A blend of americium and curium fuel-cycle discharge products is assessed for its applicability to radioisotope heat-source production for future space and terrestrial radioisotope heat and power systems. Separation techniques such as the selective actinide-extraction process are evaluated and an estimate of the mixed source specific heat output power is made. The effective half-life (T1=2) of the composite isotope heat source was determined to be 35.3 years and the specific thermal output power of the metallic composite source was estimated to be 0:347 W=g.