Mechanical & Fluid Systems

High-Efficiency Nested Hall Thrusters for Robotic Solar System Exploration

This work describes the scaling and design attributes of Nested Hall Thrusters (NHT) with extremely large operational envelopes, including a wide range of throttleability in power and specific impulse at high efficiency (>50%). NHTs have the potential to provide the game changing performance, powerprocessing capabilities, and cost effectiveness required to enable missions that cannot otherwise be accomplished. NHTs were first identified in the electric propulsion community as a path to 100-kW class thrusters for human missions. This study aimed to identify the performance capabilities NHTs can provide for NASA robotic and human missions, with an emphasis on 10-kW class thrusters well-suited for robotic exploration. A key outcome of this work has been the identification of NHTs as nearly constant-efficiency devices over large power throttling ratios, especially in direct-drive power systems. NHT systems sized for robotic solar system exploration are predicted to be capable of high-efficiency operation over nearly their entire power throttling range.

Posted in: Mechanics, Mechanical Components, Briefs, TSP

Read More >>

UltraSail CubeSat Solar Sail Flight Experiment

Solar sail will feature new approaches that will result in larger sail areas and larger payloads. UltraSail is a next-generation, highrisk, high-payoff sail system for the launch, deployment, stabilization, and control of very large (km2 class) solar sails enabling high payload mass fractions for interplanetary and deep space spacecraft. UltraSail is a non-traditional approach to propulsion technology achieved by combining propulsion and control systems developed for formation- flying microsatellites with an innovative solar sail architecture to achieve controllable sail areas approaching 1 km2, sail subsystem area densities approaching 1 g/m2, and thrust levels many times those of ion thrusters used for comparable deep space missions. UltraSail can achieve outer planetary rendezvous, a deep-space capability now reserved for high-mass nuclear and chemical systems.

Posted in: Mechanics, Mechanical Components, Briefs

Read More >>

Acquisition and Retaining Granular Samples via a Rotating Coring Bit

This device is used in granular sample handling, and as a stand-alone regolith acquisition bit. This device takes advantage of the centrifugal forces that are generated when a coring bit is rotated, and a granular sample is entered into the bit while it is spinning, making it adhere to the internal wall of the bit, where it compacts itself into the wall of the bit. The bit can be specially designed to increase the effectiveness of regolith capturing while turning and penetrating the subsurface. The bit teeth can be oriented such that they direct the regolith toward the bit axis during the rotation of the bit. The bit can be designed with an internal flute that directs the regolith upward inside the bit. The use of both the teeth and flute can be implemented in the same bit. The bit can also be designed with an internal spiral into which the various particles wedge.

Posted in: Mechanics, Mechanical Components, Briefs, TSP

Read More >>

Counterflow Regolith Heat Exchanger

A problem exists in reducing the total heating power required to extract oxygen from lunar regolith. All such processes require heating a great deal of soil, and the heat energy is wasted if it cannot be recycled from processed material back into new material.

Posted in: Mechanics, Mechanical Components, Briefs

Read More >>

Very-Low-Cost, Rugged Vacuum System

Applications include portable analytical instruments such as mass spectrometers and leak detectors. NASA, DoD, DHS, and commercial industry have a need for miniaturized, rugged, low-cost vacuum systems. Recent advances in sensor technology have led to the development of very small mass spectrometer detectors as well as other miniature analytical instruments. However, the vacuum systems to support these sensors remain large, heavy, and power-hungry. To meet this need, a miniaturized vacuum system was created based on a very small, rugged, and inexpensive- to-manufacture molecular drag pump (MDP). The MDP is enabled by the development of a miniature, very-high- speed, rugged, low-power, brushless DC motor optimized for wide temperature operation and long life. Such a pump represents an order-of-magnitude reduction in mass, volume, and cost over current, commercially available, state-of-the-art vacuum pumps.

Posted in: Mechanics, Mechanical Components, Briefs, TSP

Read More >>

Mechanism for Deploying a Long, Thin-Film Antenna From a Rover

The deployment mechanism consists of two rollers to automatically deploy the antenna at a rate proportional to the wheel speed. Observations with radio telescopes address key problems in cosmology, astrobiology, heliophysics, and planetary science including the first light in the Universe (Cosmic Dawn), magnetic fields of extrasolar planets, particle acceleration mechanisms, and the lunar ionosphere. The Moon is a unique science platform because it allows access to radio frequencies that do not penetrate the Earth's ionosphere and because its far side is shielded from intense terrestrial emissions. A radio antenna can be realized by using polyimide film as a substrate, with a conducting substance deposited on it. Such an antenna can be rolled into a small volume for transport, then deployed by unrolling, and a robotic rover offers a natural means of unrolling a polyimide film-based antenna. An antenna deployment mechanism was developed that allows a thin film to be deposited onto a ground surface, in a controlled manner, using a minimally actuated rover.

Posted in: Mechanics, Mechanical Components, Briefs, TSP

Read More >>

How to Optimize Performance and Minimize Size in High Speed Applications

Electric motors are continuously evolving with the constant release of new material in the market. Today, NeoFe magnets are reaching 50 MGoe and new lamination materials offering limited losses, allow the use of electric motors at very high speed. For each application it’s crucial to understand in detail the specifications in order to offer the optimum design, Portescap has developed few motor technologies in order to be address each application with an optimal solution.

Posted in: Mechanics, Mechanical Components, White Papers

Read More >>

White Papers

Changing Face of Robotics
Sponsored by Maplesoft
The Self-Driving Car
Sponsored by HP
Improving Medical Devices with Force Sensing Technology
Sponsored by tekscan
Unique Method for Orifice Production
Sponsored by Bird Precision
Fundamentals of Vector Network Analysis Primer
Sponsored by Rohde and Schwarz A and D
3D PRINTERS VS. 3D PRODUCTION SYSTEMS: 10 Distinguishing Factors to Help Select a System
Sponsored by Stratasys

White Papers Sponsored By: