Special Coverage

Self-Healing Wire Insulation
Thermomechanical Methodology for Stabilizing Shape Memory Alloy (SMA) Response
Space Optical Communications Using Laser Beams
High Field Superconducting Magnets
Active Response Gravity Offload and Method
Strat-X
Sonar Inspection Robot System
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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

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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

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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

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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

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Flexible Ablator for Thermal Protection

Simple and versatile manufacturing approach to produce heat shields. NASA has developed a class of low-density, flexible ablators that can be fabricated into heat-shields capable of being packaged, stowed, and deployed in space. The key characteristics of this new ablative thermal protection system (TPS) are its flexibility, conformability, and tailor-ability. Flexibility allows the material to be stowed in the shroud of a launch vehicle and deployed in space, without compromising functionality. Conformability allows the material to be attached to a curved surface without precise and expensive machining. Tailor-ability allows the density and composition to be optimized for the requirements. This flexible TPS can be used to cover and thermally protect a large, blunt shape that provides aerodynamic drag during hyper-velocity atmospheric flight. It can be used with minimal modification for large aeroshells whose deployment relies mainly on mechanical means and through inflation. Such devices are called Hypersonic Inflatable Aerodynamic Decelerators (HIADs). Large blunt body aeroshells may be used to deliver large payloads (40 metric tons) to the surface of Mars.

Posted in: Briefs, Materials

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Resistive Heating Method for TPS Property Measurements

A unique ultrasonic-based technique has been developed to measure temperature profiles in materials used in thermal protection systems (TPS). The technology requires measurements of the thermal expansion coefficient and the ultrasonic velocity for these materials as a function of temperature in order to determine the variation of ultrasonic propagation speed with temperature. Generally, this is done by slowly heating materials to a set temperature so that the samples are isothermal.

Posted in: Briefs, Materials

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Measuring Bond Site Concentration on the Intrinsic Aerogel Surface Through Chemisorption of Chlorosilanes

This work involves development of aerogel to be used as a passive absorption media — effectively a concentrator of trace organics — that can be detected by optical techniques. Such a trace organic detection scheme is very different from all other current techniques, and has the potential to significantly enhance the sensitivity of detection of volatile species. The aerogel concentrator provides an integrated measurement over long periods of time (months, years), as opposed to mass spectroscopy, which tests at a given moment.

Posted in: Briefs, Materials

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