Tech Briefs

Homography Warp Image FPGA Implementation

NASA’s Jet Propulsion Laboratory, Pasadena, California A landing system for Mars matches features seen in descent imagery against a map constructed from orbital imagery. The spacecraft attitude and altitude are known, but lateral position is known only poorly. From attitude and altitude, one can generate a mapping (homography) that allows the descent image to be warped into the orthonormal viewpoint of the map. The homography maps any pixel in the map image to the corresponding pixel in the descent image.

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Hybrid DC Circuit Breaker Based on Cryogenic Technique

This hybrid solution combines mechanical and solid-state technology. John H. Glenn Research Center, Cleveland, Ohio DC protection systems such as circuit breakers play a key enabling role for the DC power system in applications such as aviation, the power grid, and the like. Conventional electromagnetic circuit breakers are a mature technology. However, the large size and high response time make it unsuitable for an electrical system in aviation that requires fast response time. Compared with a mechanical circuit breaker, the solid-state circuit breaker based on high-power semiconductors can provide a fast response time to make the fault current fully controlled. The on resistance of the semiconductors creates high conduction loss, which leads to low efficiency. Therefore, a hybrid solution that combines both mechanical and solid-state technology is desired.

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Modular Propulsion and Deployment Electronics System

The new approach is flexible enough to quickly accommodate design changes. Goddard Space Flight Center, Greenbelt, Maryland The Lunar Reconnaissance Orbiter (LRO) required an innovative and modular approach to the design and development of the electronics needed to control the propulsion and deployment components, as well as the electronics necessary to support safety inhibits for personnel and range requirements. Since these electronics would be designed in parallel with the systems they would interface with, they would need to be flexible enough to quickly accommodate ongoing design changes.

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All-Organic Electroactive Device Fabricated with Single- Wall Carbon Nanotube Film Electrode

These devices have applications as electromechanical sensors, sonar, medical and optical devices, artificial muscles, and noise control. Langley Research Center, Hampton, Virginia A novel, all-organic electroactive device system has been fabricated with a single-wall carbon nanotube (SWCNT) film used as an alternative electrode. This system was fabricated with LaRC-Electro Active Polymer (LaRC-EAP) active layer and the SWCNT films by pressing at 600, 3,000, and 6,000 psi (≈4.1, 20.7, and 41.4 MPa, respectively). Silicone elastomer plates (3-mm thick) were used on the press plate surfaces for better contact adhesion between the SWCNT film and the actuating layer. This polymeric electroactive device layered with the SWCNT-FE (SWCNT-Film Electrode) can serve as an actuator. The density (or modulus) of the SWCNT-FE can be controlled by adjusting the fabrication pressure. It is anticipated that less dense SWCNT-FE can provide less constrain displacement of the polymeric actuating layer by matching the modulus.

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Purifying Hydrogen for a Life Support Process

An advanced hydrogen purification technology is proposed to purify hydrogen of acetylene, carbon monoxide, and other gases to enable utilization of the hydrogen for oxygen recovery. Marshall Space Flight Center, Alabama NASA’s endeavor to further enable long-duration manned space exploration requires further closure of the oxygen loop of the life support system that is currently realized aboard the International Space Station. Currently, oxygen is recovered from crew-generated carbon dioxide via the use of a Sabatier carbon dioxide reduction system coupled with water electrolysis. Water is electrolyzed to form oxygen for crew consumption, as well as hydrogen. The hydrogen is reacted with carbon dioxide, forming water and waste methane gas. Since hydrogen is lost from the desired closed-loop system in the form of methane, there is insufficient hydrogen available to fully react all of the carbon dioxide, resulting in a net loss of oxygen from the loop. In order to further close the oxygen loop, NASA has been developing an advanced plasma pyrolysis technology that further reduces the waste methane to higher hydrocarbons in order to better utilize the hydrogen for oxygen recovery.

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Low-Pressure Casting of Bulk Metallic Glasses for Gears and Other Applications

Applications include the automotive, aeronautics, aerospace, robotics, commercial, and military/defense industries. NASA’s Jet Propulsion Laboratory, Pasadena, California With the correct selection of composition, some bulk metallic glasses (BMGs) have been demonstrated that have excellent combinations of hardness, fracture toughness, and wear resistance so that their use in gears and gearboxes is a potentially commercially viable application. For BMGs to be used as a low-cost alternative to steel gears, rapid fabrication strategies are needed to cast the BMGs into net-shaped gears that require little or no post-casting machining prior to use. Die casting, suction casting, and other cold-mold casting techniques have been widely demonstrated for BMGs in the past, but the unique nature of gears precludes traditional techniques from being used in an optimal way.

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Lunar Materials Handling System

Lyndon B. Johnson Space Center, Houston, Texas A method was developed for transfer of lunar soil into and out of process equipment. The Lunar Materials Handling System (LMHS) conveys solids to a process vessel, provides a gas-tight seal, prevents seal contamination, and minimizes wear from abrasive particles. The LMHS increases equipment life and minimizes process losses, thereby increasing overall in-situ resource utilization (ISRU) leverage. The LMHS is based on a seal arrangement by which lunar or Mars regolith can be repeatedly introduced into, and removed from, reaction chambers operating under a wide range of conditions. An integrated LMHS was demonstrated during operation in a one-cubic-meter vacuum chamber using hydrogen reduction as an ISRU process demonstration platform.

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