Parker Solar Probe was launched in 2018 and uses Venus’ gravity during seven flybys over nearly seven years to gradually bring its orbit closer to the outermost part of the Sun’s atmosphere, known as the corona.
Parker Solar Probe has been inserted into an eccentric orbit around the sun. The minimum distance of the probe from the Sun is being decreased over the seven-year mission using seven Venus flybys. During its prime mission, Parker Solar Probe will orbit the sun 24 times. The closest points of each orbit is well within Mercury’s distance from the Sun. On the final three orbits, Parker Solar Probe will reach within 3.7 million miles of the sun's surface. That is about seven times closer than the previous record-holder, the Helios-B spacecraft.
Parker Solar Probe is an extraordinary and historic mission, exploring what is arguably the last region of the solar system to be visited by a spacecraft: the sun’s atmosphere. Parker Solar Probe has repeatedly sampled the near-sun environment, revolutionizing our knowledge, and understanding of coronal heating and of the origin and evolution of the solar wind. Moreover, by making direct, in-situ measurements of the region where some of the most hazardous solar energetic particles are energized, Parker Solar Probe has made a fundamental contribution to our ability to characterize and forecast the radiation environments in which future space explorers will work and live. The spacecraft has a large Sun shield that was built to withstand temperatures of 2,500° F, so that the instruments that lie in the shadow of the Sun shield remain near room temperature.
Parker Solar Probe completed its fourth of seven planned Venus gravity assists in February of 2021 and will set up for its eighth and ninth close passes by the Sun, slated for April 29 and Aug. 9. During each of those passes, Parker Solar Probe will break its own record when it comes approximately 6.5 million miles (10.4 million kilometers) from the solar surface, about 1.9 million miles closer than the previous closest approach – or perihelion – of 8.4 million miles (13.5 million kilometers) on Jan. 17, 2021.