Proceedings of the 40th Aerospace Mechanisms Symposium

The Aerospace Mechanisms Symposium (AMS) provides a unique forum for those active in the design, production and use of aerospace mechanisms. A major focus is the reporting of problems and solutions associated with the development and flight certification of new mechanisms. Organized by the Mechanisms Education Association, responsibility for hosting the AMS is shared by the National Aeronautics and Space Administration and Lockheed Martin Space Systems Company (LMSSC). Now in its 40th symposium, the AMS continues to be well attended, attracting participants from both the U.S. and abroad. The 40th AMS, hosted by the Kennedy Space Center (KSC) in Cocoa Beach, Florida, was held May 12, 13 and 14, 2010. During these three days, 38 papers were presented. Topics included gimbals and positioning mechanisms, CubeSats, actuators, Mars rovers, and Space Station mechanisms. Hardware displays during the supplier exhibit gave attendees an opportunity to meet with developers of current and future mechanism components. The use of trade names of manufacturers in this publication does not constitute an official endorsement of such products or manufacturers, either expressed or implied, by the National Aeronautics and Space Administratio

Detection and Analysis of Martian Low-Temperature Geochemistry

The history of Mars is encoded in the geochemistry of ancient sedimentary Martian rocks and secondary phases. Recent landed missions have provided unparalleled datasets with which to investigate this geochemistry. Accordingly, this thesis is concerned primarily with the in-situ analysis of low-temperature Martian geochemical processes by landed missions, and the attendant Earth-based studies which enrich those in-situ investigations. There are five main studies reported here. The first is an analysis of a Mars-analog environment on Earth. Datasets similar to those that will be produced by the upcoming Mars-2020 rover are used to evaluate the ability of the rover to reconstruct a known paleoenvironment, to identify reference datasets that require further development, and to suggest operational modes that most efficiently use the rover’s resources. The second study is an in-situ noble gas analysis using the SAM instrument on the Curiosity rover to investigate a jarosite-containing sample using a two-step heating analysis for K-Ar dating. The jarosite likely formed at 2.12±0.36 Ga while plagioclase in the sample formed at 4.07 ± 0.63 Ga, indicating that liquid water interactions continued in Gale crater well past the end of the Hesperian period. The following chapter details another noble gas analysis, focusing on cosmogenic dating of surface exposure. In contrast to <100 Ma exposure ages observed at the floor of Gale crater, exposure ages exceeding 1 Ga are detected on the flanks of Mount Sharp. These ages indicate Mount Sharp formed during the Hesperian and has been largely unchanged in the intervening 3.1 Ga. The next study is a reevaluation of the data used to identify the presence of perchlorate in Gale crater. These data suggest that perchlorate is indeed present, but that it must be Amazonian in age, suggesting that rare surface wetting events have caused leaching of this soluble ion into the bedrock. The final study reports the development of a technique for measuring the isotopes in perchlorate using Orbitrap mass spectrometry on Earth, allowing investigation of the formation processes that impact the chlorine isotope ratio of this molecule on both Earth and Mars

Mars Science Laboratory CHIMRA/IC/DRT Flight Software for Sample Acquisition and Processing

The design methodologies of using sequence diagrams, multi-process functional flow diagrams, and hierarchical state machines were successfully applied in designing three MSL (Mars Science Laboratory) flight software modules responsible for handling actuator motions of the CHIMRA (Collection and Handling for In Situ Martian Rock Analysis), IC (Inlet Covers), and DRT (Dust Removal Tool) mechanisms. The methodologies were essential to specify complex interactions with other modules, support concurrent foreground and background motions, and handle various fault protections. Studying task scenarios with multi-process functional flow diagrams yielded great insight to overall design perspectives. Since the three modules require three different levels of background motion support, the methodologies presented in this paper provide an excellent comparison. All three modules are fully operational in flight