A study of the curation protocol by sample analysis working team (SAWT)in Martian Moons eXploration (MMX) project*R. Fukai1, T. Usui2, W. Fujiya3, Y. Takano4, K. Bajo5, A. Beck6, E. Bonato7, N. L. Chabot8, Y. Furukawa9, H. Genda10, M.
Koike11, M. Matsuoka12, Y. N. Miura2, F. Moynier13, S. S. Russell14, M. E. Zolensky15, H. Sugahara1, S. Tachibana1,2, K.
Sakamoto1, and M. Abe1
12Japan Aerospace Exploration Agency, The University of Tokyo, 3Ibaraki University, 4Japan Agency for Marine-Earth Scienceand Technology, 5Hokkaido University, 6Marietta College, 7German Aerospace Center, 8Johns Hopkins University, 9Tohoku
University, 10Tokyo Tech, 11Hiroshima University, 12National Institute of Advanced Industrial Science and Technology, 13Institutde physique du globe de Paris, 14Natural History Museum, 15National Aeronautics and Space Administration
Japan Aerospace Exploration Agency (JAXA) will launch a spacecraft in 2024 for a sample return mission from Phobos(Martian Moons eXploration: MMX). The major scientific goals of MMX are to constrain (1) the origin of Phobos and Deimosand (2) the evolution of the Mars-moon system [1]. The touchdown operations are planned to be performed twice at different
landing sites on the Phobos surface to collect > 10 g of the surface materials [2]. After the return to the Earth, the Phobos
samples will be collected from the individual sample canisters and introduced to the clean chamber installed at ISAS (Instituteof Space and Astronautical Science). The Sample Analysis Working Team (SAWT) of MMX designed the procedure ofPhobos sample analysis mainly conducted by the initial analysis teams [3]. For the next step, the SAWT will define theprocedure of the curation process (mostly non-destructive analysis) of the Phobos samples, which will be presented here.
The protocols of the Phobos sample curation are illustrated in figure 1. First, the headspace gas from the sample
container will be collected during the Quick Analysis phase. The Quick Analysis will be operated by the sampler and curation
teams in ISAS/JAXA. The terrestrial leak and contamination from the sampling systems will be tested using a quadrupole
mass spectrometer equipped with a gas sampling system. Second, the bulk Phobos sample will be observed in the cleanchamber under purified-N2 gas with an ambient condition (Pre-basic Characterization) within three weeks. This phase will beoperated by the curation team in ISAS/JAXA and the instrument team of the MMX mission. The consistency between the datafrom the instruments in the clean chamber and the spacecraft will then be evaluated.
Subsequently, the curation will distribute the small amount of Phobos samples to the Initial analysis team of MMX to
conduct the "Preliminary Examination". The objectives of the preliminary examination are to provide (1) feedback on thesubsequent sample allocation process, (2) preliminary scientific results that will address parts of MMX mission goals, and (3)evaluation of the sampling system and terrestrial alteration on Phobos samples. Because multiple models are proposed for theorigin of Phobos [1] (e.g., giant impact, the capture of asteroids), the chemical and mineralogical characteristics of Phobos
must be assessed before the allocation of the samples to the individual Initial Analysis teams. The Preliminary Examination
will start after about 1 month from the sample return. Simultaneously, the curation team in JAXA will observe the individualgrains and aliquots of the samples in the clean chamber (Basic Characterization). The results obtained in Preliminary
Examination will be investigated with several SSTs (Science Strategy Teams). Based on the results, the curation team will
decide on the sample amounts to allocate to the Initial Analysis team. After 6 months from the Preliminary Examination, Initial
Analysis will be started to perform the comprehensive analysis for Phobos samples within 1 year.
The curation protocols the SAWT proposes here are partly based on those in Hayabusa & Hayabusa2 missions [4].
However, our strategy enables us to utilize larger amounts of return samples compared to the previous sample return missions.
Also, the chemical/mineralogical characteristics of Phobos will be quickly understood throughout the non-destructive anddestructive analyses in the curation process.

Fig. 1: Curation protocols for the Phobos samples.

References: [1] K. Kuramoto et al. (2022) Earth, Planets, and Space, 74 (12). [2] T. Usui et al. (2020) Space Science Review,
216 (49). [3] W. Fujiya et al. (2021) Earth, Planets and Space, 73 (120). [4] T. Yada et al. (2022) Nature Astronomy, 6, 214.