The surface of the Sun is 10,000 Fahrenheit, but its outer atmosphere—the corona—is way hotter, about 3.5 million Fahrenheit. Its blistering heat is the reason why no spacecraft has been able to go anywhere it.
But in July 2018, NASA will send a piece of hardware to reconnaissance it from close quarters. The Parker Solar Probe will get within four million miles of it with the gravitational assist of seven Venus flybys and make 24 orbits of our parent star.
It’ll be protected by a shield made from a carbon-carbon composite, which will keep its instruments safe in the range of 70 Fahrenheit.