Planning Implications Related to Sterilization-Sensitive Science Investigations Associated with Mars Sample Return (MSR).

The NASA/ESA Mars Sample Return (MSR) Campaign seeks to establish whether life on Mars existed where and when environmental conditions allowed. Laboratory measurements on the returned samples are useful if what is measured is evidence of phenomena on Mars rather than of the effects of sterilization conditions. This report establishes that there are categories of measurements that can be fruitful despite sample sterilization and other categories that cannot.

Preliminary Planning for Mars Sample Return (MSR) Curation Activities in a Sample Receiving Facility (SRF).

The Mars Sample Return Planning Group 2 (MSPG2) was tasked with identifying the steps that encompass all the curation activities that would happen within the MSR Sample Receiving Facility (SRF) and any anticipated curation-related requirements. An area of specific interest is the necessary analytical instrumentation. The SRF would be a Biosafety Level-4 facility where the returned MSR flight hardware would be opened, the sample tubes accessed, and the martian sample material extracted from the tubes.

Science and Curation Considerations for the Design of a Mars Sample Return (MSR) Sample Receiving Facility (SRF).

The most important single element of the "ground system" portion of a Mars Sample Return (MSR) Campaign is a facility referred to as the Sample Receiving Facility (SRF), which would need to be designed and equipped to receive the returned spacecraft, extract and open the sealed sample container, extract the samples from the sample tubes, and implement a set of evaluations and analyses of the samples. One of the main findings of the first MSR Sample Planning Group (MSPG, 2019a) states that "The scientific community, for reasons of scientific quality, cost, and timeliness, strongly prefers that as many sample-related investigations as possible be performed in PI-led laboratories outside containment." There are many scientific and technical reasons for this preference, including the ability to utilize advanced and customized instrumentation that may be difficult to reproduce inside in a biocontained facility, and the ability to allow multiple science investigators in different labs to perform similar or complementary analyses to confirm the reproducibility and accuracy of results.

Rationale and Proposed Design for a Mars Sample Return (MSR) Science Program.

The Mars Sample Return (MSR) Campaign represents one of the most ambitious scientific endeavors ever undertaken. Analyses of the martian samples would offer unique science benefits that cannot be attained through orbital or landed missions that rely only on remote sensing and measurements, respectively. As currently designed, the MSR Campaign comprises a number of scientific, technical, and programmatic bodies and relationships, captured in a series of existing and anticipated documents.

The Scientific Importance of Returning Airfall Dust as a Part of Mars Sample Return (MSR).

Dust transported in the martian atmosphere is of intrinsic scientific interest and has relevance for the planning of human missions in the future. The MSR Campaign, as currently designed, presents an important opportunity to return serendipitous, airfall dust. The tubes containing samples collected by the Perseverance rover would be placed in cache depots on the martian surface perhaps as early as 2023-24 for recovery by a subsequent mission no earlier than 2028-29, and possibly as late as 2030-31.

Multiple early-formed water reservoirs in the interior of Mars.

The abundance and distribution of water within Mars through time plays a fundamental role in constraining its geological evolution and habitability. The isotopic composition of martian hydrogen provides insights into the interplay between different water reservoirs on Mars. However, D/H (deuterium/hydrogen) ratios of martian rocks and of the martian atmosphere span a wide range of values.

Silica-rich volcanism in the early solar system dated at 4.565 Ga.

The ranges in chemical composition of ancient achondrite meteorites are key to understanding the diversity and geochemical evolution of planetary building blocks. These achondrites record the first episodes of volcanism and crust formation, the majority of which are basaltic. Here we report data on recently discovered volcanic meteorite Northwest Africa (NWA) 11119, which represents the first, and oldest, silica-rich (andesitic to dacitic) porphyritic extrusive crustal rock with an Al-Mg age of 4564.

Unique meteorite from early Amazonian Mars: water-rich basaltic breccia Northwest Africa 7034.

We report data on the martian meteorite Northwest Africa (NWA) 7034, which shares some petrologic and geochemical characteristics with known martian meteorites of the SNC (i.e., shergottite, nakhlite, and chassignite) group, but also has some unique characteristics that would exclude it from that group.

Compressibility of water in magma and the prediction of density crossovers in mantle differentiation.

Hydrous silicate melts appear to have greater compressibility relative to anhydrous melts of the same composition at low pressures (<2GPa); however, at higher pressures, this difference is greatly reduced and becomes very small at pressures above 5GPa. This implies that the pressure effect on the partial molar volume of water in silicate melt ( partial differentialV-H2O/ partial differentialP) is highly dependent on pressure regime. Thus, H2O can be thought of as the most compressible 'liquid oxide' component in silicate melt at low pressure, but at high pressure its compressibility resembles that of other liquid oxide components.