On December 24, 2024, NASA’s Parker Solar Probe soared just 6.1 million km (3.8 million miles) above the surface of our home star, racing through the solar atmosphere at 692,000 km per hour (430,000 mph) — the fastest speed ever achieved by a human-made object; a signal received two days later confirmed the spacecraft had made it through the encounter safely and is operating normally.
NASA’s Parker Solar Probe approaching the Sun. Image credit: Johns Hopkins University Applied Physics Laboratory.
Close to the Sun, Parker Solar Probe relies on a carbon foam shield to protect it from the extreme heat in the upper solar atmosphere called the corona, which can exceed 500,000 degrees Celsius (1 million degrees Fahrenheit).
The shield was designed to reach temperatures of 1,427 degrees Celsius (2,600 degrees Fahrenheit), while keeping the instruments behind it shaded at a comfortable room temperature.
In the hot but low-density corona, the spacecraft’s shield is expected to warm to 982 degrees Celsius (1,800 degrees Fahrenheit).
“Flying this close to the Sun is a historic moment in humanity’s first mission to a star,” said Dr. Nicky Fox, the associate administrator of the Science Mission Directorate at NASA Headquarters.
“By studying the Sun up close, we can better understand its impacts throughout our Solar System, including on the technology we use daily on Earth and in space, as well as learn about the workings of stars across the Universe to aid in our search for habitable worlds beyond our home planet.”
“Parker Solar Probe is braving one of the most extreme environments in space and exceeding all expectations,” said Parker Solar Probe project scientist Dr. Nour Rawafi, a researcher at the Johns Hopkins Applied Physics Laboratory.
“This mission is ushering a new golden era of space exploration, bringing us closer than ever to unlocking the Sun’s deepest and most enduring mysteries.”
Parker Solar Probe’s record close distance of 6.1 million km (3.8 million miles) may sound far, but on cosmic scales it’s incredibly close. Image credit: NASA / APL.
“It’s monumental to be able to get a spacecraft this close to the Sun,” said Parker Solar Probe mission systems engineer John Wirzburger, a researcher at the Johns Hopkins Applied Physics Laboratory.
“This is a challenge the space science community has wanted to tackle since 1958 and had spent decades advancing the technology to make it possible.”
By flying through the solar corona, Parker Solar Probe can take measurements that help scientists better understand how the region gets so hot, trace the origin of the solar wind and discover how energetic particles are accelerated to half the speed of light.
“The data are so important for the science community because it gives us another vantage point,” said Dr. Kelly Korreck, a program scientist at NASA Headquarters.
“By getting firsthand accounts of what’s happening in the solar atmosphere, Parker Solar Probe has revolutionized our understanding of the Sun.”
So far, the spacecraft has only transmitted that it’s safe, but soon it will be in a location that will allow it to downlink the data it collected on this latest solar pass.
“The data that will come down from the spacecraft will be fresh information about a place that we, as humanity, have never been. It’s an amazing accomplishment,” said Dr. Joe Westlake, the director of the Heliophysics Division at NASA Headquarters.
The spacecraft’s next planned close solar passes come on March 22 and June 19, 2025.
