Joint Cognitive Systems

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Chapter 8

Anomaly Response

Cascading Effects in an Episode of Anomaly Response

Several minutes into the ascent phase of a space shuttle mission (Figure 7 ),

one of the flight controllers r esponsible for monitoring the health and safety of the

mechanical systems in mission control centre noticed an anomaly – an unexpected

drop in hydraulic fluid in an auxiliary power unit (APU). The personnel

monitoring immedi ately recognized that the anomalous reading pointed to a

hydraulic leak. Did this anomaly require an immediat e abort of the ascent? In

other words, she n eeded to assess—How bad w as the leak? Was it a threat to the

safety of the mission? What were the relevant criteria (and who knew them, and

where did they reside)? The mechanical systems