Mechanical/​Mechatronics

A document discusses the design of orbits of spacecraft for relaying communications between Earth stations and robotic and human explorers in craters in one of the polar regions on the Moon. In simplest terms, the basic problem is to design a constellation of orbits to provide continuous and...

A method that involves the use of fictitious plate elements denoted bridge plates has been developed for representing the stiffnesses of fillets in finiteelement calculations of deflections, stresses, and strains in structures. In the absence of this method, it would be necessary to...

An enlarged, high-temperature -compliant foil bearing has been built and tested to demonstrate the feasibility of such bearings for use in aircraft gas turbine engines. At 150 mm in diameter, this is the largest foil bearing known to date. This bearing is a scaled-up version of a patented 100-mm-diameter...

A document describes a concept for an inertial sensor for measuring the rotation of an inertially stable spacecraft around its center of gravity to within 100 microarc- seconds or possibly even higher precision. Whereas a current proposal for a spacecraft-rotation sensor of this accuracy...

A document poses, and suggests a program of research for answering, questions of how to achieve autonomous operation of herds of cooperative robots to be used in exploration and/or colonization of remote planets. In a typical scenario, a flock of mobile sensory robots would be deployed in a previously...

A report discusses a proposed system for mounting loaded pallets in the cargo bay of a next-generation space-shuttle-like spacecraft, such that the center of mass of the cargo would lie within a 1-in. (2.54- cm) cube that would also contain the center of mass of the spacecraft. The system...

A report discusses a 7-meter-diameter reflectarray antenna that has been conceived in a continuing effort to develop large reflectarray antennas to be deployed in outer space. Major underlying concepts were reported in three prior NASA Tech Briefs articles: "Inflatable Reflectarray Antennas" (NPO-20433), Vol....

Buffet loads on aft aerodynamic surfaces pose a recurring problem on most twin-tailed fighter airplanes: During maneuvers at high angles of attack, vortices emanating from various surfaces on the forward parts of such an airplane engine inlets, wings, or other fuselage appendages) often burst,...

A vacuum compressor has been designed to compress CO2 from ˜1 psia (˜6.9 kPa absolute pressure) to ˜75 psia (˜0.52 MPa), to be insensitive to moisture, to have a long operational life, and to be lightweight, compact, and efficient. The compressor consists mainly of (1) a...

The upper part of the figure depicts an actuator that comprises two mechanically biased piezoelectric benders hinged together at their ends and equipped with tabs at their mid-length points for attachment to the relatively moving objects that are to be actuated. In the example of the...

Non-aerodynamic mechanical devices are under consideration as means to augment the stability of miniature autonomous and remotely controlled aircraft. Such aircraft can be used for diverse purposes, including military reconnaissance, radio communications, and safety-related monitoring of wide...

Launch Vehicle External Sound Pressure is a computer program that predicts the ignition-overpressure and the acoustic pressure on the surfaces and in the vicinity of a rocket and launch pad during launch. The program generates a graphical user interface (GUI) that gathers input data from the user....

An assembly of devices provides for both humidification of the reactant gas streams of a fuel cell and removal of the product water (the water generated by operation of the fuel cell). The assembly includes externally-sensing forward-pressure regulators that supply reactant gases (fuel and...

A report discusses the design of a rover lift mechanism (RLM) — a major subsystem of each of the Mars Exploration Rover vehicles, which were landed on Mars in January 2004. The RLM had to satisfy requirements to (1) be foldable as part of an extremely dense packing arrangement and (2) be capable...