Mechanical/​Mechatronics

A high-temperature ceramics-based composite exhibits superior heat and oxidation resistance and frictional properties. The material comprises a dense carbon-fiber-reinforced SiC-infiltrated composite or a dense SiC-infiltrated composite with granular carbon dispersed. It shows excellent machineability and frictional properties....

A report discusses the design of the rocker-bogie suspensions of the Mars Exploration Rover vehicles, which were landed on Mars in January 2004. Going beyond the basic requirements regarding mobility on uneven terrain, the design had to satisfy requirements (1) to enable each suspension to contort...

A document describes a three-stage passive radiative cooler for a cryogenic spectrometer to be launched into a low orbit around the Moon. This cooler is relatively lightweight and compact, and its basic design is scalable and otherwise adaptable to other applications in which there are...

A paper describes the Sample Caching Subsystem (SCS), a method for storing planetary core and soil samples in a container that seals the samples away from the environment to protect the integrity of the samples and any organics they might contain. This process places samples in individual sleeves that are sealed within a...

A report discusses a new multi-turn, multi-lead design for the first generation PT-1 (Plasmoid Thruster) that produces thrust by expelling plasmas with embedded magnetic fields (plasmoids) at high velocities. This thruster is completely electrodeless, capable of using in-situ resources, and...

A short document summarizes the redesign of a xenon-ion spacecraft thruster to increase its operational lifetime beyond a limit heretofore imposed by nonuniform ion-impact erosion of an accelerator electrode grid. A peak in the ion current density on the centerline of the thruster causes...

A paper discusses general problems in estimation and control of the states (positions, attitudes, and velocities) of spacecraft flying in formation, then addresses the particular formation-flying-control problem of synchronization of deadbands. The paper presents a...

A water-flow test facility has been built to enable measurement of dynamic transfer functions (DTFs) of cavitating pumps and of inducers in such pumps. Originally, the facility was intended for use in an investigation of the effects of cavitation in a rocket-engine low-pressure oxygen...

A report proposes the development of a system for launching payloads into orbit at about one-fifth the cost per unit payload weight of current systems. The system would be based on the formerly secret PILOT micro-satellite-launching system developed in response to the Soviet launch of Sputnik-1....

An improved quick-release pin mechanism supplants a prior such mechanism in which the pin bears a shear load to hold two objects together. The prior mechanism, of a ball-locking design, can fail when vibrations cause balls to fall out. The load-bearing pin is an outer tube with a handle at one end (hereafter...

A proposal investigates alternatives to the present "bumper" method of protecting spacecraft against impacts of meteoroids and orbital debris. The proposed method is based on a British highvoltage- capacitance technique for protecting armored vehicles against shapedcharge warheads.

A modification of the basic design of cobra probes provides for relatively easy replacement of broken thermocouples. [Cobra probes are standard tube-type pressure probes that may also contain thermocouples and that are routinely used in wind tunnels and aeronautical hardware. They are so named...

A report describes an interface for utilizing some of the mobility features of a mobile robot for general-purpose manipulation of tools and other objects. The robot in question, now undergoing conceptual development for use on the Moon, is the All-Terrain Hex-Limbed Extra-Terrestrial Explorer (ATHLETE) rover, which is...

Inspired by the device used to find lost coins in the sand, Johns Hopkins University biomedical engineering students have invented a small handheld metal detector to help doctors locate hidden orthopedic screws that need to be removed from patients' bodies. The device emits a tone that rises in pitch as the surgeon moves closer...

A report presents an algorithm that solves the following problem: Allocate the force and/or torque to be exerted by each thruster and reaction-wheel assembly on a spacecraft for best performance, defined as minimizing the error between (1) the total force and torque commanded by the spacecraft...

A paper describes a computationally efficient method of optimizing trajectories of spacecraft driven by propulsion systems that generate low thrusts and, hence, must be operated for long times. A common goal in trajectory-optimization problems is to find minimum-time, minimum-fuel, or...

A report discusses the development of a computational model of a Mars Explorer Rover maneuvering across terrain under varying conditions. The model is used to increase understanding of the rover dynamics. Increased understanding is helpful in planning further tests and in extending the...

A document presents further information on the subject matter of “Controlling Herds of Cooperative Robots” (NPO-40723), NASA Tech Briefs, Vol. 30, No. 4 (April 2006), page 81. To recapitulate: A methodology for controlling a herd of cooperative and autonomous mobile robots exploring the surface...