Spacecraft require electrical energy. This energy must be available in the outer reaches of the solar system where sunlight is very faint. It must be available through lunar nights that last for 14 days, through long periods of dark and cold at the higher latitudes on Mars, and in high-radiation fields such as those around Jupiter. Radioisotope power systems (RPSs) are the only available power source that can operate unconstrained in these environments for the long periods of time needed to accomplish many missions, and plutonium-238 (238Pu) is the only practical isotope for fueling them. Plutonium-238 does not occur in nature. The committee does not believe that there is any additional 238Pu (or any operational 238Pu production facilities) available anywhere in the world.The total amount of 238Pu available for NASA is fixed, and essentially all of it is already dedicated to support several pending missions-the Mars Science Laboratory, Discovery 12, the Outer Planets Flagship 1 (OPF 1), and (perhaps) a small number of additional missions with a very small demand for 238Pu. If the status quo persists, the United States will not be able to provide RPSs for any subsequent missions.

This report explores the main reasons behind the unreliable supply of Technetium-99m (Tc-99m) in health-care systems and policy options to address the issue. Tc-99m is used in 85% of nuclear medicine diagnostic scans performed worldwide – around 30 million patient examinations every year. These scans allow diagnoses of diseases in many parts of the human body, including the skeleton, heart and circulatory system, and the brain. Medical isotopes are subject to radioactive decay and have to be delivered just-in-time through a complex supply chain. However, ageing production facilities and a lack of investment have made the supply of Tc-99m unreliable. This report analyses the use and substitutability of Tc-99m in health care, health-care provider payment mechanisms for scans, and the structure of the supply chain. It concludes that the main reasons for unreliable supply are that production is not economically viable and that the structure of the supply chain prevents producers from charging prices that reflect the full costs of production and supply.

Contributing Authors Include P. C. Aebersold, J. R. Bradford, G. D. Calkins, And Many Others.