A deep-space exploration probe is powered by a Radioisotope Thermoelectric Generator (RTG) containing plutonium-238.
At the launch of the mission, the RTG is loaded with 3.20 kg of plutonium-238.
The thermal power density of pure plutonium-238 is 0.55 W g-1.
Plutonium-238 has a half-life of 87.7 years87.7\text{ years}87.7 years.
Calculate the rate of heat energy released by the RTG (in watts) after a duration of 263.1 years263.1\text{ years}263.1 years.