Researchers using Parker Solar Probe data released a new wave of research papers in a special supplement of The Astrophysical Journal on Feb. 3, 2020. The supplement, titled Early Results from Parker Solar Probe: Ushering a New Frontier in Space Exploration, includes some 47 papers with new findings based on the mission’s first three solar flybys. Several other papers still under review will be published later as part of this same issue. The introduction for the issue was written by Marcia Neugebauer, who first confirmed the existence of the solar wind after it was predicted by Eugene Parker — namesake of Parker Solar Probe — in 1958.
NASA’s Parker Solar Probe is healthy and operating as designed following its fourth close approach to the Sun, called perihelion, on Jan. 29.
Mission controllers at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, received a “status A” beacon from the spacecraft at 5:20 a.m. EST on Feb. 1. Status A is the best of four possible status signals, and indicates that the spacecraft is operating nominally and the instrument suites are collecting science data. This status also indicates that any minor issues that may have occurred were identified and resolved by Parker Solar Probe’s onboard autonomy and fault management systems.
During this perihelion, Parker Solar Probe broke its own records for speed and proximity to the Sun for a human-made object. The spacecraft reached a speed of 244,255 miles per hour (about 393,044 kilometers per hour) as it whipped around the Sun at a distance of 11.6 million miles (about 18.6 million kilometers).
Parker Solar Probe’s heat shield, called the Thermal Protection System, or TPS, reached new record temperatures as well. At this distance from the Sun, computer modeling estimates show that the Sun-facing side of the TPS experienced a blazing 1,134 degrees Fahrenheit (612 degrees C), about 300 degrees hotter than encountered on the spacecraft’s previous three perihelia. The spacecraft and instruments behind this protective heat shield remained at a temperature of about 85 F (30 C). During the spacecraft’s closest three perihelia in 2024-25, the TPS will see temperatures around 2,500 F (1,370 C).
As the mission team learns more about operations and conditions in this region of space, they have increased the amount of time the instruments are on and gathering data. Parker Solar Probe’s fourth solar encounter phase began on Jan. 23, and the spacecraft will continue to acquire science data through Feb. 29, beyond the originally-planned end of the solar encounter phase on Feb. 4. This solar encounter data will be downlinked to Earth beginning in March.