What are the ramifications of MPS visibility ratios >5%?
If the ratio of ratio of proposed eclipses to viable eclipses for an observation rises above 5%, then the uncertainty in meeting the proposed total exposure time increases (FAQ 107). This is not to say that the proposal is not possible but it becomes increasingly difficult to include such proposals in a mission plan that has to accommodate the successful completion of other plans (GI and PI). No definite answer can be given during the technical review to any scheduling question, except for the rejection of plans that propose for more eclipses (visits) than are viable for that observation in the during the period of that GI cycle. The 5% threshold is based on prior experience of the mission planning team, including uncertainty in losses due to detector shutdowns and data transmission dropouts. Eclipses that are lost due to unforeseen circumstances may result in observations not being observed at all during the GI cycle if there is only a narrow range of viable eclipses. Visibility ratio
