Physical Sciences

A Continuous-Flow, Microfluidic, Microwave-Assisted Chemical Reactor

The reactor uses a directed 60-GHz source, which may require far less power to observe the same reactivity profiles. NASA’s Jet Propulsion Laboratory, Pasadena, California In industrial synthetic chemistry laboratories, reactions are generally carried out using batch-mode methodologies, stepwise reactions, and purifications to generate a final product. Each step has an associated yield of both the reaction itself and of the final purification that is largely dependent on the procedure being used, and the scientist carrying out the procedure. Continuous-flow reactors are one way of streamlining the process. Furthermore, microwave-enhanced, or microwave-assisted, chemistry has been demonstrated to aid in many of these areas; however, scaling has been a traditional problem with this technique.

Posted in: Physical Sciences, Test & Measurement, RF & Microwave Electronics, Articles, Briefs, TSP, Instrumentation

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Monolithic Dual Telescope for Compact Biaxial Lidar

Goddard Space Flight Center, Greenbelt, Maryland A document discusses the Ultra Compact Cloud Physics Lidar, a biaxial lidar with a narrow receiver field of view. It requires tight optical alignment between the transmitter and receiver paths while flying on various aircraft over various temperatures and in the presence of vibration. To achieve optical crossover as close to the lidar as possible, the transmit and receive telescopes must be built very closely to each other.

Posted in: Tech Briefs, Physical Sciences, Photonics, Articles, Briefs, TSP

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Ultra-Low-Maintenance Portable Ocean Power Station

These fuel cell systems can be used for remote power generation, transportation applications, or in offshore wells. NASA’s Jet Propulsion Laboratory, Pasadena, California The goals of this research are to develop a relatively inexpensive, compact, and modular power package for deep offshore oil drilling or other undersea applications that provides 2 to 5 MW electricity, minimal maintenance, and at least 30 years of life.

Posted in: Physical Sciences, Briefs, TSP

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Alternating Magnetic Field Forces for Satellite Formation Flying

John F. Kennedy Space Center, Florida Orbiting a large number of satellites in fixed formations will be critical to many future space missions, especially large-scale interferometers, telescopes, antennas, and gravity wave detectors. Consequently, extensive research has been devoted over the last 20 years to formation flying architectures, concentrating not only on the mission objective, but also on the technologies required to achieve a stable satellite formation. Several proposals have been suggested for determining the location of the satellites, but the more difficult problem is developing a system that can hold the satellites at those desired locations and orientations. The two most common solutions are to use microthrusters, though these require propellant and will eventually be depleted, or to choose orbital patterns that minimize relative perturbations, but for highly precise positioning, this is not adequate. Neither of these approaches solves the problem for long-duration missions such as a multi-element telescope where the mirrors must be located and oriented to a tolerance less than an optical wavelength.

Posted in: Physical Sciences, Briefs, TSP

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Multiplexer for Multiple Sensors in a Vacuum Chamber

The multiplexer reduces the number of required feedthroughs and ports. John F. Kennedy Space Center, Florida Vacuum chamber testing at large facilities can require hundreds of instruments, necessitating even more feedthroughs. The number of instruments and sensors that can be fed into a vacuum chamber is limited by the number of feedthrough ports dedicated to instrumentation. Thus high-pin-count, mil-spec-style feedthroughs have been developed, but these are all custom-made and also expensive to make and replace. The high-pin-count feedthroughs also make it much harder to troubleshoot individual wires in case of a problem. By using a multiplexer within the vacuum chamber, the number of wires required per instrument can be reduced to much less than one. The multiplication of wires from within a vacuum chamber allows a drastic increase in sensor and instrumentation channel count, while using the same number of sensor ports and feedthroughs within an existing vacuum system.

Posted in: Physical Sciences, Sensors, Briefs, TSP

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Analog Ceramic Isolated Voltage Sensor

John H. Glenn Research Center, Cleveland, Ohio Galvanic isolated monitoring of voltages for launch vehicle, missiles, and space-deployed systems can be very challenging. Radiation exposure makes use of optics-based sensors difficult, as they can latch-up and become corrupted by the radiation environment; such devices can moreover be thermally challenged. Magnetic transformer-based methods of isolated voltage measurement require shielding to prevent stray magnetic interference from degrading or corrupting the readings; moreover, magnetic-based solutions are unable to measure voltages down to DC levels.

Posted in: Physical Sciences, Sensors, Briefs, TSP

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Flexible and Erectable Magnetic Field Response Sensors

Langley Research Center, Hampton, Virginia The means to make a flexible and/or erectable magnetic field response sensor, a geometrically fixed capacitor mounting frame, a wireless dipstick, and an elastically flexible capacitor support have been developed. Either the capacitor mounting frame or the flexible, erectable magnetic field response sensor can be developed to take measurements in hazardous conditions, or in containers with environmentally harmful contents, such as a gasoline storage tank.

Posted in: Physical Sciences, Sensors, Briefs, TSP

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