The mechanism providing the flare/glint are the
Main Mission Antenna (MMA) on each of the satellites. These antennas (of which there are three- 120 degrees apart, 188 cm wide x 86 cm long x 4 cm thick each) are highly reflective aluminum flat plates (treated with silver-coated Teflon for thermal control) that are angled 40 degrees away from the axis of the body of the satellite.
Here are detailed viewsof the satellite taken at the NASM. Daniel Deakalso provides photos taken at the NASM.
The axis of the satellite body is maintained vertical to the Earth's surface. It is the maintenance of the operational satellite's axial and longitudinal position that allows the flares to be predicted.
On November 15, 2000 it was announced that
Iridium Satellite LLCwill take over the assets of Iridium LLC and maintain the constellation in orbit. Details of the purchase can be found at
SpaceFlightNow.Com.
On December 12, 2000, Iridium Satellite LLC announced additional satellite launches for 7 more satellites. Tentatively planned was a launch in late 2001 by a Delta II with five satellites. The launch date was later moved to early 2002. There is also a Russian launch tentatively planned in June 2002 with two satellites. The goal is to maintain 6 orbital planes with 11 operable satellites per plane along with two or more spares per plane.
The plate or MMA can provide a direct (specular) reflection of the sun's disk. This specular reflection is only tens of kilometers wide at the Earth's surface. In order to see a very bright reflection, the observer must be within this relatively small area.
Prediction programsare available to determine this area.
The three sided (similar to an equilateral triangle)
satellites themselves are not very large, approximately 4 meters long and less than one meter in width.
Alan Rohwer, a SeeSat-L subscriber, provided the initial construction details and provides
additional information on the construction of the satellite which may account for unexplained reflections not predicted by the flaring prediction programs.