The [PowerPC] 603e processors also power all 66 satellites in the Iridium satellite phone fleet. The satellites each contain seven Motorola/Freescale PowerPC 603e processors running at roughly 200 MHz each.[1]

There is a radiation hardened version called "RHPPC" based on PowerPC 603e made by Honeywell & Freescale. RHPPC is equivalent to the commercial PowerPC 603e processor with the minor exceptions of the phase locked loop (PLL) and the processor version register (PVR). [2]

[1] http://en.wikipedia.org/wiki/PowerPC_600#PowerPC_603e_and_60...

[2] http://en.wikipedia.org/wiki/RHPPC