The Solar Probe Plus is the first mission expected to fly into the Sun's upper atmosphere and “touch” the star. The goal of the mission is to study the streams of charged particles that Sun hurls into space from the inside its corona - where the processes of heating the outer atmosphere and producing solar wind take place - determine the structure and dynamics of the magnetic fields at the sources of solar winds, and explore dusty plasma near the Sun and its impact on the solar wind and energetic particle formation.
The Probe will combine the in-place and remote measurements to fulfil its scientific goals, to gain insight into the processes of the fundamental importance in the interconnected system of the Sun and near-Earth space, a system that impacts changes in the space weather, and directly influences our satellites. It is part of NASA's “Living With a Star” program, an initiative focused on aspects of the sun-Earth system that directly affect human lives and society.
The spacecraft is scheduled to launch during a 20-day window, opening on July 31, 2018. The solar arrays will retract and extend following the spacecraft swings toward or away from the Sun, during the loops around the inner solar system. At the closest approach, the spacecraft has to be capable of withstanding solar intensity over 500 times stronger than those experienced by spacecraft orbiting Earth.
Reference: (Source) http://thewatchers.adorraeli.com/2016/08/09/solar-probe-plus-to-fly-into-the-sun-s-upper-atmosphere-and-touch-the-star/
Featured image: Artist rendering of Solar Probe Plus, solar panels folded into the shadows of its protective shield, as it gathers data on its approach to the Sun. Credit: NASA/JHUAPL