Atmel Introduces the AT697F Radiation-Hardened SPARC V8 Processor for Space Missions.
Joerg explains on why SPARC?:
"The reason is not Solaris. It´s a different one. Despite general opinion, SPARC isn´t a proprietary architecture. You get go to SPARC International, get the specification for a 100 bucks or so and you can develop and manufacture your own SPARC CPU. This was used by the European Space Agency to develop a radiation hardened version of a SPARC architecture. The development is called LEON, the proc named in the article uses the LEON2-FT design. The LEON2 and LEON3 design are available under the GNU General Public License respectively under the GNU Lesser General Public License. Being able to get such an architecture essentially for cheap money was the essential reason behind the decision for SPARC (besides of other technical reasons)"