Reach in ecliptic longitude around transit for the leading side of the survey, for SAA ∈ [87°, 104°]. Shown in red is the reach for the originally planned symmetric AA range. To minimise the stray light in VIS, the range was shifted to AA ∈ [$-8_{\cdot }^{\circ }4,-3_{\cdot }^{\circ }0$] with much reduced visibility (grey) that would not permit the completion of the survey. By allowing the fields to rotate by up to 3° with respect to the tessellation, a much larger area of the sky becomes accessible (blue). For observations in the trailing side, the areas must be rotated by 180° around the origin.