Parker Solar Probe third stage firing. Animation of the third stage of the Parker Solar Probe's launch vehicle firing after launch on 12 August 2018. This third stage is a STAR 48BV solid rocket motor. Originally called Solar Probe, and then Solar Probe Plus, this mission was renamed in May 2017 after solar astrophysicist Eugene Parker. The mission is being carried out by NASA and Johns Hopkins University (JHU) Applied Physics Laboratory (APL). The unmanned probe has sensors to carry out five investigations of the Sun. To reach the Sun, the probe will carry out seven fly-bys past Venus. Using a solar shield for protection, the probe will gradually approach to within 6 million kilometres of the solar surface (photosphere), making its closest approaches to the Sun in 2024 and 2025.