> Also, RTGs are big and heavy From what I gathered that was actually a major reason, considering that the plan was to land the probe unharmed on the comet. Mo

> Also, RTGs are big and heavy From what I gathered that was actually a major reason, considering that the plan was to land the probe unharmed on the comet. More weight for power generation would likely have meant more weight to make whatever is involved in landing stronger and ultimately probably less weight dedicated to instruments.