Scientists at NASA’s Marshall Space Flight Center have developed a method to improve the crystal quality of II-VI semiconductor wafers. The production method has the potential to improve ingot yields by as much as 60 percent by enhancing the solidification process with a special added technique that allows nucleation control at the critical time during cooling, producing a much larger, single-crystal region in the ingot. Existing production techniques cannot consistently produce large single crystals, resulting in typically low yields for commercial applications. NASA’s technology offers the prospect of improved yields and reduced material costs, which would in turn reduce the cost of detectors employing these materials and promote their use in new imaging markets. Although the method potentially can be used with any II-VI material, it is particularly suited for cadmium telluride (CdTe) and cadmium zinc telluride (CdZnTe) ingot growth. This easily adaptable and scalable technique is now the standard process for Cd ZnTe ingot growths performed at NASA.

Researchers at NASA’s Marshall Space Flight Center have developed a multi-functional composite material that can form the basis of structural components while also providing protection against radiation in a space environment. When layered, this innovation provides cosmic and solar radiation shielding as well as structural functionality—with a strength-to-weight ratio superior to that of aluminum. The technology is composed of inexpensive, readily available commercial materials and is fabricated using proven manufacturing methods. As such, it offers a mission-enabling, cost-effective option for decreasing spacecraft weight by combining shielding and structure. This reduces total vehicle mass (allowing for simplified propulsion systems) while enhancing radiation protection for crew members and electronics. The material can also be engineered to provide defense against micro-meteoroid impacts, without appreciable effect on its structural qualities. NASA has applied for patent protection for this technology.

Researchers at NASA’s Marshall Space Flight Center have patented a method for simultaneously fabricating a protective coating for a crucible and creating multi-purpose channels within the coating. The innovation allows a metal coating with a uniform, desired thickness to be deposited on a crucible in a three-step process. The coating protects the generally brittle crucible and the resultant channels can be used for a variety of purposes, such as pathways for solid objects and flow paths for liquid or gas coolants. In some instances, the channels can be filled with known gases and then sealed so that crucible failure is indicated by instruments that detect the gases.

Scientists at NASA’s Marshall Space Flight Center have patented a design that can shield spacecraft from the impact of high-speed objects. The innovation has a square-wave honeycomb pattern with cells alternating at oblique angles, enabling the cells to be bonded or brazed to one another and forming a sandwich structure. Rather than having a fixed structure, the material can be adjusted to control the size of the honeycomb openings but keep the sides of the honeycomb parallel to each other. Based on its application, the structure design can take many forms—rectangular, square, trapezoidal, sinusoidal—either alone or combined with each other to achieve the desired effect or deflection. This flexibility will allow the material to be more lightweight compared with previous designs that have used extra thicknesses of material or several shields with space between them, increasing weight and volume.

Innovators at NASA’s Marshall Space Flight Center have patented a method for detecting cracks and corrosion on surfaces and in joint and weld regions of metallic structures. This method extends the intended use of liquid/vapor-phase corrosion inhibitors (LVCIs), which mitigate or eliminate corrosion on metallic structures, to applications for penetrant dyes in neutron radiography (and possibly x-radiography). LVCIs are applied to protect metallic structures such as thrust vector frames within rocket booster systems. The conventional method of testing for cracks or corrosion after LVCI application is visual inspection; however, this is labor intensive and may not fully detect problems, particularly in areas that are covered with paint or located in joint or weld regions. With Marshall’s innovation, the LVCI absorbs the neutron ray to reveal cracks, corrosion, or other defects that may be missed by visual or ultrasonic inspection.