CAPE CANAVERAL, Fla. — NASA is sending a spacecraft straight into the sun’s glittering crown, an atmospheric region so hot and harsh any normal visitor would wither.
Set to launch early Saturday, the Parker Solar Probe is as heat-resistant as a spacecraft gets, essential for exploring our star closer than ever before.
The U.S. got a glimpse of the sun’s glowing, spiky crown, or corona, during last August’s coast-to-coast total solar eclipse. “Well, Parker Solar Probe’s going to be in there,” said project scientist Nicola Fox of Johns Hopkins University.
Here’s why the Parker spacecraft is so tough and why scientists are so hot for this first-of-its-kind mission:
Parker’s lightweight heat shield is just 4 ½ inches (11 centimeters) thick. But it can withstand 2,500 degrees Fahrenheit (1,370 degrees Celsius) as well as extreme radiation, thanks to its high-tech carbon. Although the corona reaches millions of degrees, it’s a wispy, tenuous, environment and so the spacecraft won’t need to endure such severe temperatures. The 8-foot (2.4-meter) shield will face the sun during the close solar encounters, shading the science instruments in the back and keeping them humming at a cool 80 degrees Fahrenheit (27 degrees Celsius). As one scientist notes, this is a shield Captain America would envy.
SEVEN YEARS IN HOT PURSUIT
The spacecraft’s path to the sun runs past Venus. It will fly by our solar system’s hottest planet seven times over seven years, using the gravity of Venus to shrink its own oval orbit and draw increasingly closer to the sun. The first Venus flyby is in October, followed by the first dip into the sun’s corona in November. There will be 24 orbits between Venus and the sun, with the final three putting Parker closest to the sun — just 3.8 million miles (6 million kilometers) out — in 2024 and 2025. That’s a scant 4 percent of the 93 million miles (150 million kilometers) between Earth and the sun.
The records will start falling as soon as Parker takes its first run past the sun.. The current close-to-the-sun champ, NASA’s former Helios 2, got within 27 million miles (43 million kilometers) in 1976. Parker will come within 15.5 million miles (25 million kilometers) in November and then start beating its own record. During its closest solar approaches, the spacecraft will hurtle through the corona at 430,000 mph (690 kph), setting a speed record.
Our yellow dwarf star is, in many …read more
Source:: Deseret News – U.S. & World News