Mechanical Components

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 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.

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 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....

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...

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...

An electromagnetic actuator is a highly sensitive motion control device that employs more reliable and cleaner electromagnetic technologies to replace slower, less precise, larger, noisier, and environmentally unfriendly hydraulic omponents. This patented technology uses an armature in the form of a piston that moves on its own...

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 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 algorithms for guidance and control (G&C) of a spacecraft maneuvering near a planet, moon, asteroid, comet, or other small astronomical body. The algorithms were developed following a model- predictive-control approach along with a convexification of the governing...

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...

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 report describes recent accomplishments of a continuing effort to develop the vapor-phase catalytic ammonia removal (VPCAR) process for recycling wastewater for consumption by humans aboard a spacecraft in transit to Mars. The VPCAR process is implemented by a system of highly integrated...

Five reports address different aspects of development of tethers to be deployed from spacecraft in orbit around the Earth. The first report discusses proposed optoelectronic tracking of retroreflective objects located at intervals or of retroreflective coats along the entire length of a tether to measure...

A report presents a design concept for an instrumented robotic vehicle (rover) to be used on a future mission of exploration of the planet Mars. The design incorporates a nuclear fission power system to provide long range, long life, and high power capabilities unachievable through the use of...

A paper presents an algorithm to initialize a formation of N distributed spacecraft in deep space. Such formations will enable variable-baseline interferometers in future NASA missions designed to study the structure and origin of the universe. The algorithm described in the paper reflects some...