The main barrier that holds us back from exploring the sun closely is the Amount of heat present on it's surface (6000 degrees appx.). Now we know that on the surface of the sun are black non luminous spots created due to helium. If we could build a space craft, having vacuum circulation of a noble gas such as helium, then we could actually go really close to the surface of the sun right? It's simple, its exactly the principle used by Edison to prolong the life of an electric bulb! Comments please!