Magellan’s expertise in command and data handling (C&DH) subsystems traces back to the Hermes/CTS mission in the 1970s and includes over 120 Black Brant sounding rocket flights, as well as Space Shuttle and International Space Station (ISS) experiments. Today’s Magellan C&DH is a compact PCI-based system with a suite of peripheral cards (processor, data handling, power supply, input/output) that receives commands from the communication subsystems, performs command decoding and validation, and distributes commands to the appropriate subsystems and payloads. It also receives and packages engineering telemetry and science data from subsystems and payloads. The baseline product has a dual-string architecture consisting of an operational unit and a cold spare. If a fault should occur, the C&DH unit manager will initiate an autonomous non-recursive switchover to the redundant string.