Parker Solar Probe Completes Its Fifth Venus Flyby

NASA’s Parker Solar Probe is speeding in toward the Sun after a swing past Venus on Oct. 16, successfully using the planet’s gravity to shape its path for its next closest approach to our star.

At just after 5:30 a.m. EDT, moving about 15 miles (24 kilometers) per second, the spacecraft swooped 2,370 miles (3,814 kilometers) above Venus’ surface. Such gravity assists are essential to the mission to bring Parker Solar Probe progressively closer to the Sun; the spacecraft counts on the planet to reduce its orbital energy, which in turn allows it to travel closer to the Sun and measure the properties of the solar wind near its source.

This was the fifth of seven planned Venus gravity assists. The flyby reduced Parker Solar Probe’s orbital speed by about 6,040 miles per hour (9,720 kilometers per hour), and set it up for its 10th close pass (or perihelion) by the Sun, on Nov. 21.

animated image showing parker solar probe flying by Venus
NASA’s Parker Solar Probe is speeding in toward the Sun after a swing past Venus on Oct. 16, 2021, successfully using the planet’s gravity to shape its path for its next closest approach to our star. This was the fifth of seven planned Venus gravity assists. The flyby reduced Parker Solar Probe’s orbital speed by about 6,040 miles per hour (9,720 kilometers per hour), and set it up for its 10th close pass (or perihelion) by the Sun, on Nov. 21, 2021. Credit: NASA/Johns Hopkins APL/Steve Gribben

Parker Solar Probe will break its own distance and speed records on that closest approach, when it comes approximately 5.3 million miles (8.5 million kilometers) from the Sun’s surface — some 1.2 million miles (1.9 million kilometers) closer than the previous perihelion on Aug. 13 – while reaching 101 miles (163 kilometers) per second, or 364,621 miles per hour. Assisted by two more Venus flybys, in August 2023 and November 2024, Parker Solar Probe will eventually come within 4 million miles (6.2 million kilometers) of the solar surface in December 2024.

Parker Solar Probe, which was designed and built at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, is healthy and its systems are operating normally after the Oct. 16 Venus flyby. The flyby operation was monitored by the spacecraft and mission operations teams at APL, through NASA’s Deep Space Network.

By Mike Buckley
Johns Hopkins University Applied Physics Lab