NASA's Parker Solar Probe Sails Through 25th Sun Flyby

NASA's Parker Solar Probe Sails Through 25th Sun Flyby
by Mike Buckley for APL
Baltimore MD (SPX) Sep 25, 2025

NASA's Parker Solar Probe completed its 25th close approach to the Sun on Sept. 15, matching its record distance of 3.8 million miles (6.2 million kilometers) from the solar surface.

Parker Solar Probe checked in with flight controllers at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland - where the spacecraft was also designed and built - on Sept. 18, transmitting a beacon tone indicating that its systems were operating normally. The spacecraft was out of contact with Earth and operating autonomously during the close approach.

The spacecraft also equaled its record-setting speed of 430,000 miles per hour (687,000 km per hour) - a mark that, like the distance, was set and subsequently matched during close approaches on Dec. 24, 2024; March 22, 2025; and June 19, 2025. Parker Solar Probe will remain in this orbit around the Sun and continue making observations. The next steps for the mission - in 2026 and beyond - are formally under NASA review.

During this solar encounter - which began Sept. 10 and ends Sept. 20 - Parker's four scientific instrument packages are gathering unique observations from inside the Sun's atmosphere, or corona. The flyby, as the fourth at this distance and speed, is allowing the spacecraft to conduct unrivaled measurements of the solar wind and solar activity while the Sun is in a more active phase of its 11-year cycle.

Parker will begin returning science data from the encounter on Sept. 23. Parker's observations of the solar wind and solar events, such as flares and coronal mass ejections, are critical to advancing humankind's understanding of the Sun and the phenomena that drive high-energy space weather events that pose risks to astronauts, satellites, air travel, and even power grids on Earth. Understanding the fundamental physics of space weather enables more reliable prediction of astronaut safety during future deep-space missions to the Moon and Mars.

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