Thus scientists have been eager for a mission to the sun since space travel first became possible. But the extreme temperatures meant they needed to wait until the development of technology that could shield the spacecraft from the intense heat and radiation of the sun. The Parker Solar Probe’s heat shield, made of just under five inches of a cutting-edge carbon composite, will keep the craft’s delicate instruments at a gentle 85 degrees Fahrenheit even as the corona rages at 3 million degrees Fahrenheit outside.It will need it, because when the spacecraft launches in August, it will begin a seven-year journey to the blisteringly hot corona, visible as the halo around the sun during an eclipse. It will be by far the closest we’ve ever come to a star, and scientists are itching to get a look at the physics close-up.
Two of the most pressing questions for this mission, which date back to Parker’s earliest work: Why is the corona so much hotter than the surface of the sun? How does the solar wind accelerate away from the sun?
A deeper understanding of these processes will help forecast space weather that affects life here on Earth, understand the conditions that astronauts in orbit above our world and journeying for long distances would face, and even provide clues about what kinds of star activity might favor habitability on distant planets.