Topic

A method was developed to create high-fidelity lunar dust simulants that better match the unique properties of lunar dust than the existing simulants. The new dust simulant is designed to more closely approximate the size, morphology, composition, and other important properties of lunar dust...

Future NASA missions aimed at exploring Mars, the Moon, and the outer planets require rechargeable batteries that can operate over a wide temperature range (–60 to +60 °C) to satisfy the requirements of various applications. In addition, many of these applications...

A novel, high-efficiency gas particulate filter has precise particle size screening, low pressure drop, and a simple and fast regeneration process. The regeneration process, which requires minimal material and energy consumption, can be completely automated, and the filtration performance can be...

A “simplified shear solution” method approximates the through-thickness shear stress distribution within a composite laminate based on an extension of laminated beam theory. The method does not consider the solution of a particular boundary value problem; rather, it requires only knowledge of...

A new solar-cell structure utilizes a single, ultra-wide well of either gallium arsenide (GaAs) or indium-galliumphosphide (InGaP) in the depletion region of a wide bandgap matrix, instead of the usual multiple quantum well layers. These InGaP barrier layers are effective at reducing diode dark current, and...

A major goal of the Supersonics Project under NASA’s Fundamental Aeronautics program is sonic boom reduction of supersonic aircraft. An important part of this effort is development and validation of sonic boom prediction tools used in aircraft design. NASA Dryden’s...

A compact, high-resolution angle measurement instrument has been developed that is based on a heterodyne interferometer. The commonpath heterodyne interferometer metrology is used to measure displacements of a reflective target surface. In the interferometer setup, an optical mask is used to sample the...

A proposed method of automated, precise alignment of a ground-based astronomical telescope would eliminate the need for initial manual alignment. The method, based on automated identification of known stars and other celestial objects in the telescope field of view, would also eliminate...

Optical combs generated by a monolithic resonator with Kerr-medium can be used in a number of applications, including orbital clocks and frequency standards of extremely high accuracy, such as astronomy, molecular spectroscopy, and the like. The main difficulty of this approach...

A large-format hybridized AlGaN photodiode array with an adjustable bandwidth features stray-light control, ultra-low dark-current noise to reduce cooling requirements, and much higher radiation tolerance than previous technologies. This technology reduces the size, mass, power, and cost of...

Mathematically sound techniques are used to view a knowledge-based system (KBS) as a set of processes executing in parallel and being enabled in response to specific rules being fired. The set of processes can be manipulated, examined, analyzed, and used in a...

An emerging methodology of organizing systems-engineering plans is based on a concept of core and off-core processes or activities. This concept has emerged as a result of recognition of a risk in the traditional representation of systems-engineering plans by a Vee model alone, according to which a...

In support of investigations of mishaps like the crash of the space shuttle Columbia, a process based on digital reconstruction from recovered components has been developed. The process is expected to reduce the need for physical reconstruction from recovered parts, reduce the time and cost...

A new approach to signal prediction and prognostic assessment of spacecraft health resolves an inherent difficulty in fusing sensor data with simulated data. This technique builds upon previous work that demonstrated the importance of physics-based transient models to accurate prediction of signal...

In 2001, NASA engineer Michael Ewert developed and patented a unique solar-powered vapor-compression refrigeration system that operates without batteries or external power of any kind. The system, which is powered by a...

This week's Question of the Week focuses on the redesign of some Internet communication services. Law enforcement officials want Congress to require all services that enable communications — including encrypted e-mail...