NASA’s Parker Solar Probe Makes 27th Swing Around the Sun
NASA’s Parker Solar Probe completed its 27th close approach to the Sun on March 11, again matching its record distance of 3.8 million miles (6.2 million kilometers) from the solar surface. The flyby allowed the spacecraft to conduct measurements of the solar wind and solar activity, contributing to our understanding of how the Sun’s atmosphere changes throughout the solar cycle.
The durable spacecraft checked in with flight controllers at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland — where Parker Solar Probe was also designed and built — on March 14, transmitting a beacon tone indicating that its systems were operating normally. Speeding on a path around the Sun that limited communications with Earth, Parker had been out of contact and operating autonomously, as planned, for about a month leading up to, and during, closest approach.
During this solar encounter, from March 6 through March 16, Parker’s four scientific instrument packages gathered data from inside the Sun’s atmosphere, or corona. Parker will begin returning detailed telemetry on its status on March 17, with science data transmission for this solar encounter set to start the following day.
Parker’s observations of the solar wind and solar events, such as coronal mass ejections and the aftermaths of flares, 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 also equaled its record-setting speed of 430,000 miles per hour (687,000 kilometers per hour) — a mark that, like the distance to the Sun, was set during a close approach on Dec. 24, 2024, and matched during 2025 flybys on March 22, June 19, Sept. 16 and Dec. 13.
Parker launched in August 2018. At the time, the Sun was near the minimum of its 11-year activity cycle. In 2024, representatives from NASA, the National Oceanic and Atmospheric Administration (NOAA), and the international Solar Cycle Prediction Panel announced that the Sun has reached its solar maximum period. Parker’s 27 encounters with the Sun reflect this change over time, sampling the Sun’s atmosphere from quiet to very active periods. Parker Solar Probe will remain in this orbit around the Sun and continue making observations into the declining phase of solar activity.
The next steps for the mission in late 2026 and beyond are formally under NASA review.
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.
By Mike Buckley
Johns Hopkins Applied Physics Laboratory
