The aerial water bombardment of Japan's Fukushima Daiichi nuclear facilities began in earnest late yesterday after being deemed too risky earlier in the week. The strategy--previously untested as far as we know--is aimed at cooling the reactor cores and spent fuel rod storage pools, but it's highly unclear whether it's doing any good. The choppers are dropping their payloads on the go, presumably out of radiation fears, and as such Japanese authorities can't ascertain whether any of the water has actually been delivered to its targets.
That means the UAV can gather imagery showing where the hot spots are, what parts of the reactors may be closest to rupture or other damage, whether or not fires have been completely extinguished, and, over time, the effectiveness of different methods of cooling.
At this point, those methods are diverse. The remaining workers on the ground are braving elevated radiation levels to direct fire hoses at the various overheating elements within the complex, and that previously-scrubbed strategy to drop water from above via firefighting helicopter has now been initiated as the situation becomes more desperate. The effectiveness of the water-bombing at this point is unknown, though it doesn’t appear to be doing much good. May we recommend a bigger bomber?