Via the Guardian:

The US is to fly a spy plane over the stricken Fukushima plant in a bid to get a closer look at the damage, according to Kyodo news.
The Japanese news agency said the military will operate an unmanned Global Hawk high-altitude reconnaissance aircraft over the plant, perhaps as soon as Thursday, to examine the plant’s reactors, Kyodo said, quoting a government source.
“Photographs taken by the plane equipped with infrared sensors could provide a useful clue to what is occurring inside the reactor buildings, around which high-level radiation has been detected,” it added.

This comes after Japanese helicopters were unable to dump water onto the Fukushima reactors due to the high radiation level.