amelie”
FAVORITE FOOD:
Sushi
HOBBY:
Watching NFL football, knitting, cooking, baking
UNKNOWN FACT:
I’m a huge football fan and have a portrait of Tom Brady in my house.
MARS MISSION 2020 ROLE:
Systems Engineer, Campaign Science Lead
WOULD YOU GO TO MARS (if it were possible)?:
If the round-trip travel time wasn’t so long, yes!
MORE IN DEPTH WITH DR. SUN
At JPL, Dr. Sun wears two hats, one as a Systems Engineer on the science operations team and the other as a Campaign Science Lead. As a Systems Engineer, for which she spends the majority of her time, she helps to put together the rover’s daily plans and acts as a liaison between the engineering team at JPL and the science teams which are all over the world. She advocates for the scientists by ensuring their concepts get translated to the engineering plan and that they have the right tools and necessary resources for their studies. As a Co-Campaign Science Lead for Perseverance’s first science campaign on the crater floor, she works to consolidate science objectives, establish campaign priorities, and motivate the team to stay on schedule so that they can maximize productivity.
The unprecedented goal of the Perseverance mission is to bring samples back to Earth, but it is equally important to understand the geological history of Mars. Mastcam-Z is a multi-spectral instrument that gives the big-picture information. “Understanding the context helps you choose the samples to target,” says Dr. Sun. A sample that contains interesting features is further studied using SuperCam. Both Mastcam-Z and SuperCam, referred to as the bread and butter spectral instruments, have remote sensing capabilities and are routinely employed.
When asked what features make a rock or soil sample ideal for further studies by SHERLOC and PIXL, Dr. Sun says, “It depends on the sample.” For example, looking at the crater floor, where the rocks have been altered, the ideal samples would be representative of a major geological unit and prototypical in terms of composition, texture and morphology. In contrast, from the delta, a region believed to potentially have once harbored ancient life, the ideal samples would be materials that have a better chance of preserving biosignatures, like those with high silica and carbonate content.
Many questions are constantly being asked during the Perseverance mission. “Which rock types do we need more data on, and what information do we want our instruments to clarify? Is it the contact between two rocks that we’re interested in? Are these rock samples sedimentary or igneous?” To decide what takes priority, meetings are held with various teams on a daily basis. Despite the hundreds of scientists and engineers involved in the work, they always manage to come to a decision.
To maximize the efficiency of the rover, which includes minimizing travel and sustaining resources, a set time is allocated for each of the major units on Jezero: crater floor, the fan-shaped delta and marginal deposits, which are just outside the delta, lining the sides of the crater wall. The order of exploration for the rover would be from the landing site on the crater floor, moving next to the delta and then making its way to the marginal deposits before exiting Jezero.
Early on in the mission, conglomerates and cross-bedding were observed in the delta, which was expected for this type of environment, but Dr. Sun said it was still amazing to see it from the rover’s point of view since they cannot be viewed from orbital images. They also observed continuous layers in the crater floor rocks which are not visible by orbital means due to the scale and viewing angle. “We didn’t expect to see such extensive layers on the crater floor, which was surprising and exciting.” More recently, scientists have confirmed the presence of igneous rocks on the crater floor. The next step is to figure out the mechanism of their formation and to determine whether they represent a cumulate, lava flow or something else.
Dr. Sun’s biggest challenge is balancing work and life. Because she enjoys her job and her coworkers, she doesn’t mind the challenge. She feels fortunate that the people she works with are kind, intelligent, and always willing to help each other. Despite her limited time, Dr. Sun enjoys many hobbies. She is an avid fan of the NFL and Tom Brady, and not surprisingly, her favorite teams are the New England Patriots and Tampa Bay Buccaneers. She also cooks, bakes and likes to experiment with new recipes, rarely making repeat dishes. To satisfy her fidgeting fingers and to learn new techniques, she knits.
Her advice for early scientists is to follow your interests. Numerous times Dr. Sun had thought that something would be an interesting topic to research, but was reluctant because she’d assume that someone had already done it. She says, “In reality, the planetary science field is so large that you’ll almost always find something new. Take advantage of the opportunity you have as a student to explore what really interests you.” She mentions that an internship in that field is worth pursuing because it gives you a better understanding of what you’re getting into. From her own internship, she learned about her strengths, became familiar with the environment and built long-lasting relationships with her mentors and coworkers, which have all helped her along her career path.
Dr. Sun would travel to Mars if the round-trip was not so time-consuming. One of the first things she would do is pick up a rock and flip it over to see what’s on the other side. To learn more about Dr. Vivian Z. Sun, check out: https://vivianzsun.com/.

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