Is a Linear or a Walkabout Protocol More Efficient When Using a Rover to Choose Biologically Relevant Samples in a Small Region of Interest?

Abstract

We conducted a field test at a potential Mars analog site to provide insight into planning for future robotic missions such as Mars 2020, where science operations must facilitate efficient choice of biologically relevant sampling locations. We compared two data acquisition and decision-making protocols currently used by Mars Science Laboratory: (1) a linear approach, where sites are examined as they are encountered and (2) a walkabout approach, in which the field site is first examined with remote rover instruments to gain an understanding of regional context followed by deployment of time-and power-intensive contact and sampling instruments on a smaller subset of locations. The walkabout method was advantageous in terms of both the time required to execute and a greater confidence in results and interpretations, leading to enhanced ability to tailor follow-on observations to better address key science and sampling goals. This advantage is directly linked to the walkabout method's ability to provide broad geological context earlier in the science analysis process. For Mars 2020, and specifically for small regions to be explored (e.g., <1 km 2), we recommend that the walkabout approach be considered where possible, to provide early context and time for the science team to develop a coherent suite of hypotheses and robust ways to test them.

Using Rover-analogous Methodology to Discriminate between Volcanic and Sedimentary Origins in Successions Dominated by Igneous Composition

“…Additionally, the Tiger team identified key facies in some units that helped establish environmental context (e.g., the identification of large-scale cross-bedding and varved mudstones in unit 1, which enhanced the interpretation of the volcano-glacial setting of this unit). These results are fully consistent with previous GHOST tests (Yingst et al 2011(Yingst et al , 2014(Yingst et al , 2016(Yingst et al , 2020(Yingst et al , 2022, in which Rover teams gathered sufficient field data to make accurate first-order interpretations but sometimes lacked the information to make fine-scale interpretations, such as small-scale variability in depositional conditions reflected in subtle changes in depositional style or lateral variability in rock characteristics.…”

“…However, this same motion with a rover is challenging to implement and requires significant resources. One of the great advantages that our earlier experiments found was that the reconnaissance pass methodology builds time into the operations cycle that permits assessment and identification of more optimal potential samples (Yingst et al 2016(Yingst et al , 2020(Yingst et al , 2022. In the same way, making a lateral exploration of an area prior to obtaining contact science (even if over just a few meters) might help discern these types of structures.…”

“…In recent GHOST tests, we have tested tactical (1-4 Martian days, or "sols") and strategic (weeks or more) data acquisition scenarios used by MSL and Mars 2020, by executing multiple traverses with multiple "rovers" (Yingst et al 2016(Yingst et al , 2020 and determining how many sols would be required to execute each team's activities. A primary goal in these tests was to determine the most time-and resource-efficient scenarios for interrogating a site while meeting a specific science objective.…”

Testing Rover Science Protocols to Identify Possible Biosignatures on Mars: Achieving Sampling Goals Under a Highly Constrained Time Line

“…Data acquisition teams were structured similarly to previous tests (Yingst et al , 2016 , 2020 ). One individual served as the independent site expert, reconnoitering the site and providing remote data sets for the teams to use in mission planning.…”

“…By contrast, the GeoHeuristic Operational Strategies Testing (GHOST) program isolates the science operations' decision-making process by using commercial, off-the-shelf technology, minimizing variables related to rover and equipment function (Yingst et al , 2018 , 2020 ). Previous GHOST field tests have focused on investigating the relative efficiency of executing all science activities on a single traverse, compared with using a reconnaissance pass—a method of traverse previously termed a “walkabout,” in which the remote instruments are used to assess the site, and then the site is traversed again, with the more resource-intensive instruments used on a subset of high-priority targets—before detailed contact science on a subset of high-value targets (Yingst et al , 2016 , 2018 , 2020 ).…”