NASA has a new plan to send a spacecraft closer to the sun than any probe has ever gone. The ambitious Solar Probe mission will study the streams of charged particles the sun hurls into space from a vantage point within the sun’s corona — its outer atmosphere — where the processes that heat the corona and produce solar wind occur. At closest approach Solar Probe would zip past the sun at 125 miles per second, protected by a carbon-composite heat shield that must withstand up to 2,600 degrees Fahrenheit and survive blasts of radiation and energized dust at levels not experienced by any previous spacecraft.