Space Very Long Baseline Interferometry (SVLBI) Mission Operations

The first space very long baseline interferometry (SVLBI) mission—the VLBI Space Observatory Program (VSOP)—using an 8-m telescope in orbit, has been successfully operated since 1997, and several follow-on missions are in development or under discussion. The SVLBI missions are among the most complex space science missions to date in terms of operations and coordination of the disparate worldwide mission-operations elements. In addition to spacecraft operations, nominal to any space mission, overall mission operations include a large ground operations component specific to SVLBI missions. This includes very wideband data acquisition and very high-precision frequency/time synchronization and orbit determination/navigation provided by a specialized network of five 10to 14-m ground tracking stations around the world and the co-observing support of up to 40 ground radio telescopes around the world. The NASA Deep Space Network (DSN) and the U.S. Space Very Long Baseline Interferometry (VLBI) Project (U.S. SVLBI Project) at JPL are responsible for mission operations support with three of the five ground tracking stations and for co-observing support with the DSN 70-m ground radio telescopes. This article will describe the overall SVLBI mission operations system with particular attention to the mission elements provided by the DSN. The requirements for support of future missions and necessary improvements to increase the efficiency of mission operations and to decrease mission operations costs also will be described.