Data Handling Subsystem

The Data Handling Subsystem (DHS) provides all telemetry acquisition and processing, and forwards telemetry to the Telemetry ,Tracking and Command Subsystem (TTC) for transmission to Earth. When the spacecraft is not being tracked, data is stored on one of two redundant 45 Mbit tape recorders or Data Storage Units (DSUs) on board for later transmission.

The DHS also acquires, decodes, and accepts incoming commands from the TTC subsystem and distributes these commands to the instruments and platform subsystems. Forty commands can also be stored in the spacecraft time-tag buffer for later timed execution when necessary.


The DHS incorporates a microprocessor system with a special purpose software package designed for Ulysses. Software applications monitor spacecraft health and safety, initiate recovery and reconfiguration, and carry out on-board data processing. A variety of timing signals are also distributed for use by the other subsystems and the science instruments.