sun

There is a reason they tell you "don't look directly at the eclipse." This is it.

Yahoo Answers: Why NASA Not Gone to The Sun

The poster on Yahoo Answer goes on to suggest that if they went in the winter, then they could avoid the heat that is typically associated with such long journeys. A fellow poster provides and even better solution of limiting the NASA missions to the sun to only be at night. With such a rich bastion of brain power on Yahoo Answers, it is a bit surprising that they have not solved more of the worlds problems.