The Parker Solar Probe flies through the sun's outer atmosphere behind a carbon shield eleven and a half centimetres thick, and the arrangement works so well that while the front face glows at almost fourteen hundred degrees, the instruments sitting a metre - Space Daily

Parker Solar Probe is designed to do something few spacecraft could attempt: fly through the Sun’s outer atmosphere and keep working. At its closest approaches, it passes about 6.2 million kilometres above the Sun’s visible surface, where sunlight is hundreds of times more intense than it is at Earth.

Its survival depends on a carbon shield that is just 11.5 centimetres thick but highly effective. The Sun-facing side can glow at nearly 1,400 degrees, absorbing the extreme heat while the rest of the spacecraft remains protected behind it.

That protection creates a striking temperature difference. Instruments positioned roughly a metre behind the shield stay cool enough to operate, despite the fierce conditions on the front of the probe. The arrangement shows how the spacecraft separates its most delicate systems from the harsh environment outside.

This thermal design is what allows Parker Solar Probe to work so close to the Sun. By enduring the intense radiation and heat in that region, the mission can study the Sun’s outer atmosphere from a far closer vantage point than missions operating near Earth.