Rendering of an Iridium Next satellite. The constellation’s first launch is scheduled for June 2015. Photo: Iridium

[Via Satellite 09-24-2014] Iridium has finished testing a new solar panel design for use on the Iridium NEXT constellation. Built by Spectrolab and Mitsubishi Electric, the improved triple junction solar cells are based on six-inch wafers, providing 50 percent more solar cell surface area than those on Iridium’s current satellites.

At full extension, the solar panels measure 9.4 meters and can generate more than 2 kW of power. The testing subjected the cells to 75,000 thermal cycles to simulate the charging environment in Low Earth Orbit (LEO). Iridium’s solar panels were tested to 1.5 times the expected lifetime of the satellites to promote constellation longevity. The design verification test also evaluated all potential mechanical and electrical configurations.

Iridium plans to have 66 in-orbit satellites in its next-generation constellation, along with several in-orbit spares. Launches begin in 2015 with full deployment expected by 2017. Thales Alenia Space is the prime contractor for Iridium NEXT.