Enabling technologies for ice giant exploration.

Future missions to an ice giant planet, especially orbital missions, are technologically challenging. But with one exception, radioisotope power sources (RPSs), the technologies that would enable such missions are currently available. RPSs are not a new technology, but devices used in the past that are appropriate to an ice giant mission are no longer available without engineering development work (currently unfunded), and it is uncertain whether the new NASA unit under development will be available for flight in time to take advantage of the best transfer trajectories of the next 15 years. This paper describes technologies already in hand that enable an ice giant mission, but for them to be useful they must be maintained. If an enabling technology is lost a replacement must be developed, potentially impacting the cost and schedule of a mission. In addition to the enabling technologies, there are a number of technologies that, while not enabling, could greatly enhance the science return and science value of a mission, making the programmatic aspects of approval an easier task and the funding of those development tasks a high priority. This article is part of a discussion meeting issue 'Future exploration of ice giant systems'.