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Technology for a Comet Sample Return Mission Version 2

Harpoon-based sample collectors with rectangular cross-sections are regarded as the best candidates. Goddard Space Flight Center, Greenbelt, Maryland A standoff sample collection system would be capable of quickly obtaining a sample from environments as varied as comets, asteroids, and permanently shadowed craters on the Moon from vehicles ranging from traditional planetary spacecraft to platforms such as hovering rotorcraft or balloons at Mars, Venus, or Titan. The depth of penetration for this harpoon-based hollow collector design was experimentally determined to be proportional to the momentum of the penetrator, in agreement with earlier work on the penetration of solid projectiles. A release mechanism for the internal, removable sample cartridge was tested, as was an automatic closure system for the sample canister and tether recovery approaches.

Posted in: Mechanical Components, Briefs

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Nitrous Oxide Ethane-Ethylene Engine

Marshall Space Flight Center, Alabama The Nitrous Oxide Ethylene-Ethane (NEE) engine uses nitrous oxide as an autogenously pressurizing oxidizer, and a mixture of ethane and ethylene is used in the same manner as fuel. Initially, the ethane and ethylene mixture has the same vapor pressure as the nitrous oxide. By using the autogenous pressurization capabilities of these propellants, instead of an additional pressurization system, greater system simplicity and reliability can be attained. The NEE can obtain a specific impulse of 320 s, making it the highest-performing, non-toxic, storable bipropellant rocket propulsion system in existence at the time of this reporting.

Posted in: Mechanical Components, Briefs

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Method for Improved Gun-Drilled Cold Plate Fabrication and Inspection

Lyndon B. Johnson Space Center, Houston, Texas A method was developed for obtaining proper fluid distribution through parallel gun-drilled passages and for being able to inspect the actual drilled passages to guarantee that the designed minimum wall thickness is not violated. This invention uses one feature that addresses both issues mentioned. By machining a “trough” in the center of the cold plate that intersects the gun-drilled passages where they meet in the center, the area where the two drilled passages intersect is removed and any mismatch is eliminated. This allows access for direct inspection of the drill wander. An integral cap, which incorporates orifice features to address the fluid distribution, is then inserted into this trough. This method can also work in a two-layer cold plate where every other fluid passage is for the alternating fluid layer.

Posted in: Mechanical Components, Briefs

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Powder Handling Device for Analytical Instruments

Powder is handled as a fluid via equipment that requires few or no moving parts. Ames Research Center, Moffett Field, California A new technology provides for automated sample handling and movement of coarse-grained powder or other solid materials to enable analysis by a robotic or totally automated computer system. Currently, many analytical instruments require a powder sample to control the shape and/or volume of the specimen, to increase the surface area of the specimen, to increase the statistical representation of a specimen when samples are not homogeneous with regard to the characterized property, and/or to increase the statistical representation of the specimen spatial orientation when the properties being characterized are not equivalent in different viewing directions. Grinding the material down to an ideal grain size is sometimes impossible, and conditioning the sample for analysis is often time-consuming and labor-intensive. In the new approach, the powder is handled as a fluid, using mechanical vibrations in conjunction with a driving force (gravity or gas flow), and requiring few or no moving parts.

Posted in: Mechanical Components, Briefs

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Improved Light Injection and Detection Methods for fNIRS Headgear for Use in Avionics and Astronautics

The benefits of the innovation allow the technique to move out of the controlled laboratory and into clinical and operational environments. John H. Glenn Research Center, Cleveland, Ohio Measuring hemoglobin concentration changes in the brain with functional near infrared spectroscopy (fNIRS) is a promising technique for monitoring cognitive state to optimize human performance during both aviation and space operations. The detection and prevention of performance decrement is also relevant to safety-critical operational tasks such as monitoring for air traffic control, performing surgery, and driving. Advances in optical instrumentation for fNIRS have been conceptualized and integrated into several new headgear prototypes designed for use by operators in the real world.

Posted in: Physical Sciences, Briefs

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How to Maximize Temperature Measurement Accuracy

Thermocouples are the most versatile and widely used devices for temperature measurements. Most test engineers are aware of the measurement errors caused by thermocouples but not always about the errors caused by the measurement system itself. This technical note will focus on the lesser known and important aspect called "Self-Calibration" and how it can be used to overcome errors in temperature measurement.

Posted in: Test & Measurement, White Papers

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A High-Cross-Polarization-Isolation, Multi-Frequency Antenna for Cloud and Precipitation Research

Goddard Space Flight Center, Greenbelt, Maryland The Global Precipitation Mission (GPM) has an immediate need for a matched-beam Ku-band/Ka-band antenna system that can be used as a component of a ground validation radar. Retrieval techniques based on both polarization and differential absorption at the two wavelengths can be used to provide additional insight into precipitation type and particle size distribution over a 10- to 40-km spatial domain. These measurements can then be compared with long range radar, such as the WSR-88D, and in situ sensors to provide a comprehensive dataset for evaluating and improving satellite-based precipitation estimates.

Posted in: Physical Sciences, Briefs

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