The objective of the 9-Meter Slaving System is to transmit Launch Trajectory Acquisition System (LTAS) data from one of multiple incoming data streams to the 9-Meter antenna control unit using a synchronous serial modem. The data stream is determined by a 9-Meter telemetry operator's selection via a graphical user interface (GUI).

The 9-Meter Slaving System consists of software and hardware that allow the 9-Meter telemetry operator to acquire LTAS data via either network User Datagram Protocol (UDP) packets and/or synchronous serial modem from multiple sources, select one of these data streams, and transmit LTAS data to the 9-Meter antenna control unit via a synchronous serial modem.

The system contains the following software and hardware: LTAS Source Slaving Selector (LS3) software; Universal Translate, Record, and Analyze (ULTRA) system; LTAS Source Slaving Selector (LS3) Analyzer software; a variety of supporting non-NASA applications such as 7-Zip, Adobe Reader, Anaconda Python, FileZilla, JRE, Mozilla Firefox, Notepad++, OpenOffice, Python, and Wireshark; NetAcquire server for the ULTRA system; and rack-mount PC computer with Microsoft Windows 7 operating system for the rest of the software.

The LS3 application acquires LTAS packets via a UDP network to then transmit LTAS data via the UDP network. For the other sources that supply LTAS data via a synchronous serial modem, the ULTRA is used to convert and retransmit this data to the LS3 application via the UDP network. For slaving LTAS data, the LS3 application will transmit data to the ULTRA via the UDP network; the ULTRA will then convert and transmit it to synchronous serial data for the 9-Meter antenna control unit. The LS3 Analyzer application is used to convert recorded data, which is in binary format generated by the LS3 application, to human-readable files. The Network Countdown Time Protocol (NCTP) is used for time synchronizing in the LS3 application. The NCTP is generated and provided by the ULTRA system using timing information from the IRIG-B and Pseudo-IRIG-B (Inter-Range Instrumentation Group, format B).

This work was done by Nathan Riolo, Woong Seo, and Walter Wehner of NASA Wallops Flight Facility for Goddard Space Flight Center. NASA is seeking partners to further develop this technology through joint cooperative research and development. For more information about this technology and to explore opportunities, please contact Scott Leonardi at This email address is being protected from spambots. You need JavaScript enabled to view it. GSC-17404-1

NASA Tech Briefs Magazine

This article first appeared in the May, 2017 issue of NASA Tech Briefs Magazine.

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