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Shape-Memory-Alloy-Based Launch Lock

This low-mass, low-power lock can be activated multiple times. NASA’s Jet Propulsion Laboratory, Pasadena, California Most NASA missions require the use of a launch lock for securing moving components during the launch or securing the payload before release. A launch lock is used to prevent unwanted motion and secure the controlled components. The current launch locks are based on pyrotechnic, electromechanical or NiTi-driven pin pullers that are one-time activation mechanisms. Generally, the use of piezoelectric activation provides high-precision nanometer accuracy, but they rely on friction to generate displacement. During launch, the generated vibrations can release the normal force between the actuator components, allowing the shaft’s free motion, which could result in damage to the actuated structures or instruments. This problem is common to other linear actuators that consist of a ball screw mechanism. There are many mechanisms that require the capability of being activated multiple times, and the disclosed concept addresses this need.

Posted in: Mechanics, Mechanical Components, Briefs, TSP

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Rotary Microspine Technology

A new design improves the mobility of manportable reconnaissance robots. NASA’s Jet Propulsion Laboratory, Pasadena, California Mobility for small, man-portable reconnaissance robots in the past has been limited with regard to obstacles like curbs, stairs, and vertical walls. A previous innovation overcame these obstacles by introducing rotary microspines — sharp hooks supported by elastic elements on a wheel. In this innovation, the work has been advanced with a new microspine design that eliminates the need for elastomer materials or the inserted hook.

Posted in: Mechanical Components, Briefs

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Rotary Microspine Technology

A new design improves the mobility of man-portable reconnaissance robots. NASA’s Jet Propulsion Laboratory, Pasadena, California Mobility for small, man-portable reconnaissance robots in the past has been limited with regard to obstacles like curbs, stairs, and vertical walls. A previous innovation overcame these obstacles by introducing rotary microspines — sharp hooks supported by elastic elements on a wheel. In this innovation, the work has been advanced with a new microspine design that eliminates the need for elastomer materials or the inserted hook.

Posted in: Mechanics, Mechanical Components, Briefs, TSP

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Percussive Augmenter of Rotary Drills for Operation as a Rotary-Hammer Drill

New rotary drill bits designed for percussive or ultrasonic hammering convert rotary drills/samplers into rotary-hammering drills/samplers. NASA’s Jet Propulsion Laboratory, Pasadena, California A piezoelectrically actuated percussive bit augments rotary drills to form a rotary-hammering drill/sampler. The Percussive Augmenter of Rotary Drills (PARoD) bit has two key modalities: one with vibrating free-mass and one without. In the first modality, the bit is designed to rotate the tip and transmit the impact of a free mass, while the complete bit turns as a single unit. In the second modality, the ultrasonic hammering action from the piezoelectric stack and the rotation from a commercial drill are applied directly to the drilled object. The PARoD tool includes slots to ensure that the tip of the bit does not rotate separately from the piezoelectric actuator. The bit employs electric and mechanical slip rings to transfer electric power, as well as water (for removal of cuttings and bit cooling), while freely turning the bit. The cooling plumbing can be connected to the related fixtures on heavy-duty commercial rotary drills.

Posted in: Mechanics, Mechanical Components, Briefs, TSP

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Non-Collinear Valve Actuator

This device separates the actions of the pneumatic actuator and the spring. Marshall Space Flight Center, Alabama Typical large aerospace valves use pneumatic actuators with large return springs to define a normal state. These springs are exclusively in line with the pneumatic actuator, and therefore are forced to have the same stroke and forces. These typical systems use either a large helical spring or a stack of Bellville springs. Each is long to ensure that the forces at the end of stroke are large enough to move the valve to the normal position with some margin. This invention reconfigures the actuator through the use of either a drag-link four-bar system or a cam to separate these two motions. The spring is allowed to have larger loads with significantly short spring stack length. This eliminates the need for long housings, heavy springs, and thus reduces the mass of the flight system. This configuration can be used for commercial valve actuators. Although commercial actuators generally do not have weight limitations, the reduction of the massive spring could reduce the cost of the product.

Posted in: Mechanics, Mechanical Components, Briefs

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Vibration and Thermal Cycling Apparatus for Cryogenic Tanks

Key design characteristics can be reliably and repeatedly tested together or separately as required by the design requirements. John F. Kennedy Space Center, Florida Understanding thermal and mechanical behaviors and their inter-dependencies of complex tank systems is crucial to making proper design decisions. Low-maintenance, high-performance systems are becoming more important as global energy demands and efficiency requirements increase.

Posted in: Physical Sciences, Briefs, TSP

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Integrated Rate Isolation Sensor

Sensor allows for fault detection and isolation using only two IMUs. Lyndon B. Johnson Space Center, Houston, Texas Some vehicles use an internal measurement unit (IMU) system to determine the speed, acceleration, orientation, position, and/or direction of movement of the vehicle. Vehicles used for high-availability or life-critical systems may employ a fault-tolerant IMU design. Typically, such vehicles use three or more IMUs to detect the failure of an IMU and isolate the failing IMU from the other functional IMUs. A fault-tolerant system having multiple IMUs pays an associated mass, power, and volume penalty for each additional IMU. The mass/power/volume (M/P/V) of a fault-tolerant IMU system is the M/P/V of an individual IMU multiplied by the number of IMUs employed to do fault tolerance. Furthermore, each additional IMU adds to the cost of a fault-tolerant system.

Posted in: Physical Sciences, Briefs

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