The original Iridium satellites had large metal panels (which contained the phased array antennae) that were at a bit of an angle to the ground, this made it po

The original Iridium satellites had large metal panels (which contained the phased array antennae) that were at a bit of an angle to the ground, this made it possible for reflected sunlight to hit the Earth, causing a "flare" for whoever happened to be in that beam. The Iridium NEXT satellites have an antenna panel that is much closer to parallel to the surface of the Earth, so any reflected sunlight beams will pass at a glancing angle and won't intersect the Earth.