The MMS Burst System; Co-operative concept of flight-ground operations to maximize burst system science data return

The Magnetospheric MultiScale (MMS) mission is a 2 year mission that will study reconnection in the Earth's magnetosphere. The four MMS observatories will be required to fly in a tetrahedral formation in order to unambiguously determine the orientation of the magnetic reconnection layer. At highest resolution, the Instrument Suite (IS) on each MMS spacecraft will produce scientific measurements many times faster than the orbit-averaged telemetry rate. Although high-resolution measurements are essential to understanding magnetic reconnection, these measurements are needed on the ground for only a fraction of the orbit. Within the MMS system, the flight Burst System is designed to store the high- resolution data for the full time during the period of the orbit, called the Region of Interest (ROI), that is the most likely to contain the magnetic reconnection events. Then, the ground portion of the Burst System is designed to select snippets (typically one to five minutes in duration) of the high resolution data that are most likely to contain a reconnection event. On the MMS mission, to determine when a reconnection event may have occurred, it is necessary to correlate data from all four MMS observatories. Avoiding the complexity of having four observatories communicating every 10 seconds within a 12 or 36 hour ROI was a primary driver to the creation of a shared flight-ground responsibility for the Burst Data selection activity. This paper outlines the key flight and ground segment elements that are being implemented to support this co-operative flight-ground operations approach to the Burst Data selection process, as well as outlining some of the primary challenges associated with this flight-ground split of responsibilities.