The Nuclear Science of Asteroid 16 Psyche

Project Overview

In 2011 NASA's MESSENGER spacecraft became the first ever spacecraft to orbit the planet Mercury. That spacecraft carried, among other scientific instruments, a gamma-ray spectrometer built by LLNL. That mission was very successful and data from the spectrometer contributed to a new understanding of Mercury's formation and evolution. LLNL personnel were listed as authors on the hardware papers for that instrument but were not part of the science team and did not participate in the data analysis.

Based on the success of that mission, LLNL is now building three more gamma-ray spectrometers for deep-space planetary missions. These are the spectrometers for a NASA mission to the asteroid belt and one to Titan (Saturn's largest moon), as well as a NASA-funded spectrometer onboard the Japan Aerospace Exploration Agency (JAXA) mission to the moons of Mars. However, the purpose of this LDRD project is to ensure that LLNL not only delivers the hardware but leverages its considerable expertise in nuclear spectroscopy to participate end-to-end in these projects. This includes designing, building, and delivering the hardware, and participating in operations, data analysis and scientific interpretation. This LDRD-ER project funded many activities that established that LLNL has a wide range of expertise to contribute to these projects, including tools to assess and determine optimal probe operations for data collection and data science techniques to analyze observational gamma spectrometer data.

Mission Impact

This project is relevant to the LLNL mission in several ways. First, the past two decades have shown that there is a strong synergy between gamma-ray spectroscopy instruments built terrestrial and national security applications, and those built for planetary science. LLNL has built and commercialized several spectrometers that are now routinely used around the world. These designs benefited from technology developed for space applications (such as the LLNL spectrometer sent to Mercury). Second, nuclear spectroscopy applications in space require knowledge of nuclear physics that is synergistic with LLNL's core nuclear science interests. In particular, these planetary-science applications have discovered shortfalls in nuclear data libraries that are currently being addressed. Finally, involvement with planetary science builds LLNL's skill set and reputation for space-based work in general, and helps with recruiting and funding for LLNL's Space Science and Security Program (SSSP) for projects that are focused on national security.

Publications, Presentations, and Patents

Burks, M. T. et al. 2020. "GeMini: A High-Resolution, Low-Resource, Gamma-Ray Spectrometer for Planetary Science Applications." Space Science Reviews 216, no. 7 (2020): 1-23. https://doi.org/10.1007/s11214-020-00746-y.

Hines, N. 2022. "Designing and Testing the High-Purity Germanium Gamma-Ray Spectrometer for the Dragonfly Mission to Titan." Ph.D. Dissertation 2022. https://www.osti.govf/servlets/purl/1890788.