Mechanical & Fluid Systems

Shape Memory Alloy Rock Splitter

This splitter can be applied wherever explosive or impact techniques cannot be used. John H. Glenn Research Center, Cleveland, Ohio A working prototype of a non-explosive, static rock splitter for space exploration using shape memory alloys (SMAs) as the driving member also has terrestrial applications. The static, compact, non-explosive shape memory alloy rock splitter (SMARS) was designed for sampling geological deposits, including planetary bodies such as the Moon, Mars, and near-Earth asteroids (Figure 1). The splitter employs high-temperature SMAs that generate extremely large forces in response to thermal loads, while providing a compact and cost-effective method for fracturing rocklike materials and minerals when compared to hydraulic or explosive-based alternatives. The active elements, in the form of pre-shaped cylindrical pellets, are used in conjunction with custom-built DC voltage heaters placed in boreholes.

Posted in: Briefs

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Passive, Low-Insertion-Force/High-Retention-Force Cam Plug Design for Sample Tube Sample Caging

This plug could be used for soil and sediment samples in petroleum and mining industries, or to plug products of various sizes tightly in tubes for shipping. NASA’s Jet Propulsion Laboratory, Pasadena, California AMars “sample caching rover” mission designed to collect, document, and package samples for future collection and return to Earth was recommended as the highest-priority mission for 2013–2022 by the 2011 Planetary Decadal Survey. A key premise of the Mars 2020 rover, which will gather samples for potential future return, is that it should be possible for the samples to be packaged and left on Mars for an extended period of time (at least five Mars years) without loss of scientific value. Two particularly important characteristics of a sample are the structure and relative positioning of the rock fragments and grains. These characteristics can be affected by shock and vibration that could fracture the sample and create relative movement among the fragments and grains, and therefore cause loss of valuable scientific information.

Posted in: Briefs

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Design Support and Analysis Tool for Pyrotechnically Actuated Valves

Lyndon B. Johnson Space Center, Houston, Texas This software predicts flow through the initiator of a Primer Chamber Assembly Valve. These valves exhibited a potential failure mode for specific operating conditions where dual simultaneous firings of the initiator occurred. The software tool was able to identify a fluid dynamic source for this potential failure mode. Furthermore, the software was also used to provide new conceptual designs that may alleviate or eliminate these failure modes.

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Deployable Extra-Vehicular Activity Platform (DEVAP) for Planetary Surfaces

Potential applications include stable work ramps for vehicles, vessels, or portable shelters. John F. Kennedy Space Center, Florida The Deployable Extra-Vehicular Activity Platform (DEVAP) is a staging platform for egress and ingress attached to a lunar, Mars, or planetary surface habitat airlock, suitlock, or port. The DEVAP folds up into a compact package for transport, and deploys manually from its attached location to provide a ramp and staging platform for extravehicular activities (see figure).

Posted in: Briefs

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Two-Phase Thermal Switch

The switching mechanism is passively triggered by the temperature of the heat source. Marshall Space Flight Center, Alabama There is a wide range of spacecraft thermal management applications that require variable conductance devices such as thermal switches. These switches are used to help maintain the heat source (electronics) temperature under varying thermal loads and varying thermal environments. These applications include satellites and Lunar and Mars landers and rovers, as well as future human spacecraft that may transit through both the cold environment of deep space and warm transient environments such as low lunar orbit.

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Save Your Assembly Space and Weight with Smalley Wave Springs

Smalley Wave Springs offer the unique advantage of space savings when used to replace coil springs. By reducing spring operating height, wave springs also produce a decrease in the spring cavity and assembly size.

Posted in: White Papers, Machinery & Automation, Robotics

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Reliable VFD Cables Boost Productivity, Minimize Downtime

From fans and blowers to 24/7 production line equipment, variable frequency drives (VFDs) are a mainstay of the industrial world due to their remarkable ability to improve the efficiency of motor-driven equipment. As part of a complete VFD package, high quality cable is one of the most important components in terms of achieving maximum productivity and minimizing downtime. When designing a robust VFD cable, the materials used in its production are critical to ensuring that the cable’s electrical properties will guarantee peak performance. For system engineers and others involved in specifying VFDs, cable quality should be one of the most decisive factors.

Posted in: White Papers

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