• A PC WORKSTATION FOR SPACECRAFT FACTORY INTEGRATION & TEST

      Losik, Len; L-3 Communications (International Foundation for Telemetering, 1997-10)
      PC technology has progressed to the point that it can very effectively support commercial geostationary spacecraft design, manufacture, test, launch, ground station, and on-orbit mission control activities. Many of the manufacturers that provide VME spacecraft test hardware and software are now providing the same functions and performance for the PC. A PC workstation equipped with single and multiple Pentium processors and Windows NT software can support single and multiple uplinks/downlinks and provide client/server capabilities that perform traditional UNIX client/server operations. Such a PC workstation can provide the functionality, features, and performance necessary for commercial spacecraft board-level test, unit-level test, subsystem-level test, spacecraft bus and payload integration, and ground station monitoring and control, as well as on-orbit mission control activities.
    • A PC-BASED RF TEST CONSOLE FOR INTEGRATION & TEST ON NASA’S LUNAR PROSPECTOR SPACECRAFT

      Losik, Len; L-3 Communications (International Foundation for Telemetering, 1997-10)
      Lunar Prospector’s project engineering staff selected a Windows PC platform as the RF test console for the Lunar Prospector spacecraft. The spacecraft test team chose the PCbased RF test console because the PC provides a low-cost, common platform with a graphical user interface. The PC provides point-and-click, menu-driven windows that are common throughout the satellite factory. The PC RF test console is being used to exercise the Lunar Prospector spacecraft RF link for RF commanding, telemetry, and ranging signals during factory test, including thermal vacuum chamber testing. For spacecraft command and control at the factory, the PC-based RF test console is networked to a UNIX workstation over RS-422. The PC RF test console and spacecraft interface are controlled through a coax switch residing in a test rack next to the workstation. The PC RF test console is connected directly to the Lunar Prospector spacecraft using coax cable through the spacecraft Telemetry, Commanding, & Ranging (TC&R) RF antenna hat for both transmit and receive functions. The PC RF test console is also connected hard-line to the spacecraft transponder through the transponder RS-422 connection. This connection provides the ability for spacecraft telemetry to be received at the PC at RF or baseband. The same hard-line spacecraft telemetry data is provided to the UNIX workstation for comparison. NASA’s Lunar Prospector project is the first of the Discovery series of “faster, better, cheaper” missions to be competitively awarded. Lunar Prospector project funding was capped by NASA to ensure that no overruns would occur. The mission was funded to support the scientific community’s desire to verify the presence of ice on the moon and collect environmental data to understand the dynamics that may have led to polar ice deposits. The Lunar Prospector mission received funding in 1996 with a launch planned for September 1997