NASA launches daring space probe to ‘touch the sun’

A NASA spacecraft zoomed toward the sun on Sunday on an unprecedented quest to get closer to our star than anything ever sent before.

As soon as this fall, the Parker Solar Probe will fly straight through the wispy edges of the sun’s corona, or outer atmosphere, that was visible during last August’s total solar eclipse.

It eventually will get within six million kilometres of the surface in the years ahead, staying comfortably cool despite the extreme heat and radiation, and allowing scientists to vicariously explore the sun in a way never before possible.

No wonder scientists consider it the coolest, hottest mission under the sun, and what better day to launch to the sun than Sunday as NASA noted.

“All I can say is, ‘Wow, here we go.’ We’re in for some learning over the next several years,” said Eugene Parker, the 91-year-old astrophysicist for whom the spacecraft is named.

Protected by a revolutionary new carbon heat shield and other hi-tech wonders, the spacecraft will zip past Venus in October.

That will set up the first solar encounter in November.

Altogether, the Parker probe will make 24 close approaches to the sun on the seven-year, $US1.5 billion ($2.1 billion) undertaking.

For the second straight day, thousands of spectators jammed the launch site in the middle of the night as well as surrounding towns, including Parker and his family.

He proposed the existence of solar wind — a steady, supersonic stream of particles blasting off the sun — 60 years ago.

It was the first time NASA named a spacecraft after someone still alive, and Parker wasn’t about to let it take off without him. Saturday morning’s launch attempt was foiled by last-minute technical trouble.

But Sunday gave way to complete success.

The Delta IV Heavy rocket thundered into the pre-dawn darkness, thrilling onlookers for miles around as it climbed through a clear, star-studded sky.

NASA needed the mighty 23-storey rocket, plus a third stage, to get the diminutive Parker probe — the size of a small car and well under a ton — racing toward the sun.

From Earth, it is 150 million kilometres to the sun, and the Parker probe will be within 4 per cent of that distance at its closest.

That will be seven times closer than previous spacecraft.

“Go, baby, go!” project scientist Nicola Fox of Johns Hopkins University shouted at lift-off.

It was the first rocket launch ever witnessed by Parker, professor emeritus at the University of Chicago.

“I really have to turn from biting my nails in getting it launched, to thinking about all the interesting things which I don’t know yet and which will be made clear, I assume, over the next five or six or seven years,” Mr Parker said on NASA TV.

NASA’s science mission chief, Thomas Zurbuchen, was thrilled not only with the launch, but Mr Parker’s presence.

“I’m in awe,” Mr Zurbuchen said. “What a milestone. Also what’s so cool is hanging out with Parker during all this and seeing his emotion, too.”

Parker, the probe, will start shattering records this fall.

On its very first brush with the sun, it will come within 25 million kilometres, easily beating the current record of 43 million kilometres set by NASA’s Helios 2 spacecraft in 1976. Zurbuchen expects the data from even this early stage to yield top science papers.

By the time Parker gets to its 22nd, 23rd and 24th orbits of the sun in 2024 and 2025, it will be even deeper into the corona and travelling at a record-breaking 690,000 kilometres per hour.

With this first-of-its-kind stellar mission, scientists hope to unlock the many mysteries of the sun, a commonplace yellow dwarf star around 4.5 billion years old.

Among the puzzlers: Why is the corona hundreds of times hotter than the surface of the sun and why is the sun’s atmosphere continually expanding and accelerating, as Mr Parker accurately predicted in 1958?

“The only way we can do that is to finally go up and touch the sun,” Mr Fox said.

“We’ve looked at it. We’ve studied it from missions that are close in, even as close as the planet Mercury. But we have to go there.”

The spacecraft’s heat shield will serve as an umbrella, shading the science instruments during the close, critical solar junctures.

Sensors on the spacecraft will make certain the heat shield faces the sun at the right times. If there’s any tilting, the spacecraft will correct itself so nothing gets fried.

“We’ve had to wait so long for our technology to catch up with our dreams,” Mr Fox said.

“It’s incredible to be standing here today.”

More than 1 million names are aboard the spacecraft, submitted last spring by space enthusiasts, as well as photos of Mr Parker, the man, and a copy of his 1958 landmark paper on solar wind.

“I’ll bet you 10 bucks it works,” Mr Parker said.