The Parker Solar Probe was launched last weekend and has commenced its seven year journey to probe the outer corona of the Sun. It will approach to within 9 solar radii (6.2 million kilometers) from the “surface” of the Sun and will travel, at perihelion, or closest approach, as fast as 700,000 km/h. The spacecraft was named after physicist Eugene Parker, who first proposed the existence of the solar wind, a constant stream of particles escaping from the sun. This is the first time a NASA spacecraft was named after a living person. (Parker’s theoretical modeling in the mid-1950s was controversial, and when he submitted his results to The Astrophysical Journal, two reviewers rejected it!) The image above shows the evolution of the Parker Solar Probe’s orbit: over its lifetime it will make seven fly-bys of Venus, each time modifying its orbit to pass closer to the Sun. Over its nominal 7 year lifetime it will swing by the sun 26 times. (Image credit: NASA)