Managing the Risk of Command File Errors

Abstract

Command File Error (CFE), as defined by the Jet Propulsion Laboratory's (JPL) Mission Operations Assurance (MOA) is, regardless of the consequence on the spacecraft, either: an error in a command file sent to the spacecraft, an error in the process for developing and delivering a command file to the spacecraft, or the omission of a command file that should have been sent to the spacecraft. The risk consequence of a CFE can be mission ending and thus a concern to space exploration projects during their mission operations. A CFE during space mission operations is often the symptom of some kind of imbalance or inadequacy within the system that comprises the hardware & software used for command generation and the human experts involved in this endeavour. As we move into an era of enhanced collaboration with other NASA centers and commercial partners, these systems become more and more complex and hence it is all the more important to formally model and analyze CFEs in order to manage the risk of CFEs. Here we will provide a summary of the ongoing efforts at JPL in this area and also explain some more recent developments in the area of developing quantitative models for the purpose of managing CFE's.

Modeling to Improve the Risk Reduction Process for Command File Errors

“…The second, a Bayesian Belief Network (BBN) captures the different types and causes of CFEs. Initial results and findings from this model development approach were reported at the Aerospace Sciences Meeting (ASM) 2013 in "Managing the Risk of Command File Errors" [1]. As articulated in the paper, the authors came to this conclusion:…”

“…Therefore they are amenable to probabilistic modeling and analysis techniques. A brief overview of the types of probabilistic analysis techniques we have used for this purpose was presented in [1]. In this paper, we demonstrate the application of these techniques to a specific flight project and present the numerical results from those studies.…”

Addressing the hard factors for Command File Errors by Probabilistic Reasoning

“…We broadly categorize the root causes for a CFE as soft factors or hard factors [1]. Soft factors are those that mainly contribute to the operator cognition, for instance the level of training, situational awareness or management and organizational factors.…”