Maturation of the Potassium-Argon Laser Experiment (KArLE) (KArLE)

Maturation of KArLE (Potassium-Argon Laser Experiment) for in situ planetary geochronology Barbara A. Cohen, NASA MSFC 1) Description of the science goals and objectives to be addressed by the proposal: The proposed Potassium (K) - Argon (Ar) Laser Experiment (KArLE) is intended to provide the capability for in situ dating in planetary missions. KArLE will simultaneously measure K and Ar on a given sample to achieve a precise age, while also performing additional analyses of common interest such as elemental analysis and imaging on rocks of interest to lander and rover missions. Previous development work under a PIDDP grant has proved the KArLE concept in a laboratory environment, both at the component level and through end-to-end tests, to achieve TRL 4. We seek to mature the KArLE architecture to TRL 6, suitable for proposing to future flight missions. 2) Brief description of the methodology to be used to address the science goals and objectives: The KArLE-unique hardware consists of a small vacuum chamber, a focusing lens set, partner instrument interfaces, and a sample handling system. The stationary KArLE hardware is intended to interface with flight-heritage instruments: a Laser-Induced Breakdown Spectroscopy (LIBS), mass spectrometry (MS), optical imaging instruments, and lander/rover drill or sample handling system. The KArLE design to interface with existing, flight-proven instruments offers a low cost, low risk approach to accomplish additional and highly-desirable science measurements with minimal extra hardware. In this proposal, we will mature both the KArLE hardware and techniques. We will build engineering prototypes of a KArLE chamber and lens set, sample-introduction hardware and a resealable vacuum flange that will mate to the KArLE chamber, and a small mass-range quadrupole mass spectrometer. We will integrate these into a brassboard along with LIBS and camera optical interfaces. The brassboard KArLE suite will be subjected to environmental (thermal vac, vibration) testing and end-to-end sample analysis on appropriate lunar analog and meteorite samples. 3) Relevance of the proposed research to this call: Absolute ages are the backbone of understanding lunar thermal and impact history, and by extension, the historical framework for the solar system. A geochronology capability will be crucial for investigating lunar formation, bombardment, and magmatic history, because we cannot possibly bring back samples from everywhere on the Moon. In situ geochronology has been proposed for inclusion in Discovery missions in the 2014 call and will be again to the 2019 call, but thus far has not advanced to TRL 6. For a first-time use of in situ geochronology, it is critical to advance the maturity of the approach before a mission risks including it. We mature the KArLE concept for Discovery, but will also develop envelopes to understand how commercial lander capabilities would be able to carry all or parts of KArLE. This project will mature both components of the KArLE system and the overall KArLE architecture to TRL 6. More »