Recently, radiation-hardened SRAM-based field programmable gate arrays (FPGAs), anti-fuse FPGAs, and radiation-hardened flash-based FPGAs have been used frequently for space systems. The total-ionizing-dose tolerances of such radiation-hardened FPGAs are limited to a 1 Mrad total ionizing dose. However, if the total-ionizing-dose tolerance of the embedded systems could be increased, a shield-less space embedded system could be realized, drastically decreasing rocket launch costs. This paper therefore presents a proposal of a new, radiation-hardened optically reconfigurable gate array very large scale integration (VLSI) exploiting its parallel configuration. The total-ionizing-dose tolerance of the radiation-hardened optically reconfigurable gate array has been measured experimentally as a 603 Mrad total-ionizing-dose using a Cobalt 60 gamma radiation source, which has at least 603 times higher radiation tolerance than those of currently available radiation-hardened FPGAs.