Russia [1] (B.A. Briskman, V.I. Toupikov, E.N. Lesnovsky, Proceedings of the Seventh International Symposium on Materials in Space Environment, Toulouse, France, 16–20 June 1997, ESA, SP-399, p. 537) has proposed new international standard for the testing of materials to simulated space radiation. The proposal was submitted to ISO (The International Organization for Standards) Technical Committee 20 (Aircraft and Space Vehicles), Subcommittee 14 (Space Systems and Operations) and was approved as Working Draft 15856 at the Los-Angeles meeting (1997). The second version of the draft was approved at the Beijing meeting (1998). The standard extends to space ionizing radiation: protons, electrons, solar ultraviolet, soft X-radiation, bremsstrahlung, that effect the polymeric materials of space engineering. The special feature of interaction of the space ionizing radiation with materials is the localization of the main part of absorbed energy in thin near-surface layers. Numerous problems appear in simulating the ionizing radiation impact, which require a solution for correct conduction of the on-ground tests.