title: The sample handling system for the Mars Icebreaker Life mission: from dirt to data.
abstract: The Mars Icebreaker Life mission will search for subsurface life on Mars. It consists of three payload elements: a drill to retrieve soil samples from approximately 1 m below the surface, a robotic sample handling system to deliver the sample from the drill to the instruments, and the instruments themselves. This paper will discuss the robotic sample handling system. Collecting samples from ice-rich soils on Mars in search of life presents two challenges: protection of that icy soil--considered a "special region" with respect to planetary protection--from contamination from Earth, and delivery of the icy, sticky soil to spacecraft instruments. We present a sampling device that meets these challenges. We built a prototype system and tested it at martian pressure, drilling into ice-cemented soil, collecting cuttings, and transferring them to the inlet port of the SOLID2 life-detection instrument. The tests successfully demonstrated that the Icebreaker drill, sample handling system, and life-detection instrument can collectively operate in these conditions and produce science data that can be delivered via telemetry--from dirt to data. Our results also demonstrate the feasibility of using an air gap to prevent forward contamination. We define a set of six analog soils for testing over a range of soil cohesion, from loose sand to basalt soil, with angles of repose of 27° and 39°, respectively. Particle size is a key determinant of jamming of mechanical parts by soil particles. Jamming occurs when the clearance between moving parts is equal in size to the most common particle size or equal to three of these particles together. Three particles acting together tend to form bridges and lead to clogging. Our experiments show that rotary-hammer action of the Icebreaker drill influences the particle size, typically reducing particle size by ≈ 100 μm.
authors.affiliation: NASA Ames Research Center, Moffett Field, California 94035, USA. arwen.i.dave@nasa.gov
authors.forename: Arwen
authors.initials: A
authors.lastname: Davé
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Thompson
authors.forename: Christopher P
authors.initials: CP
authors.lastname: McKay
authors.forename: Carol R
authors.initials: CR
authors.lastname: Stoker
authors.forename: Kris
authors.initials: K
authors.lastname: Zacny
authors.forename: Gale
authors.initials: G
authors.lastname: Paulsen
authors.forename: Bolek
authors.initials: B
authors.lastname: Mellerowicz
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Glass
authors.forename: David
authors.initials: D
authors.lastname: Willson
authors.forename: Rosalba
authors.initials: R
authors.lastname: Bonaccorsi
authors.forename: Jon
authors.initials: J
authors.lastname: Rask
mesh_terms: D004867:Equipment Design / Q000379:methods*; D018559:Exobiology / Q000295:instrumentation* / Q000379:methods; D005118:Extraterrestrial Environment / Q000737:chemistry*; D007053:Ice; D018535:Mars; D012987:Soil / Q000737:chemistry*; D018531:Spacecraft / Q000295:instrumentation*; D013686:Telemetry; D014481:United States; D018557:United States National Aeronautics and Space Administration
chemical_list: D007053:Ice; D012987:Soil