We're sending a spacecraft to the sun. That's hot.

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Mar 5, 2017

Could we really send a spacecraft to the sun without turning it into a mass of molten metal? NASA seems to think so.

The Solar Probe Plus may sound like something out of a sci-fi novel, but this very real collaborative effort between NASA and the Johns Hopkins University Applied Physics Laboratory is expected to get closer than anything ever made by human hands. It will shed light on solar phenomena by observing the great ball of fire from 4 million miles away. If that's not hot enough for you, consider that up until now we've been trying to illuminate its mysteries from 93 million miles away.

Handling the heat is a challenge scientists have equipped the probe for in anticipation of its 2018 launch. Needless to say, anything venturing this close to extreme radiation needs much more than SPF. Protecting it from temperatures of up to 2,500 degrees Fahrenheit will be a carbon-composite shield 4.5 inches thick. Heat that manages to penetrate the shield will be re-radiated into space by specialized heat tubes called thermal radiators, and its electrical circuits will also have extra protection against emissions that could mess with its memory. That's some heavy-duty sunblock.

NASA and JHU's mission goes beyond curiosity to "answer pressing questions about the corona and provide new data on solar activity and make critical contributions to our ability to forecast major space-weather events that impact life on Earth," as stated on the official Solar Probe Plus website. Meaning not only could it light up some answers science has been in the dark about but it may also prevent potential power outages and trillions of dollars' worth of technological damage due to a solar temper tantrum.

One mystery that has remained a hot topic in astrophysics is why the sun's corona (atmosphere) scorches so much more than its photosphere (surface). Try 3.5 million degrees Fahrenheit vs. a mere 10,000. Why temperatures get cooler instead of hotter closer to the star’s surface -- which means that energy is somehow moved from the sun’s interior to its exterior -- has long baffled researchers. While investigations got warmer when a 2011 breakthrough found jets of plasma spewing near the surface, we're still relatively cold as to the answer.

Burning questions also include why the sun sometimes shoots out high-energy particles and how solar winds get their supercharged speed. Astronauts and spacecraft without proper protection are vulnerable to solar energetic particles, which are emitted from solar flare sites or shock waves left in the wake of a coronal mass ejection. Understanding them further could be valuable to the design of future spacecraft and protective gear. Solar winds propel charged particles at a million miles an hour, influencing comets faster than they can shoot through space (which is why their tails never face the sun), but scientists continue to speculate over how these winds accelerate.

While the Solar Probe Plus will be flying solo, ethical questions over whether a manned mission would ever survive hang in the air. Some believe that it could be possible, but involving human lives is an ethical dimension better off left unexplored for now. NASA is probably better off investing in research and development for an even more advanced probe that could potentially survive the sun's brutal atmosphere to reveal the secrets of its surface.

While no one is going to be singing "Fly Me to the Sun" anytime soon, the future of the Solar Probe Plus looks bright.

(via Space.com)