NASA’s Parker Solar Probe launched yesterday (August 12) from Space Launch Complex-37 at Cape Canaveral Air Force Station in Florida, rising off the pad atop a United Launch Alliance Delta IV Heavy rocket at 3:31 a.m. EDT. At 5:33 a.m. EDT, the mission operations manager reported that the car-sized spacecraft was healthy and operating normally. The probe will offer a first glimpse of regions of solar wind, helping scientists understand how the Sun’s atmosphere affects the space environment, satellites and electronics.
Illustration of NASA’s Parker Solar Probe approaching the Sun. Image credit: NASA / Johns Hopkins University Applied Physics Laboratory / Steve Gribben.
Parker Solar Probe is part of NASA’s Living with a Star program to explore aspects of the Sun-Earth system that directly affect life and society.
The mission is named for Dr. Eugene Parker, famed solar physicist who in 1958 first predicted the existence of the solar wind, the stream of charged particles and magnetic fields that flow continuously from the Sun, bathing Earth. It’s the first NASA mission to be named for a living researcher.
“This mission truly marks humanity’s first visit to a star that will have implications not just here on Earth, but how we better understand our Universe. We’ve accomplished something that decades ago, lived solely in the realm of science fiction,” said Dr. Thomas Zurbuchen, associate administrator of NASA’s Science Mission Directorate.
“Today’s launch was the culmination of six decades of scientific study and millions of hours of effort. Now, Parker Solar Probe is operating normally and on its way to begin a seven-year mission of extreme science,” said mission scientist Dr. Andy Driesman, from the Johns Hopkins University Applied Physics Laboratory.
“It was a very quiet launch countdown, it went off like clockwork. Parker Solar Probe has been one of our most challenging missions to date. I’m very proud of the team that worked to make this happen. We at NASA and the Launch Services Program are thrilled to be part of this mission,” said Dr. Omar Baez, NASA Launch Director.
“Eight long years of hard work by countless engineers and scientists is finally paying off,” said mission scientist Dr. Adam Szabo, of NASA’s Goddard Space Flight Center.
During the first week of its journey, Parker Solar Probe will deploy its high-gain antenna and magnetometer boom. It also will perform the first of a two-part deployment of its electric field antennas. Instrument testing will begin in early September and last approximately four weeks, after which the spacecraft can begin science operations.
Over the next two months, the probe will fly towards Venus, performing its first Venus gravity assist in early October that whips the spacecraft around the planet, using Venus’s gravity to trim the spacecraft’s orbit tighter around the Sun.
This first flyby will place Parker Solar Probe in position in early November to fly as close as 15 million miles (24 million km) from the Sun — within the blazing solar atmosphere, known as the corona — closer than anything made by humanity has ever gone before.
Throughout its seven-year mission, the spacecraft will make six more Venus flybys and 24 total passes by the Sun, journeying steadily closer to the star until it makes its closest approach at 3.8 million miles (6.1 million km).
At this point, the probe will be moving at roughly 430,000 mph (692,000 km per hour), setting the record for the fastest-moving object made by humanity.
In an orbit so close to the Sun, the real challenge is to keep the spacecraft from burning up.
“NASA was planning to send a mission to the solar corona for decades, however, we did not have the technology that could protect a spacecraft and its instruments from the heat,” Dr. Szabo said.
“Recent advances in materials science gave us the material to fashion a heat shield in front of the spacecraft not only to withstand the extreme heat of the Sun, but to remain cool on the backside.”
The heat shield is made of a 4.5-inch (11.4 cm) thick carbon composite foam material between two carbon fiber face sheets. While the Sun-facing side simmers at 2,500 degrees Fahrenheit (1,371 degrees Celsius), behind the shield the spacecraft will be a cozy 85 degrees Fahrenheit.
Parker Solar Probe will set its sights on the corona to solve long-standing, foundational mysteries of our Sun.
What is the secret of the scorching corona, which is more than 300 times hotter than the Sun’s surface, thousands of miles below? What drives the supersonic solar wind? And finally, what accelerates solar energetic particles, which can reach speeds up to more than half the speed of light as they rocket away from the Sun?
“The most important question to be answered is how the Sun heats the solar corona, the region above the surface of the Sun, and then drives the huge, highly supersonic solar wind and creates the bubble within which the Solar System resides,” said Dr. Gary Zank, director of the Center for Space Plasma and Aeronomic Research at the University of Alabama in Huntsville.
“The surface of the Sun is relatively cool, but the atmosphere above is heated to more than a million degrees over a relatively short distance. We do not know how or what the physical process is. We have some ideas, and by measuring the distribution function, we will be able to finally quantitatively identify the physical processes that lead to the existence of the solar wind.”
“Besides informing us of the physics underlying the atmosphere of our Sun, we will learn about the corresponding physics of all stars that are like the Sun. It will be the first in situ exploration of the atmosphere of a star. The work will therefore be incredibly far-reaching,” he added.
“Exploring the Sun’s corona with a spacecraft has been one of the hardest challenges for space exploration,” said mission scientist Dr. Nicola Fox, of the Johns Hopkins University Applied Physics Laboratory.
“We’re finally going to be able to answer questions about the corona and solar wind raised by Gene Parker in 1958 and I can’t wait to find out what discoveries we make. The science will be remarkable.”
