An interplanetary probe requires a continuous electrical power of 2.0 kW for 180 days. It will use a deuterium–tritium fusion unit working at 35% efficiency in converting nuclear energy to electricity (energy per fusion event = 17.6 MeV).
(i) Determine the total number of fusion events needed for the mission.
(ii) Calculate the total mass of deuterium and tritium consumed, assuming each event involves one deuterium nucleus of mass 2.0u and one tritium nucleus of mass 3.0u. (Take 1u=1.66×10−27kg and 1eV=1.6×10−19J.)