In 2002, NASA announced it was closing the National Full-Scale Aerodynamics Complex (NFAC) Wind Tunnels at Moffett Field, CA and the last customer test was completed in February 2003. In 2005, the Department of Defense (DoD) announced that NFAC operations and maintenance would be returned to service and funded as part of the DoD budget. A portion of the NFAC Reactivation Project was tasked with the design, installation, and checkout of new state-of-the-art high speed/high storage, Data Acquisition Systems (DAS) using standard Windows computers and operating platforms within the facility. Each system provides capabilities for acquiring, pre-processing (resampling from time-based to position-based data for rotor testing), processing (converting raw data to engineering units and deriving second-level parameters), displaying, recording, and reducing rotorcraft and fixed-wing test article measurements for approximately 900 channels and 15,000 derived parameters. The channels are divided into four separate subsystems: a Dynamic Data Acquisition System (DDAS), a Basic Data Acquisition System (BDAS), a Safety of Flight Data Acquisition System (SoFDAS), and a Steady-State Data Acquisition System (SDAS). The rotor-based DDAS acquires 256 channels of high speed load cell, pressure and acoustic channels. The rotor-based BDAS provides for acquisition of 240 channels of model balance signals, tunnel balance signals, and strain gages. The SoFDAS acquires 96 channels and provides real-time limit checking functions to ensure the health of the unit under test and the test apparatus systems. The SDAS provides acquisition of low speed, non-rotor based signals consisting of 224 wall pressure channels, 64 in-model pressure channels, 48 thermocouple temperatures, and various tunnel parameters such as barometric pressure, humidity, etc. The total acquisition and storage rate for the system exceeds 80 Megabytes per second. A Data Storage System with a 6.75 terabyte disk array archives all data and provides it to other external computers for further processing and analysis. Because tasks are distributed among several computers, data collection and storage rates are maintained while data is converted to engineering unit (EU) data and provided to operator and customer displays in pseudo real time. Data accuracy and bandwidth are maintained by utilizing smart data acquisition hardware such as VXI Technology VXI, Pressure Systems Incorporated Ethernet Scanner, and VXI Technology LXI Temperature systems. The latest distributed version of Jacobs' Test SLATE is used as the software platform.
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