@article{9b810abb41bd4b9588d34bf3401f623f,
title = "Assessing the Sampleability of Bennu{\textquoteright}s Surface for the OSIRIS-REx Asteroid Sample Return Mission",
abstract = "NASA{\textquoteright}s first asteroid sample return mission, OSIRIS-REx, collected a sample from the surface of near-Earth asteroid Bennu in October 2020 and will deliver it to Earth in September 2023. Selecting a sample collection site on Bennu{\textquoteright}s surface was challenging due to the surprising lack of large ponded deposits of regolith particles exclusively fine enough (≤2cm diameter) to be ingested by the spacecraft{\textquoteright}s Touch-and-Go Sample Acquisition Mechanism (TAGSAM). Here we describe the Sampleability Map of Bennu, which was constructed to aid in the selection of candidate sampling sites and to estimate the probability of collecting sufficient sample. “Sampleability” is a numeric score that expresses the compatibility of a given area{\textquoteright}s surface properties with the sampling mechanism. The algorithm that determines sampleability is a best fit functional form to an extensive suite of laboratory testing outcomes tracking the TAGSAM performance as a function of four observable properties of the target asteroid. The algorithm and testing were designed to measure and subsequently predict TAGSAM collection amounts as a function of the minimum particle size, maximum particle size, particle size frequency distribution, and the tilt of the TAGSAM head off the surface. The sampleability algorithm operated at two general scales, consistent with the resolution and coverage of data collected during the mission. The first scale was global and evaluated nearly the full surface. Due to Bennu{\textquoteright}s unexpected boulder coverage and lack of ponded regolith deposits, the global sampleability efforts relied heavily on additional strategies to find and characterize regions of interest based on quantifying and avoiding areas heavily covered by material too large to be collected. The second scale was site-specific and used higher-resolution data to predict collected mass at a given contact location. The rigorous sampleability assessments gave the mission confidence to select the best possible sample collection site and directly enabled successful collection of hundreds of grams of material.",
keywords = "Asteroid exploration, Bennu, Landing site selection, Spacecraft safety, Surface topography",
author = "Walsh, {Kevin J.} and Bierhaus, {Edward B.} and Lauretta, {Dante S.} and Nolan, {Michael C.} and Ballouz, {Ronald Louis} and Bennett, {Carina A.} and Jawin, {Erica R.} and Barnouin, {Olivier S.} and Kevin Berry and Burke, {Keara N.} and Bella Brodbeck and Rich Burns and Clark, {Benton C.} and Clark, {Beth E.} and Saverio Cambioni and Connolly, {Harold C.} and Daly, {Michael G.} and Marco Delbo and DellaGiustina, {Daniella N.} and Dworkin, {Jason P.} and Enos, {Heather L.} and Emery, {Josh P.} and Pamela Gay and Golish, {Dathon R.} and Hamilton, {Victoria E.} and Rachel Hoover and Michael Lujan and Timothy McCoy and Mink, {Ronald G.} and Moreau, {Michael C.} and Jennifer Nolau and Jacob Padilla and Maurizio Pajola and Polit, {Anjani T.} and Robbins, {Stuart J.} and Ryan, {Andrew J.} and Selznick, {Sanford H.} and Stephanie Stewart and Wolner, {Catherine W.V.}",
note = "Funding Information: We thank the entire OSIRIS-REx team for the discussions and hard work that made this effort possible. We thank Rose Bandrowski (University of Arizona), Vivian Morrison (University of Arizona), Natalie Wagner (University of Arizona), Robert Melikyan (Ithaca College), Daniela McCarty (University of Central Florida) and Savanna Salazar (University of Arizona), who all contributed time counting particles to support this effort. This material is based upon work supported by NASA under Contract NNM10AA11C issued through the New Frontiers Program. M. Pajola was supported for this research by the Italian Space Agency (ASI) under the ASI-INAF agreement no. 2017-37-H.0. All instrument data from the OSIRIS-REx mission are archived in the Planetary Data System (PDS) at https://sbn.psi.edu/pds/resource/orex/. Sampleability map[s] will be delivered to the PDS as an OSIRIS-REx special product. DTMs of Bennu are available via the Small Body Mapping Tool at http://sbmt.jhuapl.edu/. Funding Information: This material is based upon work supported by NASA under Contract NNM10AA11C issued through the New Frontiers Program. M. Pajola was supported for this research by the Italian Space Agency (ASI) under the ASI-INAF agreement no. 2017-37-H.0. Publisher Copyright: {\textcopyright} 2022, The Author(s).",
year = "2022",
month = jun,
doi = "10.1007/s11214-022-00887-2",
language = "English (US)",
volume = "218",
journal = "Space Science Reviews",
issn = "0038-6308",
publisher = "Springer Netherlands",
number = "4",
}