The Parker Solar Probe blasted off from Cape Canaveral Air Force Station in Florida on Sunday, setting itself on course to become both the fastest human craft ever launched (in the neighborhood of 430,000 miles per hour) and the first to probe the outer corona of the sun.
Per the BBC, NASA has since confirmed the probe successfully separated from its rocket and is proceeding on its mission as intended.
The $1.5 billion Parker probe will pass by the sun as close as 3.83 million miles from its visible surface, the photosphere—a number that sounds large in absolute terms but is nonetheless close enough to the star to expose it to temperatures of nearly 2,500 degrees Fahrenheit (1,377 degrees Celsius). According to NASA, the spacecraft is protected from solar radiation by a 4.5-inch-thick carbon-composite shield, which despite weighing just 160 pounds should allow onboard instruments to operate at room temperature even during the most intense parts of its journey.
“I realise that might not sound that close, but imagine the Sun and the Earth were a metre apart,” Johns Hopkins Applied Physics Laboratory-affiliated scientist Nicky Fox told the BBC. “Parker Solar Probe would be just 4cm away from the Sun.”
The probe also carries a memory card with the names of more than 1.1 million people who submitted their names to NASA.
The craft is named after 91-year-old University of Chicago astrophysicist Eugene Parker, the first to develop theories about the solar wind. Parker was on hand for the launch.
“It’s going to be absolutely phenomenal,” NASA Chief Scientist Jim Green told Space.com. “We’ve been wanting to do this for 60 years, ever since Eugene Parker got up and said, ‘I believe the sun is outgassing.”
Parker is expected to solve two longstanding solar mysteries, the first of which is how the solar wind accelerates from its near-motionless state upon leaving the sun’s surface to between 900,000 mph to 1.8 mph by the time it hits Earth’s orbit. Mission scientist Adam Szabo told Space.com, “Something happens in the corona where it steps on the accelerator and shoots out at supersonic speeds.”
The other mystery is how the corona ranges between 1.8 million to 5.4 million degrees Fahrenheit (1-3 million degrees Celsius), far hotter than the surface of the sun itself. Previous explanations have included magnetic fields and atmospheric “tornadoes,” though the Parker probe’s close flyby should help resolve the question.
As the New York Times noted, the Parker probe’s study of the solar wind could also help Earth scientists understand the potential impacts of a coronal mass ejection, periodic releases of plasma and magnetic field from the corona that have the capacity to knock out electrical systems:
Understanding the solar wind is of importance to scientists and policymakers because of its potential to devastate civilization.
Occasionally, a huge explosion, called a coronal mass ejection, erupts from the sun, sending a larger-than-usual deluge of particles into space. In 1859, one of those explosions made a direct hit on Earth, disrupting telegraph wires in America and Europe. If the same thing happened today, it could cause continentwide blackouts, potentially requiring months to years to repair.
In 2012, one of NASA’s sun-watching spacecraft, Stereo-A, detected an explosion comparable to the 1859 explosion. Fortunately, it was not aimed in Earth’s direction.
The Times also noted the Parker probe will use Venus’ gravity as a sort of braking system, slowing it enough to spiral towards the sun, where it will complete 24 orbits.