Mechanical Components

Uniform Dust Distributor for Testing Radiative Emittance of Dust-Coated Surfaces

This device could be used in applying uniform amounts of dust on surfaces to which coatings may be applied. This apparatus distributes dust (typical of the Martian surface) in a uniform fashion on the surface of multiple samples simultaneously. The primary innovation is that the amount of dust deposited on the multiple surfaces can be controlled by the time that the apparatus operates, and each sample will be subject to the same amount of dust deposition. The exact weight of dust that is added per unit of sample area is determined by the use of slides that can be removed sequentially after each dusting.

Posted in: Mechanics, Mechanical Components, Briefs, TSP

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Multi-Mission Radioisotope Thermoelectric Generator Heat Exchangers for the Mars Science Laboratory Rover

These heat exchangers can be used in any application in which heat loads must be simultaneously collected and rejected from opposite sides of the same structure. The addition of the Multi-Mission Radioisotope Thermoelectric Generator (MMRTG) to the Mars Science Laboratory (MSL) Rover requires an advanced thermal control system that is able to both recover and reject the waste heat from the MMRTG as needed in order to maintain the onboard electronics at benign temperatures despite the extreme and widely varying environmental conditions experienced both on the way to Mars and on the Martian surface (See figure).

Posted in: Mechanics, Mechanical Components, Briefs

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MicroProbe Small Unmanned Aerial System

The MicroProbe unmanned aerial system (UAS) concept incorporates twin electric motors mounted on the vehicle wing, thus enabling an aerodynamically and environmentally clean nose area for atmospheric sensors. A payload bay is also incorporated in the fuselage to accommodate remote sensing instruments.

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Implementation of a Non-Metallic Barrier in an Electric Motor

Electric motors that run in pure oxygen must be sealed, or “canned,” for safety reasons to prevent the oxygen from entering into the electrical portion of the motor. The current canning process involves designing a metallic barrier around the rotor to provide the separation. This metallic barrier reduces the motor efficiency as speed is increased. In higher-speed electric motors, efficiency is greatly improved if a very thin, non-metallic barrier can be utilized. The barrier thickness needs to be approximately 0.025-in. (≈0.6-mm) thick and can be made of a brittle material such as glass. The motors, however, designed for space applications are typically subject to high-vibration environments.

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Thermionic Power Cell To Harness Heat Energies for Geothermal Applications

Possible uses include geothermal exploration, automotive, and renewable energy applications. A unit thermionic power cell (TPC) concept has been developed that converts natural heat found in high-temperature environments (460 to 700 ºC) into electrical power for in situ instruments and electronics. Thermionic emission of electrons occurs when an emitter filament is heated to “white hot” temperatures (>1,000 ºC) allowing electrons to overcome the potential barrier and emit into the vacuum. These electrons are then collected by an anode, and transported to the external circuit for energy storage.

Posted in: Mechanics, Mechanical Components, Briefs, TSP

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Space Mirror Alignment System

An optical alignment mirror mechanism (AMM) has been developed with angular positioning accuracy of ±0.2 arcsec. This requires the mirror’s linear positioning actuators to have positioning resolutions of ±112 nm to enable the mirror to meet the angular tip/tilt accuracy requirement. Demonstrated capabilities are ±0.1 arc-sec angular mirror positioning accuracy, which translates into linear positioning resolutions at the actuator of ±50 nm.

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Spacesuit Soft Upper Torso Sizing Systems

This system has application in medical devices for immobilizing injured limbs or applying controlled pressure to areas of the body of a burn victim. The passive sizing system consists of a series of low-profile pulleys attached to the front and back of the shoulder bearings on a spacesuit soft upper torso (SUT), textile cord or stainless steel cable, and a modified commercial ratchet mechanism. The cord/cable is routed through the pulleys and attached to the ratchet mechanism mounted on the front of the spacesuit within reach of the suited subject. Upon actuating the ratchet mechanism, the shoulder bearing breadth is changed, providing variable upper torso sizing.

Posted in: Mechanics, Mechanical Components, Briefs

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