Taking the APL Mini-MOC Concept to the Next Level (Down)

Abstract

In late January of 2007, the Electronic Systems Group of the Johns Hopkins University Applied Physics Laboratory’s (JHU/APL) Space Department was tasked with the development and verification of the Power Distribution Units (PDU) for the National Aeronautics and Space Administration’s (NASA) two Radiation Belt Storm Probe (RBSP) spacecraft. The PDU was a new design, single string (no redundancy) and resided on the critical path of the spacecraft Integration and Test (I&T) schedule. Due to these factors, newly designed test sets were required to be developed (on an aggressive schedule) that would offer the individual board designers and the box level testers a reliable, repeatable, autonomous, and user-friendly platform with which to work. JHU/APL has been successfully utilizing the concept of Mini-MOCs (Mini Missions Operation Centers) to perform subsystem (box) level testing for more than a decade on multiple missions. These Mini-MOCs typically utilize a Commercial-off-the-Shelf Command and Telemetry (COTS C&T) product along with JHU/APL-developed software to provide a subset of full MOC capabilities. The PDU Test Team made the decision to attempt to bring the Mini-MOC concept down to the individual slice (circuit board) level to test all three types of PDU slices before attempting to integrate the slices together. This enabled the PDU Test Team to utilize the repeatability, autonomy, and user friendly aspects of the COTS C&T to meet all of the test set requirements, along with streamlining the box-level testing schedule. In this paper, the PDU Test Team describes the engineering process undertaken to accomplish this task along with some lessons learned along the way.