System Testbed Use on a Mature Deep Space Mission: Cassini

The Cassini-Huygens Program is a joint effort between the European Space Agency (ESA), which delivered the Huygens probe, and the National Aeronautics and Space Administration (NASA), which delivered the Cassini spacecraft. The Jet Propulsion Laboratory (JPL) manages the Cassini spacecraft for NASA. Cassini's primary mission is to survey the complex Saturnian system and release the ESA-Huygens probe at Titan. The Cassini Integrated Test Lab (ITL) at JPL is a high-fidelity hardware-in-the-loop testbed. It uses Attitude and Articulation Control Subsystem (AACS) and Command and Data Subsystem (CDS) flight hardware (H/W), as well as high-fidelity simulations of the other spacecraft subsystems and signals. System Testbeds like the Cassini ITL are often considered to be primarily used in the Final Design and Fabrication Phase and the System Assembly, Integration & Test and Launch Phase of a Mission, but the Cassini ITL has proven to be an essential component of an extremely successful Operations and Sustainment Phase. This paper discusses the role of the Cassini ITL since Cassini's launch, through cruise, orbit insertion at Saturn, probe release at Titan and throughout its tour as Cassini enters the final year of its primary mission.