During final assembly of the Orion spacecraft at Kennedy Space Center in Florida, engineers identified an issue with a redundant channel on one of the spacecraft’s Power and Data Unit (PDU) communication cards. Orion has a total of eight PDUs, each of which has two cards with two redundant channels on each card that help provide communication between Orion’s flight computers to its components.
As a spacecraft designed to carry humans to deep space, Orion is built with significantly more redundancy to protect against failures than a robotic spacecraft. The PDU is still fully functional and will use its primary channel during the Artemis I mission, which is a non-crewed test flight.
During their troubleshooting, engineers evaluated the option to “use as is” with the high-degree of available redundancy or remove and replace the box. They determined that due to the limited accessibility to this particular box, the degree of intrusiveness to the overall spacecraft systems, and other factors, the risk of collateral damage outweighed the risk associated with the loss of one leg of redundancy in a highly redundant system. Therefore, NASA has made the decision to proceed with vehicle processing.
NASA has confidence in the health of the overall power and data system, which has been through thousands of hours of powered operations and testing. Engineers will perform additional testing and continue to monitor the health of the spacecraft while Orion is powered on to provide continued confidence in the system.
NASA will proceed with spacecraft processing, and engineers are currently completing final closeout activities and will transfer the spacecraft in mid-January from the Neil Armstrong Operations and Checkout Facility to the Multi-Payload Processing Facility for fueling and preparation for integration with the Space Launch System rocket. The new timeline does not impact the launch schedule, and NASA remains on track for a launch in November 2021.
Check back at this blog for more updates as Orion prepares for its transition from assembly to launch operations.