233 Mars Science Laboratory Sample Acquisition, Sample Processing and Handling:  Subsystem Design and Test Challenges 

Louise Jandura * 

Abstract   The Sample Acquisition/Sample Processing and Handli ng subsystem for the Mars  Science Laboratory is  a highly-mechanized, Rover-based sampling system  that acquires powdered rock and regolith samples  from the Martian surface, sorts the samples into fi ne particles through sieving, and delivers small portions  of the powder into two science instruments insi de the Rover. SA/SPaH utilizes 17 actuated degrees-offreedom to perform the functions needed to produce 5 sample pathways in support of the scientific investigation on Mars. Both hardware redundancy and functional redundancy are employed in configuring  this sampling system so some functionality is retained even with the loss of a degree-of-freedom.  Intentional dynamic environments are created to move sample while vibration isolators attenuate this environment at the sensitive instruments located near the dynamic sources.  In addition to the typical flight  hardware qualification test program, two additional types of testing are essential for this kind of sampling  system: characterization of the intentionally-created dynamic envir onment and testing of the sample  acquisition and processing hardware functions using Mars analog materials in a low pressure environment. The overall subsystem design and confi guration are discussed along with some of the  challenges, tradeoffs, and lessons learned in the areas  of fault tolerance, intentional dynamic  environments, and special testing.   Introduction 

The Sample Acquisition/Sample Processing and Hand ling (SA/SPaH) subsystem for the Mars Science  Laboratory (MSL) is a Rover-based sampling system c apable of operating in the cold temperature, low  pressure, reduced gravity environment of Mars (Figur e 1). Scheduled to launch in 2011, the Rover carries  a suite of ten scientific instru ments capable of making remote and in situ  measurements of the  environment and of the rocks and regolith acquir ed by SA/SPaH. The SA/SPaH acquires rock and  regolith samples from the Martian surface, proce sses them into fine particles through sieving, and  delivers small portions of the powder into the two analytical instruments, SAM and Chemin, inside the  Rover. SAM analyzes the chemistry relevant for lif e, including carbon chemistry, and Chemin determines  the mineralogy of the delivered powder. The SA/SPaH c an acquire powder from rocks at depths of 20 to  50 mm and can also pick up loose regolith with its scoop.  The overall scientific goal of the mission is to  assess the habitability, both past and present, of the si tes visited by the Rover. The duration of the  primary mission is one Martian year (approximately two Earth years.)    In order to perform its main functions of examining, acquiring, processing, and delivering samples for scientific investigation on Mars, SA/SPaH consists  of a 5 degree-of-freedom, 2-meter-long Robotic Arm  which can manipulate the Turret-mounted tools and inst ruments. The Turret (Figure 2) is approximately  600 millimeters in diameter and contains 5 devices: a powder acquisition Drill, a scooping, sieving, and  portioning device called CHIMRA, a Dust Removal Tool  (DRT) for clearing the surface of scientific  targets, and two contact instruments, APXS and MAHLI, mounted on vibration isolators. APXS, an Alpha Particle X-ray Spectrometer, and MAHLI, an imager, are two of the ten scientific  instruments on MSL.  

                                                  * Jet Propulsion Laboratory, California In stitute of Technology, Pasadena, CA 

Proceedings of the 40th Aerospace Mechanisms Symposium, N ASA Kennedy Space Center, May 12-14, 2010   NASA/CP-2010-216272