Into the great unknown: The Parker Solar Probe
From Fukushima to the darkest corners of the ocean, robots built for extreme environments and an appetite for discovery continue to enlighten our understanding of places too dangerous to tread. Those launched into deep space may be the most daring examples, continually pushing the limits of human ingenuity and expanding our understanding of the universe. In this series New Atlas will be profiling space probes, both past and present, tasked with pushing the boundaries of science by leading us into the great unknown. This week: a spacecraft built to "touch the Sun".
Name: The Parker Solar Probe
Launched: August 2018
Subject of study: The Sun
Current location: On its third lap around the Sun on a highly elliptical orbit, becoming closer and closer with each revolution
The inspiration for NASA’s Parker Solar Probe can be traced back more than half a century. In 1958 an astrophysicist by the name of Eugene Parker published a paper detailing what he believed to be high speed matter and magnetism emanating from the Sun, and flowing outward through the solar system.
We now know these to be solar winds and that they can have a destructive effect on GPS, satellites and electrical grids. A better understanding of them could better protect these systems, and also reveal clues about what gave rise to life on our planet. Scientists have spent decades working to better understand these forces. Only now thanks to advances in thermal engineering, are they able to send a machine in for a closer look.
The Parker Solar Probe, named after the astrophysicist whose curiosity inspired it, is built to fly closer to the Sun that any spacecraft in history. It is around the size of a small car and is fitted with a 4.5-inch-thick (11.4-cm) carbon composite plate that serves as a heat shield. This sophisticated sunshade is able to, quite remarkably, keep the probe’s equipment to a cool 85° F (29.5° C) by bouncing away the Sun’s energy, even in environments of nearly 2,500° F (1,377° C).
Somewhat counterintuitively, these temperatures will be encountered in the Sun’s outer atmosphere, known as the corona, which is around 300 times hotter than the surface. The reason the probe will be plying its trade here is because the corona is the birthplace of the most high-energy solar particles, and also happens to be where the solar winds go from subsonic to supersonic speeds.
Equipped with four suites of scientific instruments that include tools for analyzing magnetic fields, plasma, high-energy particles, as well as snapping images, the Parker Solar Probe studies this environment from right amid the thick of the action. In doing so, scientists anticipate it will reshape not just our understanding of the star at the center of our solar system, but other stars throughout the universe.
And while the best is yet to come from the Parker Solar Probe, it is has already notched up some significant achievements. In October 2018, just two months after launching, it came closer to the Sun than any spacecraft in history, with 1976’s German-American Helios 2 spacecraft the previous record-holder. It has also started relaying images from its travels back to Earth, including this first look from within the Sun’s atmosphere.
Now on its third orbit around the Sun, the probe has already completed three close flybys, each known as a perihleion. The most recent of these saw the probe skim past at around 15 million miles (24 million km) from the surface, at a speed of more than 213,000 mph (342,000 km/h).
The orbital path will continue to pull the probe into tighter and tighter proximity to the Sun, to a distance of just 3.8 million miles (6.1 million km) from the surface. It will complete its 24th and final lap in 2024, but you can expect data harvested from the Solar Parker Probe to continue shedding light on the Sun for many years beyond.
In next week’s installment of "Into the great unknown," we take a look at the secretive Soviet probe that would became the first spacecraft in history to land on another planet.