Procedure Devolvement over Time in a Seriesed Spacecraft Program

National Oceanic and Atmospheric Administration (NOAA) N-Prime is one of a series of satellites built by the Goddard Space Flight Center (GSFC) and uses handling procedures originally developed at the program’s outset. The spacecraft has a deploy-able Search and Rescue Antenna (SRA) which was originally “hard stowed” using a non-flight bolt and T-nut in the baselined procedure. The procedure was progressively modified and devolved over time due to the changing GSE availability and allowed for using a lance cord in lieu of the hard stow to secure the antenna in a “soft stow”. During ground operations the spacecraft was rotated and the SRA inadvertently deployed when the cord broke. The SRA broke through a hard stop bracket and damaged an instrument optical sensor radiator panel. The satellite damage was minimal and there were no injuries to personnel. A Mishap Investigation Board (MIB) was commissioned to investigate this mishap. Their findings form the basis for this lesson.

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