NASA’s Parker Solar Probe Will Aim to "Touch the Sun": Everything We Know

In a mission that sounds inspired by the myth of Icarus, NASA’s Parker Solar Probe is expected to become the first spacecraft to enter the sun’s corona, or outer atmosphere. Although this daredevil mission has been delayed, the probe now includes an innovative new heat shield that will hopefully improve its odds.

On August 4, Parker Solar Probe will embark on what NASA calls “a mission 60 years in the making,” coming within four million miles of the surface to collect unprecedented data about the sun’s corona. Temperatures for expected to reach nearly 2,500 degrees Fahrenheit at the probe’s upcoming destination, but if the new heat shield is a success, the instruments inside the spacecraft will enjoy a balmy inside temperature of just 85 degrees.

The new and improved heat shield, known as the Thermal Protection System, is made of a lightweight carbon foam core that is flanked by two carbon-carbon composite panels. The sun-facing panel is sprayed with a white coating that will reflect as much of the sun’s energy away from the spacecraft as possible. While the Thermal Protection System was once attached to Parker Solar Probe during testing in 2017, this is the first time the heat shield has been fully integrated with the spacecraft.

The mission is expected to achieve many firsts, traveling nearly seven times closer to the sun than any previous spacecraft. Once launched, Parker Solar Probe will charge towards the sun at over 430,000 miles per hour, making it the fastest man-made object in the solar system. To understand that speed in context, that’s fast enough to travel from Philadelphia to Washington, D.C. in one second, leaving Elon Musk’s wildest dreams for a Hyperloop in the dust.

After launching on August 4, Parker Solar Probe will use Venus’ gravitational pull to shrink its orbit around the sun. These flybys will take roughly seven years, eventually bringing the probe as close as 3.7 million miles from the center of the solar system. Its final loop within the sun’s corona is expected in late 2024.

As part of NASA’s Living with a Star Program, Parker Solar Probe is meant to explore aspects of the sun that directly affect life and society. The results of this mission not only have the potential to improve scientists’ understanding of the sun’s atmosphere, but could mark a historic milestone in society’s longstanding pursuit of Helios.