Mechanical & Fluid Systems

Multifunctional Tanks for Spacecraft

A document discusses multifunctional tanks as means to integrate additional structural and functional efficiencies into designs of spacecraft.  Whereas spacecraft tanks are traditionally designed primarily to store fluids and only secondarily to provide other benefits, multifunctional tanks are designed to simultaneously provide multiple primary benefits. In addition to one or more chamber(s) for storage of fluids, a multifunctional tank could provide any or all of the following:

Posted in: Briefs, TSP, Mechanical Components, Mechanics, Containers, Storage, Spacecraft


Mobile Robot for Exploring Cold Liquid/Solid Environments

This tethered robot could float, swim, crawl, and sample environmental materials. The Planetary Autonomous Amphibious Robotic Vehicle (PAARV), now at the prototype stage of development, was originally intended for use in acquiring and analyzing samples of solid, liquid, and gaseous materials in cold environments on the shores and surfaces, and at shallow depths below the surfaces, of lakes and oceans on remote planets. The PAARV also could be adapted for use on Earth in similar exploration of cold environments in and near Arctic and Antarctic oceans and glacial and sub-glacial lakes.

Posted in: Briefs, TSP, Mechanical Components, Mechanics, Cold weather, Autonomous vehicles, Off-highway vehicles and equipment, Spacecraft


System Would Acquire Core and Powder Samples of Rocks

A sampling system would be built around an ultrasonic/sonic drill corer. A system for automated sampling of rocks, ice, and similar hard materials at and immediately below the surface of the ground is undergoing development. The system, denoted a sample preparation, acquisition, handling, and delivery (SPAHD) device, would be mounted on a robotic exploratory vehicle that would traverse the terrain of interest on the Earth or on a remote planet. The SPAHD device would probe the ground to obtain data for optimization of sampling, prepare the surface, acquire samples in the form(s) of cores and/or powdered cuttings, and deliver the samples to a selected location for analysis and/or storage.

Posted in: Briefs, TSP, Mechanical Components, Mechanics, Soils, Robotics, Test equipment and instrumentation, Autonomous vehicles, Spacecraft


Producing Quantum Dots by Spray Pyrolysis

Sizes of quantum dots are determined by sizes of sprayed drops.An improved process for making nanocrystallites, commonly denoted quantum dots (QDs), is based on spray pyrolysis. Unlike the process used heretofore, the improved process is amenable to mass production of either passivated or non-passivated QDs, with computer control to ensure near uniformity of size.

Posted in: Briefs, Mechanical Components, Mechanics, Forming, Spraying, Nanotechnology


Ultrasonically Actuated Tools for Abrading Rock Surfaces

These offer the same advantages as do ultrasonically actuated drilling and coring tools. An ultrasonic rock-abrasion tool (URAT) was developed using the same principle of ultrasonic/sonic actuation as that of the tools described in two prior NASA Tech Briefs articles: “Ultrasonic/Sonic Drill/Corers With Integrated Sensors (), Vol. 25, No. 1 (January 2001), page 38 and “Ultrasonic/Sonic Mechanisms for Drilling and Coring” (), Vol. 27, No. 9 (September 2003), page 65. Hence, like those tools, the URAT offers the same advantages of low power demand, mechanical simplicity, compactness, and ability to function with very small axial loading (very small contact force between tool and rock).

Posted in: Briefs, TSP, Mechanical Components, Mechanics, Sensors and actuators, Soils, Tools and equipment, Drilling, Acoustics


Active Struts With Variable Spring Stiffness and Damping

These struts would act as linear actuators and controllable shock absorbers.Controllable active struts that would function as linear actuators with variable spring stiffness and damping have been proposed as components of advanced suspension systems of future wheeled ground vehicles. The contemplated advanced suspension systems would include computer-based control subsystems that would continually adjust the actuator responses to obtain optimal combinations of safety and comfort under operating conditions ranging from low speeds over smooth roads to high speeds over rough, unpaved ground. The proposed struts and suspension systems were originally intended for use in military vehicles, but there could also be a broad commercial market for them in trucks and sport utility vehicles.

Posted in: Briefs, TSP, Mechanical Components, Mechanics, Active suspension systems, Springs, Military vehicles and equipment


Estimation of Stability and Control Derivatives of an F-15

Parameters can be estimated in nearly real time for use in adaptive flight control. A technique for real-time estimation of stability and control derivatives (derivatives of moment coefficients with respect to control-surface deflection angles) was used to support a flight demonstration of a concept of an indirect-adaptive intelligent flight control system (IFCS). Traditionally, parameter identification, including estimation of stability and control derivatives, is done post-flight. However, for the indirect-adaptive IFCS concept, parameter identification is required during flight so that the system can modify control laws for a damaged aircraft.

Posted in: Briefs, Mechanical Components, Mechanics, Stability control, Mathematical analysis, Adaptive control, Flight control systems


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