The sun, the very centerpiece of our solar system and the most important source of energy for life on Earth, is on the verge of receiving a visitor.
In the summer of 2018, NASA will launch its Parker Solar Probe, a spacecraft with the unprecedented mission of traversing nearly 93 million miles to study some of the sun's biggest secrets. It's named after astrophysicist Eugene Parker, the S. Chandrasekhar Distinguished Service Professor Emeritus in the Department of Astronomy and Astrophysics at the University of Chicago, who discovered the phenomenon now known as solar wind.
“The solar probe is going to a region of space that has never been explored before,” said Parker in a statement. “It’s very exciting that we’ll finally get a look. One would like to have some more detailed measurements of what’s going on in the solar wind. I’m sure that there will be some surprises. There always are.”
“Placed in orbit within 4 million miles of the sun’s surface, and facing heat and radiation unlike any spacecraft in history, the spacecraft will explore the sun’s outer atmosphere and make critical observations that will answer decades-old questions about the physics of how stars work,” NASA said in a statement. “The resulting data will improve forecasts of major space weather events that impact life on Earth, as well as satellites and astronauts in space.”
Unlike the Greek legend Icarus, whose wings melted when he flew too close to the sun, NASA's new spacecraft will come prepared. To protect its instruments from temperatures approaching 2,600 degrees Fahrenheit, the Parker Solar Probe (which was originally named the Solar Probe Plus) features an 8-foot-wide, 4.5-inch-thick carbon-composite foam shield.
Unlike traditional armor, the solar shield weighs only 160 pounds and, according to Vice, has an internal structure of 97 percent air. The engineering behind its design is so efficient that those components protected on the shaded side will astoundingly experience nothing more than room temperature.
Much like the Cassini spacecraft's series of ever-closer dives toward Saturn, the probe will experience no fewer than 24 close encounters with the sun using repeated gravity assists from Venus. Its most precarious dive through the sun's outer atmosphere, projected to occur in 2024, will have it passing by the sun's surface at a distance of only 3.8 million miles. As a comparison, the closest NASA has ever approached the sun is from a distance of 27 million miles with the Helios 2 spacecraft in 1976.
At that point, the Parker Solar Probe will make history by becoming the fastest man-made object ever. Its closest approach to the sun will send the spacecraft speeding along at a record-breaking 450,000 miles per hour. “That's fast enough to get from Philadelphia to Washington, D.C., in one second,” NASA added.
Exposing the sun's secrets
In addition to sending a spacecraft into uncharted, scorching territory above a star, NASA also has a series of scientific objectives to accomplish. These include a study of the causes behind the sun's wildly different temperatures (i.e., an atmospheric temperature range of 3.5 million F vs. a surface temperature of "only" 10,000 degrees F) and the forces behind its solar wind and energetic particles that impact Earth and the solar system.
"There are a few major mysteries with the sun and the solar wind," SPP project scientist Nicola Fox told Vice. "One is that the corona — the atmosphere that you see around the Sun during a solar eclipse — is actually hotter than the surface of the sun. So, that kind of defies the laws of physics. It just shouldn't happen."
NASA researchers hope that the data gained from this mission will not only enable a greater understanding of how stars like our sun work, but also provide answers that might better protect against potentially catastrophic solar storms.
"Many of the systems we in the modern world rely on — our telecommunications, GPS, satellites and power grids — could be disrupted for an extended period of time if a large solar storm were to happen today," Justin C. Kasper, principal investigator at the Smithsonian Astrophysical Observatory, told Popular Mechanics. "Solar Probe Plus will help us predict and manage the impact of space weather on society."
Editor's note: This story was originally published on May 30, 2017, and has been updated with new information.