Mechanical & Fluid Systems

Powdered Copper Cryogenic Heat Exchanger

This technology provides a high level of thermal performance while dramatically simplifying the chore of determining safety factors.

John F. Kennedy Space Center, Florida

This work involved designing a liquid nitrogen cold-plate heat exchanger with a high thermal mass using code-standard, high-pressure tubing. High thermal mass requires a substantial amount of material, so heat exchangers of this type are usually fabricated from a solid piece of metal (such as copper) with fluid paths machined into the component. However, standard tubing was desired for the fluid path due to its pressure rating and predictability. The key problem was how to embed copper tubing into a larger mass while maintaining good heat transfer properties.

Posted in: Briefs, TSP, Mechanical Components, Thermal management, Copper
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Diminutive Assembly for Nanosatellite deploYables (DANY) Miniature Release Mechanism

New deployment mechanism offers improved reliability with minimum space and weight penalty.

Goddard Space Flight Center, Greenbelt, Maryland

CubeSat appendices such as solar panels and antennas often need to be constrained by a release mechanism during launch. These appendices are then deployed once the desired orbit is reached. The usual constraint method used is a combination of an unpredictable/ unreliable fishing line and burning wire. If a proper release mechanism is used, it utilizes a considerable amount of CubeSat internal space, making the internal packaging of the satellite more difficult. These two methods have adverse effects on CubeSat performance.

Posted in: Briefs, TSP, Mechanical Components, Satellites
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Quantitative Real-Time Flow Visualization Technique

This technique enables real-time monitoring of pressure fields and flow measurement.

John H. Glenn Research Center, Cleveland, Ohio

There is a need for experimental techniques that have low cost and rapid turnaround. It is also necessary to obtain quantitative information from such a method. Previous methods are either lacking in quantitative information such as dye or smoke injection, or require considerable set-up and cost such as PIV (particle image velocimetry). A method was developed for visualizing the pressure contours for a turbine cascade in real time to enable rapid evaluation of new concepts. A method for quantitative 3D flow visualization also was developed.

Posted in: Briefs, TSP, Mechanical Components, Computational fluid dynamics, Imaging and visualization
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Thin-Film Evaporative Cooling for Side-Pumped Lasers

This technology has applications in advanced lidar systems for weather satellites; in welding, cutting, and marking; and in test and measurement.

Langley Research Center, Hampton, Virginia

A highly efficient way to cool solid-state crystal lasers was developed. This thin-film evaporative cooling technique offers higher optical efficiencies and monochromatic quality than traditional conductive cooling techniques. Developed for use in side-pumped 2.0- micron laser systems used in light detection and ranging (lidar) instruments, the thin-film cooling design concept also has broad utility for diode-pumped solid-state laser (DPSSL) systems, especially those with high heat flux or challenging packaging requirements.

Posted in: Briefs, TSP, Mechanical Components, Optics, Thermal management, Cooling
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MEMS Micro-Translation Stage with Large Linear Travel Capability

Marshall Space Flight Center, Alabama

A MEMS (microelectromechanical systems) micro-translation stage (MTS) with large linear travel capability was developed that uses capacitive electrostatic forces created by stators arranged linearly on both sides of a channel, and matching rotors on a moveable shuttle for precise movement of the shuttle. The device, which is essentially a linear motor built from silicon base with microfabrication techniques, will be able to rapidly translate across large distances using only three-phase power. The moveable shuttle can be as small as 100 mm and can house a variety of elements including lenses and mirrors. The shuttle can be tailored to travel distances as small as 10 mm and as large as 300 mm, with as little as 10 mm between adjacent shuttle stops.

Posted in: Briefs, Mechanical Components, Optics
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Planar and Non-Planar Multi-Bifurcating Stacked Radial Diffusing Valve Cages

This technology is applicable in systems and devices where high-pressure-differential valves are used.

A valve cage consists of a stackable planar structure design with paths that are azimuthally cut out and connected radially. The pattern causes the flow to move azimuthally and impinge on each other when moving to the next path, thereby reducing the fluid momentum and energy that reduces the erosion capability. The maze-like structure is easy to machine with standard machining techniques.

Posted in: Briefs, TSP, Mechanical Components, Mechanics, Parts
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MEMS Gyroscope with Dual Interferometric Sense Elements

This sensing technique enables the use of a large proof mass with very low thermomechanical noise.

John F. Kennedy Space Center, Florida

High-performance inertial sensors, such as ring laser gyroscopes or fiber optic gyroscopes, have sufficient performance to enable “dead reckoning” navigation for adequate periods of time. Smaller microelectromechanical system (MEMS) inertial sensors, such as MEMS gyroscopes and MEMS accelerometers, typically have relevant performance characteristics that are 10 or 100 times worse than high-performance inertial sensors. As a result, these small MEMS inertial sensors must be aided by a global positioning system (GPS) if they are to be used for navigation.

Posted in: Briefs, TSP, MEMs, Sensors, Sensors and actuators
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ACS Anchor Guide Stud and Caddy

Goddard Space Flight Center, Greenbelt, Maryland

An alignment guide and a mounting interface for two of the repair tools on orbit during the Hubble Space Telescope Servicing Mission 4 (see http://asd.gsfc.nasa.gov/archive/hubble/missions/sm4.html) were developed. This design can be installed in a timely manner, and was specifically developed for a worksite with minimal access and minimal visual line-of-sight to the worksite. In addition, this technology was specifically designed for on-orbit work by astronauts, and can be used for any space-related work where an alignment aid or mounting interface is required.

Posted in: Briefs, TSP, Aerospace, Fastening, Joining & Assembly, Mechanical Components, Tools and equipment
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Next-Generation, Lightweight Hard Upper Torso/Hatch Assembly

Lyndon B. Johnson Space Center, Houston, Texas

The current MK-III carbon-graphite/epoxy Hard Upper Torso (HUT)/hatch assembly represented an 8.3 psi (≈57 kPa) technology demonstrator model of a zero pre-breathe suit. In this configuration, the MK-III suit weighed about 120 lb (≈54 kg). Since future lunar/planetary suits will need to operate under the influence of gravity, as well as operate at 4.3 psi (≈30 kPa), the weight of the suit had to be reduced to a minimum of 79 lb (≈36 kg) with the incorporation of lightweight structural materials and slight HUT/hatch assembly geometric redesign.

Posted in: Briefs, TSP, Aerospace, Mechanical Components, Lightweight materials, Protective clothing, Lightweighting
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Elastic Deployable Composite Tubular Roll-Out Boom

Goddard Space Flight Center, Greenbelt, Maryland

The objective of this work was to develop an innovative deployable boom/structure technology that is ultra-lightweight (<30-grams/meter potential), and has extremely compact stowage volume (>100:1 compaction ratio), broad scalability (no size limits envisioned), high deployed frequency, high deployed strength, good thermal/dimensional stability, reliable/immediate and repeatable controlled deployment, high stiffness maintained during the entire deployment sequence, affordability (simple, easily produced tubular structure, very low parts count, and proven tube manufacture provides low cost and rapid assembly), space environmental survivability, and broad mission applicability.

Posted in: Briefs, TSP, Aerospace, Mechanical Components, Composite materials, Lightweighting
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