Tech Briefs

Multi-Spoked Wheel Assembly

This innovation can be applied to robots used by first responders and others as a single ground-traction mechanism in a variety of environments. NASA Glenn researchers have developed a spoked drive mechanism for robots and other vehicles that is capable of two rotational modes. This robust ground traction (drive) assembly for remotely controlled vehicles operates smoothly not only on surfaces that are flat, but also upon surfaces that include rugged terrain, snow, mud, and sand. The assembly includes a sun gear and a braking gear. The sun gear is configured to cause rotational force to be applied to second planetary gears through a coupling of first planetary gears. The braking gear is configured to cause the assembly (or the second planetary gears) to rotate around the braking gear when an obstacle or braking force is applied.

Posted in: Briefs, Mechanical Components

Read More >>

Nanotube-Based Device Cooling System

Carbon nanotubes (CNTs) are being studied for applications in high-strength/low-weight composites and other applications. Recent research on thermal dissipation materials for high-power electronic devices is generating a lot of interest in various industries. NASA has developed a method for cooling a device, such as an electronic device, that produces extreme heat that must be dissipated. CNTs have attracted much attention due to their extraordinary mechanical and unique electronic properties. Computer chips have been subjected to higher and higher thermal loads and it is challenging to find new ways to perform heat dissipation. As a result, heat dissipation demand for computer systems is increasing dramatically. CNTs, which are known to provide high thermal conductivity and to be small and flexible, are suitable for cooling these electronic devices. One critical problem is provision of a compliant, usable composite of CNTs with a material that meets other needs for heat dissipation.

Posted in: Briefs, Mechanical Components

Read More >>

A Method for Accurate Load/Position Control of Rigidly Coupled Electromechanical Actuators

NASA has developed a technique designed to prevent cross-coupling in systems where two or more linear electro-mechanical actuators (EMA) are rigidly connected and are in danger of becoming cross-coupled. In such systems where the linked EMAs are commanded to achieve two distinct goals, such as position and load control, control problems often arise — especially at higher load and linear velocity levels. Both position and load control become inaccurate and in certain situations, stability of the overall system may be compromised. The NASA-developed approach mitigates the problem and achieves both accurate position following and desired load levels between the two (or more) actuators.

Posted in: Briefs, Mechanical Components

Read More >>

Ultralight Self-Deployable Solar Sails

This technology could be applied to self-deployable shelters, camping tents, sunshades, and house construction.Deployment of large structures such as solar sails relies typically upon electromechanical mechanisms, mechanically expandable or inflatable booms, launch restraints, controls, and other mechanisms that drastically increase the total mass, stowage volume, and areal density. The primary performance parameter for solar sails is areal density, which determines the acceleration of the sail. Present technology allows the solar sail areal density to be around 20 g/m2, and that permits only nearby demonstration missions.

Posted in: Briefs, Mechanical Components, Mechanics

Read More >>

Ultra-Compact Heat Rejection System

Radiator panels are the baseline heat rejection approach for most space systems. This approach is sound, but requires a large amount of surface area to radiate the anticipated heat load. The large panels require support structures to hold them in place and prevent damage. These structures impact mass and cost. Additionally, it is not practical to launch, transport, integrate, and relocate large panels as monolithic units. For this reason, a foldable scissor assembly is envisioned to stow the panels compactly and extend them before system startup. The moving parts and flexible fluid connections required for this approach add complexity and potential failure modes to the system. Some mission plans also require power system mobility for exploration well beyond the base camp. For this scenario, the radiator assemblies must be retracted, stowed, and redeployed each time the system is moved. These activities require time and effort, and they expose the radiator panels and associated mechanisms to damage risk. Even when properly stowed, the relatively thin panels could be damaged during transportation.

Posted in: Briefs, Mechanical Components, Mechanics

Read More >>

Transformable and Reconfigurable Entry, Descent, and Landing Systems and Methods

The Adaptable, Deployable Entry Placement Technology (ADEPT) concept is a mechanically deployable, semi-rigid aeroshell entry system capable of achieving low ballistic coefficient during entry for planetary or Earth return missions. The decelerator system offers a lighter-weight solution to current rigid, high-ballistic-coefficient aeroshells and enables missions that are currently not feasible with rigid aeroshell construct.

Posted in: Briefs, Mechanical Components, Mechanics

Read More >>

Thermomechanical Methodology for Stabilizing Shape Memory Alloy (SMA) Response

SMA training can be completed in a matter of minutes, rather than days or even weeks. Shape memory alloys (SMAs), sometimes known as “smart metals,” provide a lightweight, solid-state alternative to conventional actuators and switches, such as hydraulic, pneumatic, or motor-based systems. To function properly, SMAs must be “trained” to return to a previous form when heated, and innovators at NASA’s Glenn Research Center have developed a remarkable new method of completing this training at a fraction of the time and cost of conventional training techniques. Glenn’s technique uses mechanical cycling, rather than more complicated and time-consuming thermal cycling, to train SMAs before implementation. In addition, this new approach to training allows SMAs to be applied to complex geometric components, so that they may be used in a broader number of applications.

Posted in: Briefs, Materials

Read More >>

The U.S. Government does not endorse any commercial product, process, or activity identified on this web site.