It’s a mission that’s been in the works for nearly 60 years. NASA says it will launch a spacecraft in 2018 to “touch the sun,” sending it closer to the star’s surface than ever before.
The spacecraft is small – its instruments would fit into a refrigerator — but it’s built to withstand temperatures of more than 2,000 degrees Fahrenheit, all the while maintaining room temperature inside the probe.
“Even though the sun is so close to us, there’s actually a lot about it we don’t understand,” says heat shield lead engineer Betsy Congdon from the Johns Hopkins University Applied Physics Laboratory.
Scientists are hoping the data gathered might solve some of the big mysteries about the sun.
First, what allows the sun to fling winds out at supersonic speeds? Understanding this will be important for protecting astronauts during space travel, Congdon says, and solar events can damage satellites and knock out power on Earth.
“Unless we can explain what is going on up close to the sun, we will not be able to accurately predict space weather effects that can cause havoc at Earth,” NASA says.
Second, why is the sun’s atmosphere actually hotter — 300 times hotter — than its surface? “That defies the laws of nature. It’s like water flowing uphill. It shouldn’t happen,” mission project scientist Nicola Fox of the Johns Hopkins lab said at a news conference.
The probe is expected to complete 24 orbits over the course of more than six years, looping closer to the sun and eventually hurtling toward it at a speed of 450,000 miles per hour. At that speed, you could travel from Philadelphia to Washington, D.C., in one second. Here’s a map of the route:
It’s worth noting that the probe will not literally touch the sun’s surface — the closest it will get is about 3.9 million miles away.
But Congdon says that’s actually very close. “If you think about a football field and the sun’s sitting on one side and the Earth’s sitting on the other, we’re getting within the 5-yard line,” she says. It’s about seven times closer than any previous mission.
The circuitous route involves careening closer to the sun and then back out to Venus, which means wild oscillations in temperature. Congdon says protecting the probe’s scientific instruments from getting fried is “quite an engineering feat.”
It basically involves “putting up a big umbrella,” she says. The shield is an 8-foot wide disc made of layers of carbon, which would get burnt to a charcoal crisp if it weren’t for the fact that there’s no oxygen in space.
Today, NASA announced that it is naming the spacecraft after Eugene Parker, a retired physicist who predicted the existence of solar winds almost 60 years ago. He is about to turn 90, and this is the first time NASA has named a spacecraft after a researcher during their lifetime.
Parker’s ideas fundamentally changed the study of the sun.
But at this point, Fox compared the state of the field with learning about weather by looking out the window.
“You can see the sun is shining, you can see the birds are singing. But until you actually go out, you have no idea quite how hot it is out there or how windy it is or what the conditions are like,” Fox said.
“I really think we’ve come as far as we can with looking at things and it’s now time to go up and pay it a visit.”
The European Space Agency also has plans to launch a probe toward the sun.
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