Micro-Sampling System for Mineralogical Instruments

The CheMin X-ray diffraction (XRD) instrument, successfully deployed on Mars Science Laboratory (MSL) for more than 7 years, established the quantitative mineralogy of the Mars soil, characterized the first habitable environment on another planet, revealed in-situ evidence of Martian silicic volcanism, documented the dessication and oxidation of the environment in Gale Crater during Hesperian time, established an upper limit for CO2 in the early Mars atmosphere, and provided ground truth for orbital measurements. CheMin as-designed is restricted to Flagship-class missions due to its size, mass and power, as well as its reliance on a heavy and mechanically complex sample collection system. Deployment of XRD on smaller rovers (MER type) requires instrument miniaturization and a light weight sampling system. We propose a Micro-Sampling System for in-situ analysis of rocks and soils, focusing on weight-saving solutions for smaller landers and rovers. This research will cover all aspects of sample management from powdered sample collection to XRD analysis, exclusive of the transport assumed to be provided by a robotic arm. We will focus this research on XRD analysis, but other analytical techniques could benefit from this sampling system, individually or as part of a suite of instruments analyzing the same sample. The Micro-Sampling System will be divided into two major subsystems: a Powder Collection and Delivery (PCD) system fitted to a rover/lander arm, and an Instrument Sample Manipulator (ISM) internal to the XRD unit. The PCD will be designed for low power and load requirement, precise sampling, and preservation of mineral species. Methods for the collection of powder from rocks will be the subject of an initial trade study leading to a PCD breadboard development. This engineering effort will be conducted by Honeybee Robotics. The ISM will rely on one-time use sample cells loaded on a single tuning fork design utilizing the same vibrated cell method used in CheMin. A new cell will be pushed in place prior to each analysis, with new pristine cells stored in a cartridge. Mechanism studies and breadboard development will done by Honeybee Robotics engineering staff under the lead of the PI. A field-deployable XRD instrument will be built by the PI around the ISM breadboard to allow its evaluation in a complete analytical system, and verification of XRD performance. Extensive tests will be conducted by CoI Lafuente with this instrument. Higher fidelity prototypes of the PCD and the ISM will be developed by Honeybee Robotics and tested jointly in their Mars chamber, under critical conditions of vacuum and heavy dust contamination. By the end of this 3-year effort, we will demonstrate a full “rock to data” system and make it available for field campaigns. This PICASSO addresses critical improvements in technology for the deployment of next generation XRD instruments for definitive mineralogical analysis. This work targets Discovery class missions and MER size rovers in particular. The sampling system and associated XRD instrument will enable the determination of quantitative mineralogy from rocks and soils on Mars, the Moon, or other rocky planetary bodies. The combined expertise in Mars rover operation of CoIs Yen (MER and MSL), Bristow (MSL) and Blake (MSL) will be leveraged through this research to provide technologies that answer real operational needs of remote planetary science. This work leverages 20+ years of development of advanced XRD systems for planetary and commercial applications by the PI and his collaborators, a number of SBIR, MIDP, PIDP, ASTID, PICASSO, MatISSE and DALI grants for the development of planetary X-ray instruments and associated sample handling, and the expertise of Honeybee Robotics in planetary sample handling. More »