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Power and Signal Integrity Findings in a FPGA Layout for an Aerospace Application
Design principles concerning the use of FPGA are of particular importance in aerospace applications since the neglect of such design principles can cause catastrophic effects in aerospace system, as it will be explained in this paper. FPGA design rules such as power conditioning and signal integrity for properly interfacing high speed FPGA with its interface circuits are discussed in this paper as it relates to aerospace systems. Signal integrity to avoid crosstalk within a FPGA has not been a great concern because most of the attention over the years had been on signal integrity at the PCB level. However, this paper shows a real example of crosstalk within a FPGA in an aerospace application.
Entropy-based Adaptive Design for Contour Finding and Estimating Reliability
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Are We Alone? NASA Technologies to Find Life Beyond Earth and Answers to Other Science Questions
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Are We Alone? NASA Technologies to Find Life Beyond Earth and Answers to Other Science Questions
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Finding and Fixing Food System Emissions: The Double Helix of Science and Policy
Improving estimates of greenhouse gas (GHG) emissions from food production, supply, consumption, and disposal is fundamental to identifying effective policy solutions. Through broader awareness of the food-climate nexus, climate mitigation as well as resilience can be enhanced. However, work is needed to address knowledge gaps, promote better policies and improve public understanding of issues related to the food system and climate change. The intention of this paper is not only to highlight the need for better scientific understanding of the processes through which GHGs are emitted—from production to processing, from supply chains and retail to food preparation and waste (figure 1)—but also to integrate science and policy in order to scale up impact on climate change action.
Initial Findings in Full-Shell Active Optics
The realization of active full-shell x-ray optics will provide ground-breaking capability for future missions. Future X-ray missions, such as Lynx, require high angular-resolution, large effective area, and as wide a field of view(FOV) as possible. It is currently not possible to perform high-resolution imaging of both wide and narrow FOVs with a single X-ray telescope. In this paper, we discuss the use of actuators to switch the optical surface of full-shell x-ray optics between prescriptions optimized for narrow-field and wide-field viewing, as well as correct for low-spatial-frequency errors in the optics. Previously, a pathfinder was developed using finite-element modeling(FEM). Using a combination of the model’s influence functions, the capacity of active full-shell optics was shown to switch between prescriptions with 92% accuracy. Another benefit of the analytical pathfinder was its ability to correct low-spatial frequency errors, which comprise a large percentage of the MSFC full-shell x-ray optics root-mean-square (RMS) slope error. In order to verify the pathfinder, a surface-parallel actuator was bonded to a nickel-replicated coupon. After the actuator was bonded to the coupon, the slope of the surface was measured while the actuator was activated. The proof-of-concept demonstrator development, the influence function data, and the resulting implications on the analytical pathfinder are reported and discussed.