Preparing for Artemis with ANGSA: The Dissection and Characterization of Previously Unopened and Sealed Double Drive Tube 73001/2

The Apollo Program returned 382 kg of samples. Analyses of Apollo samples have provided fundamental insights into the origin and history of the Earth-Moon system, and they have been used to place important constraints on the origin and evolution of other planets, and even our Solar system itself. After 50 years of curation, analysis, and study, our sophistication for handling and examining samples has greatly increased due to advancements in technology as well as the ability to build on previously attained knowledge [1]. Some Apollo samples were collected or preserved in unique containers or environments and have remained unexamined by standard or advanced analytical approaches. The Apollo Next Generation Sample Analysis (ANGSA) initiative, with 9 selected teams [2], was designed to examine a subset of these special samples and to function as a “new” sample return mission with processing, preliminary examination (PE), and analyses utilizing new and improved technologies and recent mission observations [e.g., 3-6]. The ANGSA initiative links the first generation of lunar explorers (Apollo) with future lunar explorers (Artemis) [2]. Klaus Keil was a pioneer in petrology and mineralogy who dedicated his life to the study of extraterrestrial samples, including lunar samples. To honor Klaus’s lifelong devotion, in this abstract we will examine the characterization of unopened and sealed double drive tube 73001 and 73002 with the focus on processing the core including the petrological and mineralogical characterization of clast lithologies. Apollo sample 73001/2 is a ∼71cm long double drive tube consisting of an upper part (73002) and a lower part (73001) that contains regolith collected near Lara Crater at the Apollo 17 site, Station 3. The double drive tube is postulated to have penetrated a lunar landslide deposit that was transported from the slope of the South Massif into the Taurus-Littrow Valley [7]. As part of the ANGSA initiative, preparing a preliminary examination (PE) catalog of 73001/2 is a crucial first step for the early identification of material types such as rock fragments and potential stratigraphy within the core. Many new curation and scientific tools such as X-ray computed tomography (XCT) [3], multi-spectral imaging [4], and gas extraction manifold with piercing tool [5-7], have been applied to the ANGSA core to benefit curation strategy, PE efforts, sample allocation to the planetary science community, and ultimately help to prepare for future sample return missions like Artemis. Sample 73002 was successfully opened and extruded in Nov. 2019 (Fig. 1a) and fully dissected at the end of 2021. Sample 73001 was successfully extruded in March 2022 and fully dissected at the end of June 2022 after careful planning to pierce and extract gas from the vacuum sealed Core Sample Vacuum Container that was holding drive tube 73001. Processing the core after opening and extruding happened in several stages: 1) The core was dissected in three passes: top part, middle part, lower part (Fig. 1c). Each pass was then subdivided into 0.5mm wide intervals with about ∼1cm height. The leftover core (after the 3rd pass was dissected) was impregnated with epoxy and turned into continuous thin sections along the length of the core. Larger rock fragments (>4 mm particles) were separated from the regolith and scanned at high resolution by XCT for initial characterization. 349 individual fragments were separated, scanned, and classified into one of the following lithologic categories: agglutinates, basalts, impact melts, impact melt breccias, regolith breccias, soil breccias, and unusual clasts (Fig. 2) [8]. BSE and X-ray mapping was performed on sections made from a representative subset of these samples to further the initial characterization. Processing Apollo core 73001/2, creating an informative PE catalog that includes petrological and mineralogical data, and applying new and refined tools and technologies for sample analyses, are invaluable activities that will assist in circumventing any potential pitfalls, aid in the characterization of samples, and help in the assessment of how well any lunar material has been collected and preserved in the past [9]. This will aid in designing future sample collections and curation procedures and help to prepare for future human exploration and sampling missions such as Artemis. ANGSA core processing: a) Successful extrusion of 73002 in Nov. 2019; b) Successful opening of 73001 in March 2022; c) Sketch of dissection pass locations within the ANGSA cores. Representative XCT slices of the different lithologies observed in 73001/2. Brighter phases are more X-ray attenuating (i.e. higher average atomic number and/or more dense). All scale bars are 1 mm. (a) agglutinate; (b) regolith breccia; (c) Impact melt breccia (granulitic texture); (d) high-Ti basalt.