NASA Radioisotope Power Systems Program Next-Generation RTG Study: Summary 2017

The Next-Generation RTG study recommends a modular configuration packaged as up to eight variants that would be sized to house between two and 16 GPHS modules as the RTGs heat source. The largest of these concepts would produce at least 400 watts of electricity, would degrade at only ~1.9 percent per year (leading to signicantly higher end-of-mission power), and would weigh less than
132 pounds (60 kilograms).