Special Coverage

Soft Robot “Walks” on Any Terrain
Defense Advanced Research Projects Agency
Using Microwaves to Produce High-Quality Graphene
Transducer-Actuator Systems for On-Machine Measurements and Automatic Part Alignment
Wide-Area Surveillance Using HD LWIR Uncooled Sensors
Heavy Lift Wing in Ground (WIG) Cargo Flying Boat
Technique Provides Security for Multi-Robot Systems
Bringing New Vision to Laser Material Processing Systems
NASA Tests Lasers’ Ability to Transmit Data from Space
Converting from Hydraulic Cylinders to Electric Actuators
Automating Optimization and Design Tasks Across Disciplines

Vacuum Pumping Station

A proposed valve unit called a "vacuum pumping station" would be incorporated into a plumbing system that supplies a vacuum for vacuum insulated cryogenic equipment. The vacuum pumping station is intended to perform functions now performed by, and to be a simpler and more reliable alternative to, an assembly of components that include a vacuum-pump-out valve and a separate vacuum-isolation valve (with a separate actuator) used to monitor vacuum levels. The present assembly includes a leak-prone threaded connection between the pump-out and isolation valve, and leaks can also occur at other locations. The vacuum pumping station would include a vacuum-pump-out port, a thermocouple port, a thermocouple-isolation valve, a pressure-relief valve, a pressure-relief port, and a single mechanism for actuating the pump-out, isolation, and pressure-relief functions of the valve. The number of joints where leaks could develop would be only half that of the present assembly.

Posted in: Briefs, Mechanical Components, Mechanics, Pumps, Valves

Digital Preassembly Process

Assembly of major elements of large structures is simulated in a CAD environment.

Because the International Space Station is being assembled in orbit, there was a need to verify in advance that it could, indeed, be assembled there and that the various assembled parts would function as intended. A digital preassembly process was devised to satisfy this need for verification, without having to perform assembly on Earth. The process enables designers to simulate the assembly of major elements of large structures by use of a computer-aided design (CAD) system. The process could also be applied in any type of manufacturing and in many types of construction.

Posted in: Briefs, Manufacturing & Prototyping, CAD / CAM / CAE, CAD, CAM, and CAE, Computer simulation, Assembling, Spacecraft

Numerical Index for Quantifying Aircraft Icing Hazards

This index would offer several advantages over the present four-level index.

A new method for assessing and communicating aviation in-flight icing hazards has been proposed. This methodology creates a simple numerical index for quantifying hazard severity. The index is traceable to flight-level meteorology and aircraft-specific, icing-induced reductions in aircraft performance. It also provides a connection to a statistical data base of icing meteorology. This system will clarify the terminology used to describe the degree of danger posed by specific meteorological conditions. The relationship between hazard severity and meteorology is related by measured ice accumulation rates observed on a standard airfoil under prescribed conditions. This system has greater fidelity than the existing system and is applicable to all types of air vehicles.

Posted in: Briefs, TSP, Physical Sciences, Icing and ice detection, Aircraft

DNS of Mixing of Supercritical Heptane and Nitrogen

A report discusses direct numerical simulations (DNS) of a developing mixing layer between nitrogen and heptane initially at different temperatures and initially flowing at different velocities under supercritical conditions. The usual conservation equations for a binary fluid, along with the Peng-Robinson equation of state for the heptane/nitrogen mixture, were solved numerically and the solutions analyzed. Departures from perfect-gas and ideal-mixture conditions were quantified by compression factors and mass-diffusion factors, both of which exhibited decreases from unity.

Posted in: Briefs, TSP, Physical Sciences, Computer simulation, Mathematical models, Gases

Gas Generator for Inflating Structures in Outer Space

A report proposes a system that would supply gas for inflating one or more inflatable structure(s) in outer space. The system would include a small tank of helium for initial inflation, plus a catalytic hydrazine gas generator that would supply makeup gas over the long term. After initial inflation, when makeup gas was needed, liquid hydrazine from a tank would be made to pass through a catalytic bed, where it would become decomposed into a mixture of N2, H2, and a small amount of NH3. This gaseous mixture would constitute the makeup gas and would be stored in the tank that previously contained the helium. The makeup gas would be released from the tank to the structure(s) as needed. In comparison with an inflation system based only on compressed gas stored in tanks, the proposed inflation system would offer the advantage of lower mass: About 25 percent of the masses of representative previously contemplated large inflatable outer-space structures would have been contained in their inflation systems. In contrast, the mass of the proposed inflation system has been estimated to be only about 13 percent of the total mass of a representative structure.

