Special Coverage

Lightweight, Flexible Thermal Protection System for Fire Protection
High-Precision Electric Gate for Time-of-Flight Ion Mass Spectrometers
Polyimide Wire Insulation Repair System
Distributed Propulsion Concepts and Superparamagnetic Energy Harvesting Hummingbird Engine
Wet Active Chevron Nozzle for Controllable Jet Noise Reduction
Magnetic Relief Valve
Active Aircraft Pylon Noise Control System
Unmanned Aerial Systems Traffic Management

Thermal Cycle Qualification of Radiated Solar Arrays for 50 to 133 K Temperatures in Vacuum

A closed loop system needs no liquid helium. NASA’s Jet Propulsion Laboratory, Pasadena, California Solar arrays (radiated or non-radiated) and other technologies are candidate materials for projects in JPL. Some of the projects need to qualify these potential technologies to cryogenic extreme temperatures (from 133 to 50 K or lower). Those technologies need to survive for more than 120 thermal cycles in a thermal vacuum environment to meet three times mission life of the ECM project per JPL design principles. There is not any published thermal cycling qualification data for solar arrays in vacuum to those of cryogenic temperatures. Therefore, an experimental assessment study was undertaken on behalf of the JPL pre-project office for the proposed Europa Clipper mission.

Posted in: Briefs, TSP, Imaging, Photonics, Solar energy, Thermal management, Thermal testing


Downhole Regolith Interrogation with Helium-Assisted Drill and Laser Induced Breakdown Spectroscopy

Marshall Space Flight Center, Alabama It is of great interest to the scientific community to have the ability to analyze drilled boreholes in situ on the surfaces of the Moon and Mars. The goal of this work was to design and fabricate a Downhole Regolith Interrogation with Helium-assisted Drill and Laser Induced Breakdown Spectroscopy (LIBS) system (DIHeDRAL) targeted towards such applications. A DIHeDRAL instrument would provide synchronous exposure and analysis of volatiles using laser pulses, preserve borehole stratigraphy information, assess regolith mechanical properties through drilling telemetry, and analyze sensitive elemental composition.

Posted in: Briefs, Imaging, Photonics, Lasers, Spectroscopy, Soils, Drilling, Spacecraft


Large, High-Speed, Precision Optic Indexing Wheel

New wheel would enable more observational modes to be done in a given time. NASA’s Jet Propulsion Laboratory, Pasadena, California Optical indexing wheels, sometimes called “filter wheels,” are used to locate various optics or filters in a beam path to change the observational mode. Large wheels a half-meter in size or larger typically operate slowly, although the loss of a few seconds of time moving from one observation mode to another is not an issue. In certain rare applications, it is desirable to index between a large selection of optics at a faster rate. If the device is intended for space use, the power requirement becomes critical as well. Current indexing wheel designs typically use a central direct-drive motor to avoid the complication of gears, but these designs will draw too much power and work too slowly for certain applications. They also may require an ultrahigh bit encoder to achieve required positioning accuracy. Designers of such devices would readily admit that speed and power efficiency are both increased through the use of a gear reduction, but generally see the use of gears as problematic.

Posted in: Briefs, Imaging, Photonics, Wheels, Optics, Gears


Web-Based Search Service to Support Imaging Spectrometer Instrument Operations

An adaptive matched-filter approach compensates for the context and background characteristics of each scene. NASA’s Jet Propulsion Laboratory, Pasadena, California Imaging spectrometers yield rich and informative data products, but interpreting them demands time and expertise. There is a continual need for new algorithms and methods for rapid firstdraft analyses to assist analysts during instrument operations. Intelligent data analyses can summarize scenes to draft geologic maps, searching images to direct operator attention to key features. This validates data quality while facilitating rapid tactical decision-making to select follow-up targets. Ideally, these algorithms would operate in seconds, never grow bored, and be free from observation bias about the kinds of mineralogy that will be found.

Posted in: Briefs, TSP, Imaging, Photonics, Mathematical analysis, Internet, Spectroscopy, Data management


Hermetic Phototube Housing

Goddard Space Flight Center, Greenbelt, Maryland This innovation is a hermetically sealed case or very small chamber. A photomultiplier tube (PMT) is mounted inside the chamber. The circuit board is also installed inside the chamber with appropriate feedthroughs for signals. An adapter/floating mount called the phototube to light pipe system mount (PLPSM) allows the hermetic PMT housing to attach to the light guide.

Posted in: Briefs, TSP, Imaging, Photonics, Containers, Mountings


Design, Fabrication, and Test of WFIRST/AFTA GRISM Assembly

Goddard Space Flight Center, Greenbelt, Maryland This work originated with the Wide Field InfraRed Survey Telescope (WFIRST) slitless spectrometer design (GRISM assembly), which attempted to follow the Hubble Space Telescope (HST) method of employing a singleelement GRISM as a slitless spectroscope. However, WFIRST’s field of view (FOV) is ~100x of HST’s wide field camera, and the spectral resolution is ~5x higher with a relatively faster f/8 system. The design turned out to be extremely difficult using only one diffractive surface. Even with many freeform optical elements, and putting a grating on a toroid surface, the image performance was still not satisfactory.

Posted in: Briefs, TSP, Imaging, Photonics, Mirrors, Optics, Spectroscopy, Product development


Spinal Ultrasound Just-in-Time Training Tool

This software facilitates ultrasound imaging of the cervical and lumbar spine by crewmembers in-flight. Lyndon B. Johnson Space Center, Houston, Texas Back pain and injury are recognized risks that can affect the well-being and performance of crewmembers during missions, as well as their long-term health. Spine elongation is a documented effect of microgravity, back pain is a common occurrence in early flight, and the post-flight incidence of spinal injury is higher than the population average. These observations suggest that spinal unloading results in a transition to a new set point for the spine, and causes discomfort and an increased risk of injury.

Posted in: Briefs, TSP, Imaging, Photonics, Personnel, Injury causation, Spacecraft


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