Magneto-resistive Random Access Memories (MRAMs) are of interest for space and radiation-hardened electronics applications, based on solid-state form factor, non-volatility, radiation hardness, modularity, reliability, scalability, fault tolerance, support for mission assurance, small size, low mass, and low power consumption. MRAMs provide higher bit storage densities and other advantages with respect to preceding space-qualified non-volatile magnetic solid-state memory technologies, such as magnetic plated wire memories and magnetic core memories. Honeywell has QML-qualified 16Mb single-chip package (SCP) and 64Mb multi-chip module (MCM) toggle MRAM products; and is developing products to scale towards and then beyond gigabit SCP and gigabyte MCM STT-MRAMs to offer long life (>15 years), unlimited write and read endurance (>10(15) cycles), unlimited data retention (>15 years), non-destructive readback, fast write and read cycle times (<50 ns), radiation hardness (>1Mrad(Si)), and low error rates (<10(-10) errors/bit/day at geosynchronous orbit at solar minimum with 100 mils of Al shielding) across a broad temperature range (-40 degrees C to +125 degrees C).