Posted in: Briefs, TSP, Mechanical Components, Mechanics, Gases, Spacecraft

Thermal Insulation Would Use CO2 in the Martian Environment

A report describes the development of a lightweight thermal insulation system for Martian surface applications. The ambient Martian atmosphere, which is predominantly carbon dioxide at a pressure of 10 torr, is used as the insulation medium with a modest multiple radiation shield enclosure. The carbon dioxide has a thermal conductivity that is very close to traditional insulation, and the carbon dioxide is naturally available on the Martian surface. Preformed Mylar spacers that are affixed to the hardware create the necessary standoff distance from the enclosure.

Posted in: Briefs, TSP, Materials, Carbon dioxide, Insulation

Martian Landing Balls

A report describes Martian landing balls, which are under development for use in delivering scientific payloads to Mars. Martian landing balls are related to other soft-landing devices that resemble beach balls and that have been described in several previous NASA Tech Briefs articles. They are also related to the Zorb (or equivalent) — a commercial recreational device that looks like a large, transparent beach-ball/tire hybrid with a central volume that is open to the atmosphere and that accommodates a human rider. In a Mar-tian landing ball, the central volume contains a rigid cylinder that carries the payload. The cylinder is surrounded (except for small openings) by an approximately spherical airbag. In the intended use, Martian landing balls would be dropped from slowly descending solar-heated balloons. It has been estimated that a Martian landing ball with a mass of 2 kg could deliver a 10-kg payload with a landing acceleration of less than 50× normal Earth gravitation (less than about 490 m/s2). Once on the Martian surface, the airbag could be deflated; alternatively, the airbag could be kept inflated to take advantage of the wind to blow the payload to a desired location.

Posted in: Briefs, TSP, Mechanical Components, Mechanics, Entry, descent, and landing

Fractal-Based Encryption

Encryption methods based upon nonprobabilistic nondeterminism show promise in the optical age.

In 1987 a discovery led to the formal proof that it is possible to use chaotic functions to arrive at a nonprobabilistic and nondeterministic method normal context of the operation of this system, and by using a virtual operational environment, the investigators are manipulating data in eight dimensions, which require a sixty-four discrete coordinate system, using eight nominative octets. Each octet is further addressed using the characters 0 through 9, and lower- or upper-case letters from A to Z. These provide the ability to address using normal ASCII characters. This format was chosen to ensure backward and forward compatibility with external third-party-written software.

Posted in: Briefs, ptb catchall, Tech Briefs, Photonics, Mathematical analysis

Coherent Phase Line Enhancer: a Method of Spectral Analysis

This method enables detection of weak signals that would otherwise be masked by noise.

The term "coherent phase line enhancer" (CPLE) refers to a dual-transform method of spectral analysis that enhances the detection of periodic and quasi-periodic signals buried in wide-band noise. The CPLE is particularly useful for increasing the signal-to-noise ratios of spectral peaks ("lines") that represent periodic and quasi-periodic components of measurements of vibration, dynamic strain, and/or dynamic pressure in a turbine or other rotating machine. The purpose of such measurements, spectral analysis, and enhancement of spectral peaks is to assess machine performance and identify spectral signatures of bearing or gear-train defects.

Posted in: Briefs, Information Sciences, Failure analysis, Imaging, Imaging and visualization, Imaging, Imaging and visualization, Noise, Noise, Bearings, Gears

Software for Secure Distribution of Data

Many users at remote locations can work on the same set of data.

MECS is a computer program for the automated, secure, rapid, and efficient transfer of data between a central source and users at multiple distant locations. "MECS" signifies "Multi-mission Encrypted Communication System." MECS enables many users to collaborate securely on a shared plan or set of data.

Posted in: Briefs, TSP, Information Sciences, Computer software / hardware, Computer software and hardware, Cyber security, Data exchange, Computer software / hardware, Computer software and hardware, Cyber security, Data exchange

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