The Future of Laser-Based Technologies in Space Exploration: An Interview with Kelsey Williams, Part IV

National Space Day is being celebrated by promoting and advancing space exploration research. Spectroscopy is commemorating this day by publishing content that highlights the contributions being made in this field. In this extended Q&A interview, we sit down with Kelsey Williams, a postdoctoral researcher at Los Alamos National Laboratory (LANL), who is working on planetary instrumentation using spectroscopic techniques such as laser-induced breakdown spectroscopy (LIBS) and laser ablation molecular isotopic spectrometry (LAMIS) (1–3).

Kelsey Williams is a postdoctoral researcher at Los Alamos National Laboratory (LANL). Photo Credit: © Kelsey Williams.

In Part III, Williams goes into detail about ChemCam and SuperCam and how LIBS is used in both of these instruments. In the final part of our conversation with Williams, she discusses how laser-based spectroscopic techniques might be used in the future to advance space exploration.

LIBS has been successfully used on Mars rovers. Given LANL's expertise in laser spectroscopy, what are some of the future directions or potential advancements in LIBS or other laser-based spectroscopic techniques that you see as particularly promising for future space exploration missions to other celestial bodies?

A lot of what we do here is planetary-based, at least what I do is planetary-based. However, there's plenty of other research happening here at LANL involving space exploration. I have a bias because I think that LAMIS shows great potential in getting isotope distributions from a geologic sample. After all, it tells you a lot about it. It tells you where it comes from. It can tell you how old it is. It can tell you how it got there. It could tell you what happened to the land in that area. And so, I think that's something that I'm excited about advancing to get it to the next level, where it is something that we do put on a planetary body.

In addition to LAMIS, a lot of technologies that we use on Earth are being advanced. There are lasers that are coming out that are lower-power consumption, but they still can put out relatively high energies compared to the lasers that are currently used on these planetary missions. And so, one thing that I'm looking forward to is how are we going to exploit the lasers?

Another thing is detector technology. The current state of the art in the laboratory for LIBS is the intensified charge-coupled device (ICCD), which is basically like a camera in your phone, and then we put a phosphor in front of it to improve the signal and are able to collect spectra at different time delays. Detectors are being developed that might even afford us the capability to perform Raman, LIBS, luminescence, and LAMIS experiments all at one point off one laser shot. The technology isn't quite there yet, but it's on a path to get there. Something that I'm passionate about is looking at the technologies that are currently being developed for other things and understanding how we can take that and implement it into these planetary instruments. So, yeah, I think right now, though, if we're looking into the more immediate future, I think LIBS on the Moon is something that's a goal that we have.

How is LANL leveraging or developing advanced spectroscopic techniques, such as Raman spectroscopy or infrared spectroscopy, for future missions focused on these more complex analyses in the search for life beyond Earth?

The overarching project that I'm on is a planetary project that is interdisciplinary and focused on tackling that kind of a question of what we need to understand to make these types of detections. And so, as I mentioned previously, Raman and infrared are part of the SuperCam instrument.

Part of all of this is that we need to better understand how the fundamentals of these techniques work in the environment that they're currently in, right? Because doing things on Earth is a lot different than doing them on Mars or doing them on the Moon. And so, to best be able to understand the information that we're getting out of a Raman signal, we need to do the studies of the fundamentals. Along with that, we have to be able to understand if a certain type of biological species is present, and what the detection is going to look like. Part of the project I'm working on, there is a group of people that are investigating the detection of biological material. So they're growing, exposing, and analyzing bacteria under various environmental conditions, including irradiated conditions, so we can get an idea of what types of signals we should expect.

Astrobiology is not my expertise, but there's a dedicated team working to understand that goal. Another thing that's way out of my expertise is machine learning. We work with a machine learning team that is taking Raman, LIBS, luminescence, whatever data they can from what is currently available, and developing techniques that can be used to better quantify and identify what is on the Martian surface. For instance, the idea is that we would be able to take a spectrum acquired from one of these rovers and enter it into this kind of system, and it will be able to quantify all of the different elements that are in there, and possibly, in the future, provide some sort of mineralogical information. And then, along with all of that, we must package that into an instrument that can make those measurements to a level that the information is useful, right? So, you can have an instrument that measures elemental composition, but if it can only detect 50% or higher, is that useful for what we're doing? And the answer is no. So, we must figure out how to make these into a nice, small package and be able to maximize the information we get out of them. What I (and we all) do can't be limited to one thing, because it's kind of this iterative process where some of us will work on some fundamentals and go back to the instrumentation and talk to the data science team, and then come back to the astrobiology team and ask what they're looking for, and what are the detection limits that we need to start aiming for. It's this flowing circle of information and ideas and development, and reworking. There are a lot of things currently happening right now that we're doing, and I'm excited to be a part of it.

References

1. Wetzel, W. The Impact of LIBS on Space Exploration: Mars. Spectroscopy. Available at: https://www.spectroscopyonline.com/view/the-impact-of-libs-on-space-exploration-mars (accessed 2025-04-23).
2. McMillan, N. Laser-Induced Breakdown Spectroscopy (LIBS). Carleton.edu. Available at: https://serc.carleton.edu/msu_nanotech/methods/libs.html (accessed 2025-04-23).
3. Wetzel, W. Celebrate National Space Day with Spectroscopy. Spectroscopy. Available at: https://www.spectroscopyonline.com/view/celebrate-national-space-day-with-spectroscopy (accessed 2025-04-23).