In the old days, spacecraft alarming notifications to operators were directed, upon arrival to ground, to one of those needle printers. Trained operators could tell, from the length and rhythm of the printer noise, what kind of alarm it was and therefore infer the criticality or the subject. Today, in monitoring and control systems (MCS) currently in use at the European Space Agency (ESA), there is no care to convey information in the sounds, and these alarm sounds have not been systematically designed to indicate the type of system failure and further elicit the desired and accurate operator response. Operators depend heavily on the graphical interfaces in order to pinpoint the source of alarm sounds (see Fig. 1) which further creates cognitive load. Similarly, switching cost from auditory perception to visual perception while finding the source of the information is undesirable when time can be a precious commodity for operators when monitoring valuable spacecraft. Therefore, ESA teamed up with Delft University of Technology and Plymouth University in order to investigate and design a new auditory display for the control rooms located in the European Space Operations Centre (ESOC), in Darmstadt, Germany

Satellite monitoring and control systems provide the possibility for audible alarms to signal system events that require operators to pay attention and eventually to take action. The audible alarms that are currently in use at ESA control areas are very basic and unfortunately non-discriminating with respect to the events they are signalling. These audible alarms consist of sound files often arbitrarily fished out from the Internet; thus, when they sound they convey no added information about the event that caused it. No considerations whatsoever are made concerning their suitability, ergonomic aspects, or effects of such alarms on operators working on long shifts. Because sounds are prompting a much faster reaction from operators than visual cues, when used efficiently they can also be made to establish criticality, urgency, origin or expected action (think for example on your car alarm that tells you to buckle up or that you are about to bump the car behind you). This paper describes the work performed together with Delft University of Technology and the University of Plymouth to analyse the satellite monitoring problem, to define a sound alarm philosophy that foresees different levels of urgency/criticality associated with typical operator actions based on contextual enquiry in the field, and the corresponding implementation of a library of coherent sounds that include 3 themes of 5 sounds each that map to the levels defined. It will also describe the evaluation of the sounds with operators and how the Cluster mission is implementing a solution to deploy this alarm philosophy and sounds in its dedicated control area, making sure to analyse evolution of operator behaviour before and after the deployment.