Physical Sciences

Spacecraft Line-of- Sight Stabilization Using LWIR Earth Signature

Applications could include remote science and planetary science missions, Earth surveillance and reconnaissance, and deep space optical communication.

Until the time of this reporting, when a space vehicle required a reference signal for inertial pointing, the choices were a signal beacon from an Earth location, the Earth radiance in the visible spectrum, or a star tracker. However, limitations can arise from using these techniques. For example, the signal beacon suffers from limited signal power (either in RF or optical) and will constrain the application to limited ranges, errors due to stray-light and centroiding limit the accuracy of a star tracker, and the spatial/temporal variability of the Earth’s albedo and its illumination by the Sun introduces limitations when used in the visible or near infrared light.

Posted in: Briefs, Physical Sciences, Spacecraft guidance

Transportable Instrumentation Package for In-Vehicle On-Road Data Acquisition

This portable data acquisition system is a viable alternative to first developing a fully instrumented test vehicle.

The study of driver behavior can provide a wealth of information that can be useful in the design of automobiles including active safety features and functions. There may be differences in driver behavior, as reflected in driver state, and these differences may be confounded by a driver’s condition. Much can be learned from studies that look at driver state and condition to answer questions such as how vehicle features and functionality could be designed to complement the driver’s capabilities and limitations in the vehicle. Also, a better understanding could be gained to determine how, or if at all, a safety feature’s characteristics should be modified to accommodate a driver’s condition.

Posted in: Briefs, Physical Sciences, Data Acquisition, Human factors, Data acquisition, Data acquisition (obsolete), Test equipment and instrumentation

Variable Camber Aerodynamic Control Surfaces and Active Wing Shaping Control

Concepts are examined to reduce aerodynamic drag and decrease fuel consumption.

A new concept of aircraft aerodynamic control surfaces has been developed in connection with another new concept of active wing shaping control for reducing aircraft drag that will result in less fuel burn. The first concept is referred to as a variable camber continuous trailing edge flap or, alternatively, a variable camber continuous leading edge slat. The variable camber trailing edge flap (or leading edge slat) comprises multiple chord-wise segments (three or more) to form a cambered flap surface, and multiple span-wise segments to form a continuous trailing edge (or leading edge) curve with no gaps that could be prescribed by a mathematical function or the equivalent with boundary conditions enforced at the end points to minimize tip vorticities. Aerodynamic simulations have shown that this type of flap can reduce aerodynamic drag substantially as compared to a conventional flap. A new active wing-shaping control concept is proposed in connection with the presently disclosed variable camber continuous trailing edge flap (or leading edge slat). The active wing-shaping control is designed to change a wing shape in-flight in order to achieve a desired optimal wing shape for optimal drag reduction.

Posted in: Briefs, Physical Sciences, Wings, Aerodynamics, Aircraft

NanoRacks-Scale MEMS Gas Chromatograph System

This is a compact, simple, cost-effective system.

In order to study atmospheric or evolved gases, it is highly advantageous for an instrument (e.g. mass spectrometer (MS), thermal conductivity detector (TCD)) to simplify the gas stream with a front-end gas chromatograph (GC). When used for planetary missions, highperformance GCs have to satisfy the additional challenging requirements of surviving high inertial loads with low mass, power, and volume in order to be included in Ventures-, Discovery- and New Frontiers-class missions in today’s budget-constrained reality.

Posted in: Briefs, Physical Sciences, Gases, Test equipment and instrumentation

Simulation of Charge Carrier Mobility in Conducting Polymers

Electric conduction in polymers is one of the key elements in avoiding catastrophic internal electrostatic discharge in dielectrics during space missions. This software package enables the simulation of carrier mobility for any given site concentration, which is a material design parameter that can be varied in experimental studies. The software computes the charge mobility for a disordered network of carrier sites. The mobility is obtained by computing the average drift velocity for an applied electric field. The mobility is given by the ratio of the drift velocity to the electric field.

Posted in: Briefs, Physical Sciences, Software, Computer simulation, Conductivity, Polymers

Technique for Finding Retro-Reflectors in Flash LIDAR Imagery

Orbital rendezvous and docking of two spacecraft is a topic of continued interest to NASA. For crewed missions, it is frequently the case that the target is cooperative (i.e., is equipped with some sort of navigation aid). If one of the relative navigation instruments is a Flash LIDAR, then this aid may be a suite of retro-reflectors. One of the most difficult aspects of this problem (especially at close range) is finding the retro-reflectors in a Flash LIDAR image amongst a substantial amount of clutter.

Posted in: Briefs, Physical Sciences, Imaging and visualization, Spacecraft guidance, Spacecraft

Novel Hemispherical Dynamic Camera for EVAs

A novel optical design for imaging systems is able to achieve an ultra-wide field of view (UW-FOV) of up to 208°. The design uses an integrated optical design (IOD). The UW-FOV optics design reduces the wasted pixels by 49% when compared against the baseline fisheye lens. The IOD approach results in a design with superior optical performance and minimal distortion.

Posted in: Briefs, Imaging, Physical Sciences, Optics, Spacecraft

Ultrasonic Intake Airflow Meter for Testbeds

The airflow meter measures extremely dynamic phenomena of combustion engines without being affected by ambient influences or sensor contamination.

An ultrasonic intake airflow meter for engine testbed applications was developed. An automotive intake airflow meter must fulfill a series of requirements differentiating it from typical ultrasonic flow meters. First, the data sampling rate of the device must be as high as possible to be able to measure dynamic phenomena of the combustion engine. It is therefore necessary to use broadband ultrasonic transducers capable of sending short signals without post-pulse oscillations. The state-of-the-art piezoelectric transducers cannot fulfill these requirements. For this reason, the FLOWSONIX

Posted in: Briefs, Physical Sciences, Test & Measurement, Combustion and combustion processes, Engines, Test procedures

Convex Hull-Based Plume and Anomaly Detection

A number of deep space missions have imaged plumes at Io, Enceladus, and other smaller bodies. These phenomena provide valuable information regarding these bodies. To date, this imagery has been captured fortuitously. The ability to utilize onboard processing to conduct campaigns capturing large numbers of images and to detect when a plume event is occurring would open up new mission paradigms. Extended temporal campaigns could provide comprehensive detail on these events’ frequency and character.

Posted in: Briefs, TSP, Physical Sciences, Software, Imaging and visualization, Spacecraft

Integrity Sensing With Smart Polymers and Rubber Components on Vehicles

This technology has the potential to improve the quality and provide stability monitoring of materials and connections within seals, tires, and hoses.

This research provides a capacitance-based method for monitoring the integrity of tires and other polymeric products during manufacturing and throughout the useful product life. Tires are complex composite structures composed of layers of formulated cross-linked rubber, textiles, and steel reinforcement layers. Tire production requires precise manufacturing through chemical and mechanical methods to achieve secure attachment of all layers. Tires are subjected to a variety of harsh environments, experience heavy loads, intense wear, heat, and in many cases, lack of maintenance. These conditions make tires extremely susceptible to damage.

Posted in: Briefs, Physical Sciences, Sensors, Tires and traction, Elastomers, Polymers, Smart materials, Wear, Test procedures

The U.S. Government does not endorse any commercial product, process, or activity identified on this web site.