The Parker Solar Probe will be the first spacecraft to fly into the low solar corona. It will assess the structure and dynamics of the Sun's coronal plasma and magnetic field, the energy flow that heats the solar corona and impels the solar wind, and the mechanisms that accelerate energetic particles.
The spacecraft's systems are protected from the extreme heat and radiation near the Sun by a solar shield. Incident solar radiation at perihelion is approximately 650 kW/m2, or 475 times the intensity at Earth orbit. The solar shield is hexagonal, mounted on the Sun-facing side of the spacecraft, 2.3 m (7.5 ft) in diameter, 11.4 cm (4.5 in) thick, and is made of reinforced carbon–carbon composite, which is designed to withstand temperatures outside the spacecraft of about 1,370 °C (2,500 °F). A white reflective alumina surface layer minimizes absorption. The spacecraft systems and scientific instruments are located in the central portion of the shield's shadow, where direct radiation from the Sun is fully blocked. If the shield were not between the spacecraft and the Sun, the probe would be damaged and become inoperative within tens of seconds. As radio communication with Earth will take about eight minutes, the Parker Solar Probe will have to act autonomously and rapidly to protect itself. This will be done using four light sensors to detect the first traces of direct sun light coming from the shield limits and engaging movements from fly wheels to reposition the spacecraft within the shadow again. According to project scientist Nicky Fox, the team describe it as "the most autonomous spacecraft that has ever flown".
The primary power for the mission is a dual system of solar panels (photovoltaic arrays). A primary photovoltaic array, used for the portion of the mission outside 0.25 AU, is retracted behind the shadow shield during the close approach to the Sun, and a much smaller secondary array powers the spacecraft through closest approach. This secondary array uses pumped-fluid cooling to maintain operating temperature of the solar panels and instrumentation.