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A few weeks ago, I wrote about several past and future missions for space probes. One probe, Juno, is gearing up for a trip to Jupiter, where it will be exposed to extreme heat and radiation. But those conditions are nothing compared with the conditions of the sun. NASA recently announced its Solar Probe Plus mission, an unprecedented project to send a spacecraft to the sun by 2018.
The Solar Probe Plus will mark mankind's first visit to a star. Despite decades of careful research about the sun, many mysteries still exist about aspects like its atmosphere (the corona) and winds. Unfortunately for Earth-bound astronomers and scientists, these mysteries can only be unlocked through up-close measurements and observations. The Solar Probe Plus is being designed to undertake these experiments.

The
Solar Probe Plus probe will get closer to the sun than any spacecraft before it
(source: NASA).
"The experiments selected for Solar Probe Plus are specifically designed to solve two key questions of solar physics—why is the sun's outer atmosphere so much hotter than the sun's visible surface, and what propels the solar wind that affects Earth and our solar system?" says Dick Fisher, director of NASA's Heliophysics Division in Washington, D.C., in a NASA press release. "We've been struggling with these questions for decades, and this mission should finally provide those answers."
The spacecraft will enter into the sun's atmosphere at a distance of about 6.4 million kilometers (4 million miles) from the star's surface. No other craft has ever visited this region of space, where temperatures exceed 1,400 degrees Celsius (2,550 degrees Fahrenheit). The car-sized machine has a revolutionary carbon-composite heat shield to protect it from this heat and frequent blasts of intense radiation.
In 2009, NASA invited research proposals for the craft's objectives. Among a total of 13, five proposals were chosen by a team of NASA researchers and outside scientists. Total funding of approximately $180 million will be awarded to the projects for preliminary analysis, design, development and tests.

