The Parker Solar Probe (PSP)is a NASA space probe launched in 2018 with the mission of making observations of the outer corona of the Sun. It will approach to within 9.86 solar radii (6.9 million km) from the center of the Sun, and by 2025 will travel, at closest approach, as fast as 690,000 km/h (430,000 mph). It is the fastest object ever built.