NASA has unveiled a "cutting-edge heat shield" that will make it possible for a space probe to "touch the sun" — or at least get a spacecraft to within 4 million miles of it, which scientists are hailing as nothing short of a "revolutionary" development in space technology.
The announcement was made via the official site NASA.gov as the launch of the Parker Solar Probe is readied for its August 4 liftoff date: "The launch of Parker Solar Probe, the mission that will get closer to the Sun than any human-made object has ever gone, is quickly approaching, and on June 27, 2018, Parker Solar Probe’s heat shield — called the Thermal Protection System, or TPS — was installed on the spacecraft."
The heat shield, measuring eight feet in diameter, will reach nearly 2,500 degrees Fahrenheit while keeping the probe's instruments at about 85 degrees, allowing the probe to "collect unprecedented data" on the giant ball of fire and earth's most vital source of energy, previously impossible to access without a protective shield, and will allow "the spacecraft’s orbit will carry it to within 4 million miles of the Sun's fiercely hot surface," according to NASA.
For comparison, the closest that planet Mercury ever gets to the sun during its orbit is approximately 29 million miles, allowing surface temperatures to reach 800 degrees Fahrenheit (430 °C). And Earth’s average distance to the sun is 93 million miles. At the core of the sun, temperatures can reach more than 27 million degrees Fahrenheit (15 million °C), scientists have estimated.
Parker #SolarProbe will fly closer to the Sun than any human-made object before. A state-of-the-art heat shield (just installed @JHUAPL) makes this extreme journey possible, keeping the spacecraft at 85° F — even while the shield reaches 2,500° F! 🛡☀️https://t.co/FpAfv18v8p pic.twitter.com/Q2swFYmghr— NASA Sun & Space (@NASASun) July 5, 2018
The TPS shield will enable the probe to reach more than seven times closer than any spacecraft has come before, to within the sun's outer atmosphere known as the corona, as a NASA statement explains, "Parker Solar Probe will employ a combination of in situ measurements and imaging to revolutionise our understanding of the corona and expand our knowledge of the origin and evolution of the solar wind."
And further NASA has defined the mission as to "trace how energy and heat move through the solar corona and to explore what accelerates the solar wind as well as solar energetic particles."
The description of the heat shield is as follows:
The heat shield is made of two panels of superheated carbon-carbon composite sandwiching a lightweight 4.5-inch-thick carbon foam core. The Sun-facing side of the heat shield is also sprayed with a specially formulated white coating to reflect as much of the Sun’s energy away from the spacecraft as possible.
The Parker Solar Probe itself is about the size of a car but is light-weight, along with its protective shield:
The heat shield itself weighs only about 160 pounds — here on Earth, the foam core is 97 percent air. Because Parker Solar Probe travels so fast — 430,000 miles per hour at its closest approach to the Sun, fast enough to travel from Philadelphia to Washington, D.C., in about one second — the shield and spacecraft have to be light to achieve the needed orbit.
The agency has previously said the probe will "touch the sun" when it arrives at the star's outer atmosphere, revealing more than ever before about its mysterious "inner workings," according to researchers.