The space glass has a composition, in wt. % based on oxide content, of: SiO2, 5-65; B2O3, 0-40; Al2O3, 0-12; PbO, 25-50; Na2O 0-8; K2O, 0-20; Σ alkali metal oxides, at least 0.25; and at least 0.1 wt. % of a total amount of three or more doping agents selected from CeO2, MoO3, Bi2O3, WO3, Ag2O, SnO2, Sb2O3 and As2O3. In addition, it contains one or more of the following doping agents in the following amounts: at most 1 wt. %, CeO2; at most 0.02 wt. %, As2O3; at most 0.3 wt. %, Sb2O3; and at most 0.5 wt. %, SnO2. Light-weight optical systems for space are made from it, because of its high radiation resistance. A preferred process for making space glass includes melting the oxide starting ingredients at 1050° C. to 1200° C. to form a melt and refining the melt at 1230° C. to 1350° C.