In the early nineteenth century, scientists assumed that the Sun worked just like any fire on Earth, that there was a source of fuel, perhaps coal, that was slowly burning away.
But other suns, stars as the astronomers call them, are bound to have planets like our own, and as is the number of stars in the universe is so vast, this possibility becomes virtual certainty.
The spacecraft will have to deal with extreme heat and radiation levels as it moves closer to the surface. However, the probe is expected to make observations that will add to scientists' understanding of the Sun.