NASA’s Parker Solar Probe Completes 18th Close Approach to the Sun

NASA’s Parker Solar Probe completed its 18th close approach to the Sun on Dec. 28, 2023, matching its own distance record by skimming just about 4.51 million miles (7.26 million kilometers) from the solar surface.

The close approach (known as perihelion) occurred at 7:56 p.m. EST, with Parker Solar Probe traveling at 394,736 miles per hour (635,266 kilometers per hour) around the Sun – also matching the speed record for the 17th solar encounter. The milestone also marked the midway point in the mission’s 18th solar encounter, which began Dec. 24, 2023, and continued through Jan. 2, 2024. 

An illustration of Parker Solar Probe's orbit shows the spacecraft's eighteenth solar encounter on Dec. 28, 2023, at 4.51 million miles from the Sun.
Parker Solar Probe’s 18th orbit included a perihelion that brought the spacecraft within 4.51 million miles of the Sun. Credit: NASA/Johns Hopkins APL/Steve Gribben

The spacecraft entered the encounter in good health, with all systems operating normally. Parker Solar Probe checked back in with mission operators at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland – where the spacecraft was also designed and built – by sending a status beacon tone on Jan. 5.

By Michael Buckley
Johns Hopkins Applied Physics Laboratory

For the Record: Parker Solar Probe Sets Distance, Speed Marks on 17th Swing by the Sun

NASA’s Parker Solar Probe completed its 17th close approach to the Sun on Sept. 27, 2023, breaking its own distance record by skimming just 4.51 million miles (7.26 million kilometers) from the solar surface.

Set up by a gravity-assist flyby of Venus on Aug. 21, the close approach (known as perihelion) occurred at 7:28 p.m. EDT, with Parker Solar Probe moving 394,736 miles per hour (635,266 kilometers per hour) around the Sun – another record. The milestone also marked the midway point in the mission’s 17th solar encounter, which began Sept. 22 and continues through Oct. 3.

An illustration of Parker Solar Probe's orbit shows the beginning of the spacecraft's seventeenth solar encounter on Sept. 22, 2023, at 22.8 million miles from the Sun. The space craft reaches its closest approach to the Sun on Sept. 27, 2023, at 4.5 million miles. The orbit ends on Oct. 3, 2023.
Parker Solar Probe’s 17th orbit included a perihelion that brought the spacecraft within 4.51 million miles of the Sun. Credit: NASA/Johns Hopkins APL/Steve Gribben

The spacecraft entered the encounter in good health, with all systems operating normally. Parker Solar Probe is scheduled to check back in with mission operators at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland – where the spacecraft was also designed and built – by sending a stream of telemetry (status data) on Oct. 1.

The spacecraft will transmit science data from the encounter – largely covering the properties, structure, and behavior of the solar wind as it launches off the Sun – back to Earth from Oct. 4 – 19.

By Michael Buckley
Johns Hopkins Applied Physics Laboratory

Course Correction Keeps Parker Solar Probe on Track for Venus Flyby

An illustration of Parker Solar Probe flying through solar material.
Artist’s concept of Parker Solar Probe. Credit: NASA’s Goddard Space Flight Center

NASA’s Parker Solar Probe executed a short maneuver on Aug. 3, 2023, that kept the spacecraft on track to hit the aim point for the mission’s sixth Venus flyby on Monday, Aug. 21, 2023. ​

Operating on preprogrammed commands from mission control at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, Parker fired its small thrusters for 4.5 seconds, enough to adjust its trajectory by 77 miles and speed up – by 1.4 seconds – its closest approach to Venus. The precise timing and position are critical to that flyby, the sixth of seven approaches in which Parker uses the planet’s gravity to tighten its orbit around the Sun.

“Parker’s velocity is about 8.7 miles per second, so in terms of changing the spacecraft’s speed and direction, this trajectory correction maneuver may seem insignificant,” said Yanping Guo, mission design and navigation manager at APL. “However, the maneuver is critical to get us the desired gravity assist at Venus, which will significantly change Parker’s speed and distance to the Sun”.

Parker Solar Probe will be moving 394,742 miles per hour when it comes within just 4.5 million miles from the Sun’s surface – breaking its own record for speed and solar distance – on Sept. 27, 2023. Follow the spacecraft’s journey through the inner solar system on the Parker Solar Probe website.

By Michael Buckley
Johns Hopkins Applied Physics Laboratory

NASA’s Parker Solar Probe Completes 16th Close Approach to the Sun

Parker Solar Probe’s 16th orbit included a perihelion that brought the spacecraft within 5.3 million miles of the Sun. Credits: NASA/Johns Hopkins APL/Mike Yakovlev/Josh Diaz

NASA’s Parker Solar Probe accomplished a milestone on June 27, 2023 – its 16th orbit of the Sun. This included a close approach to the Sun (known as perihelion) on June 22, 2023, where the spacecraft came within 5.3 million miles of the solar surface while moving at 364,610 miles per hour. The spacecraft emerged from the solar flyby healthy and operating normally.

On Aug. 21, 2023, Parker Solar Probe will swing past Venus for its sixth flyby of the planet. To prepare for a smooth course, the mission team at the Johns Hopkins Applied Physics Laboratory (APL) applied a small trajectory correction maneuver on June 7, 2023, the first course correction since March 2022. This flyby will be the sixth of seven planned flybys of Venus during Parker’s primary mission. Parker uses Venus’ gravity to tighten its orbit around the Sun and set up a future perihelion at just 4.5 million miles from the Sun’s surface. As the Sun becomes increasingly active, this perihelion will be especially important to learning more about heliophysics.

Parker Solar Probe was developed as part of NASA’s Living With a Star program to explore aspects of the Sun-Earth system that directly affect life and society. The Living With a Star program is managed by the agency’s Goddard Space Flight Center in Greenbelt, Maryland, for NASA’s Science Mission Directorate in Washington. APL designed, built, and operates the spacecraft and manages the mission for NASA.