Farewell, Europa.

“The ASRG program was created to help extend the life of the remaining Pu-238 supply. It uses a Stirling engine to generate electricity at four times the efficiency of a regular RTG. This means more missions to these harsh places using less Plutonium. While NASA has started to generate Pu-238 again, it won’t be ready to use until 2019, and even then the Department of Energy will only produce about 1kg – 1.5kg per year. The New Horizons mission to Pluto used about 11kg, which would take anywhere from 7 – 11 years to generate under the current plan.”

Because of sequestration and other budget cuts, NASA is forced to cancel its advanced spacecraft power program, threatening future missions past the asteroid belt. “ASRGs had been under development by NASA for over a decade, and had been planned for use by 2016 in the next low-cost planetary exploration missions…Because of the limited cost cap imposed on these missions, they’re now essentially limited to the inner solar system. Missions with bigger budgets that could afford regular RTGs will be bottlenecked by the production rate of Plutonium to maybe once or twice per decade. Goodbye, outer planets.”