Image: The United Launch Alliance Delta IV Heavy rocket.
It is the first time NASA has named a spacecraft after someone still alive.
"We've been inside the orbit of Mercury and done fantastic things, but until you go and touch the sun, you can't answer these questions", Nicola Fox, mission project scientist, told CNN.
The mission is named for Dr Eugene Parker, a physicist at the University of Chicago who proposed the existence of solar wind. Saturday morning's launch attempt was foiled by last-minute technical trouble.
The corona holds the answers to many of scientists' outstanding questions about the Sun's activity and processes.
"The unique requirements of this mission made the Delta IV Heavy the flawless launch vehicle to deliver Parker Solar Probe into orbit with the highest precision", said Gary Wentz, ULA vice president of Government and Commercial Programs.
"Three, two, one, and liftoff!" said a NASA commentator as the Parker Solar Probe lit up the dark night sky aboard a Delta IV-Heavy rocket from Cape Canaveral, Florida at 3:31 am (0731 GMT). Parker watched the launch at Cape Canaveral and said it was his first time seeing a rocket blast off in person.
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Of course, the spacecraft won't actually touch the sun - its temperature is a ludicrously toasty 5,500 degrees Celcius, and would instantly destroy any probe.
NASA's science mission chief, Thomas Zurbuchen, was thrilled not only with the launch, but Parker's presence. On its very first brush with the sun, it will come within 15.5 million miles (25 million kilometers), easily beating the current record of 27 million miles (43 million kilometers) set by NASA's Helios 2 spacecraft in 1976.
The project, with a $1.5 billion price tag, is the first major mission under NASA's Living With a Star program.
Zurbuchen considers the sun the most important star in our universe - it's ours, after all - and so this is one of NASA's big-time strategic missions.
Instruments on board may also help to explain why the corona is hotter than the sun's surface by several orders of magnitude. A voice could be heard saying: "A daring mission to shed light on the mysteries of our closest star".
It is protected by an ultra-powerful heat shield that can endure unprecedented levels of heat, and radiation 500 times that experienced on Earth.
With a communication lag time of 16 minutes each way, the spacecraft must fend for itself at the sun.
More than 1 million names are aboard the spacecraft, submitted last spring by space enthusiasts, as well as photos of Parker, the man, and a copy of his 1958 landmark paper on solar wind.