Hi; for some of those questions I'll direct you to the FAQ, but regarding the last question -- there is a NASA mission being planned to send a probe very close to the sun, and in fact through the corona. This is incredibly difficult, since the instruments and craft have to endure launch, deep space, and then the high-radiation high-temperature regime of the solar corona, AND have instruments functioning during some of the worst parts of the trip. It's an engineering challenge. The mission is called Solar Probe, and you can read about it more at http://solarprobe.gsfc.nasa.gov/. -KD