Using an analog lunar sample return mission to grow a lunar sample community and prepare for human return to the Moon’s surface. An update on the progress of the ANGSA initiative.

Introduction:

Analyses of samples returned by the Apollo Program have provided fundamental insights into the origin-history of the Earth-Moon system and how planets and solar systems work. Several special samples that were collected or preserved in unique containers or environments (e.g., Core Sample Vacuum Container (CSVC), frozen samples) have remained unexamined by standard or advanced analytical approaches. The Apollo Next Generation Sample Analysis (ANGSA) initiative was designed to examine a subset of these samples. The initiative was purposely designed to function as a participating scientist program for these samples, and as a preparation for new sample return missions from the Moon (e.g., Artemis) with processing, preliminary examination (PE), and analyses utilizing new and advanced technologies, lunar mission observations, and post-Apollo science concepts. ANGSA links the first generations of lunar explorers (Apollo) with future generations of lunar explorers (Artemis) [1-4].

Progress and Results:

Teamwork for gas extraction from CSVC 73001: To extract any potential gas phase from the CSVC, the European Space Agency (ESA) designed, built, tested, and delivered to JSC a CSVC piercing tool. To collect-store the gas phase, WUStL designed, built, and delivered to JSC a gas manifold system. Together these tools were used to open and sample the CSVC. Preliminary analyses of these gases are being carried out at UNM (Z. Sharp) and WUStL (R. Parai), which will determine whether a lunar component can be detected in the gas.

Extrusion of 73001: Following extraction of gas, the lower part of the double drive tube (73001) was imaged (µXCT, multi-spectral imaging), extruded, dissected, sieved, and examined (Pass 1 and 2). Pass 3 will remain unsieved and will be a target for PE by early career ANGSA scientists-engineers. ANGSA team members participated in the PE of 73002.

Frozen samples: The cold curation facility for processing Apollo 17 frozen samples was approved in mid-December 2021. These samples were processed and allocated in early 2022. Studies are advancing to define differences in preservation of (a) volatiles between frozen and unfrozen samples; (b) thermoluminescence kinetics in lunar samples [e.g., 5]; and (c) chronology.

Stratigraphy of 73001-73002: The stratigraphy of the double drive tube has been examined by multiple approaches. For 73001-73002, the stratigraphy was documented by µXCT imaging [6], reflectance properties [7,8], I_S/FeO [8], major, minor, and trace element geochemistry [9,10], grain size/modal proportions [8,11,12], and continuous thin sections [13].

 µXCT imaging of lithic fragments: Lithic fragments >4 mm in size were removed from the double drive tube during sampling passes 1-2 (73001-73002); from unsieved Pass 3 > 1cm fragments were removed.  µXCT images of hundreds of these lithic fragments were produced. Fragments include a variety of breccias (some with a significant number of spherical glasses), high-Ti basalts with different cooling histories, a variety of “lower-Ti” basalts, and unique lithologies presumably derived from the South Massif. The ANGSA lithic analysis group is carrying out collaborative studies of these fragments [6,14].

Less than 1mm lithic fragments: During processing of Passes 1 and 2 from the double drive tube, samples were sieved into > 1 mm and < 1 mm size fractions. The < 1 mm size fractions were further sieved into 1000-500, 500-250, 250-150, 150-90, 90-20, and <20µm size fractions for selected intervals. In addition to determining modes of each size fraction within the stratigraphy, lithic fragments were also classified and documented. Impact melt rocks and breccias were abundant. Igneous lithologies include ferroan anorthosites, Mg-suite, “felsites”, low-Ti basalts, pyroclastic glasses, and a variety of high-Ti basalts [11,12,15]. Observations (e.g., volatiles, stable isotopes, organics, cosmogenic radionuclides, space weathering) were placed within the context of core stratigraphy [e.g., 16-21].

References: [1] Shearer et al. (2020) 51^st LPSC abst.#1181  [2] Shearer (2008) Presentation to CAPTEM. [3] Shearer et al. (2019) 50^th LPSC abst. #1412. [4] G. Lofgren (2007) personal communication. [5] Sehlke et al (2022) 53^rd LPSC abst. #1267.[6] Zeigler et al. (2022) 53^rd LPSC abst.#2890. [7] Sun et al. (2022) 53^rd LPSC abst. #1890. [8] Morris et al. (2022) 53^rd LPSC abst. #1849. [9] Neuman et al. (2022)  53^rd LPSC abst.#1389. [10]  Valenciano et al. (2022) 53^rd LPSC abst.#2869. [11] Simon et al. (2022) 53^rd LPSC abst.#2211. [12] Cato et al. (2022) 53^rd LPSC abst.#2215. [13] Bell et al. (2022) 53^rd LPSC abst.#1947. [14] Yen et al (2022) 53^rd LPSC abst.#1547. [15] Valencia et al. (2022) 53^rd LPSC abst#2608. [16] Cano et al. (2021) AGU Fall Meeting abst.; [17] Gargano et al. (2022) 53^rd LPSC abst#2450 . [18] Recchuiti et al (2022) 53^rd LPSC abst.#2193. [19] Elsila et al. (2022) 53^rd LPSC abst.# 1212. [20] Welten et al. (2022) 53^rd LPSC abst.#2389. [21] McFadden et al. (2022) 53^rd LPSC abst. #1539.