NASA has finally sent a spacecraft on a mission to fly where no probe has ever gone before – into the sun’s scorching outer atmosphere.
The probe took off at 3.31 ET (8.31 BST) this morning. It was initially set to launch at 3.33am ET (8.33am BST) yesterday, but poor conditions meant it was pushed back 24-hours.
The unmanned spacecraft is on an unprecedented quest that will take it straight through the edges of the corona, or outer solar atmosphere, just 3.8million miles from the sun’s surface. Previously, the closest an aircraft had come to the sun was 27million miles.
The $1.5billion (£1.17billion) Parker Probe blasted off atop one of the most powerful rockets in the world.
It will eventually hit record-breaking speeds of up to 430,000 miles per hour as it completes 24 orbits of the sun over the course of seven years. At this speed, it would take two minutes to travel from London to New York.
While orbitting the sun, the craft will swing around Venus seven times, using the planet’s gravity to push it closer and closer to our star with each pass; eventually, the Parker probe will get within 3.8 million miles of the sun’s surface.
It will make its first fly past Venus in October, and is protected by a revolutionary new heat shield.
That will set up the first solar encounter in November.
It will be subjected to temperatures of roughly 2,500 degrees Fahrenheit (1,371C) when it comes closer to the sun than any spacecraft in history – but, behind its thick heat shield, it will only feel like a hot summer day, with this sheltered region maxing out at about 85F (29C).
Yesterday the agency had until 4.38am in Florida (9.38am BST) to take off but a ‘condition’ meant they missed the window, leaving people disappointed around the world as they tuned into the livestream.
‘At this time, our Parker Solar Probe launch team is in a no-go status as we await further details. Teams are investigating a condition.
‘Today’s window opened for liftoff at 3.33am ET and closes at 4.38am ET’ they said.
They later said the vehicle was cleared for launch, and would take off at 4.28am.
But the Parker Solar Probe did not launch from Cape Canaveral until this morning atop a ULA Delta IV Heavy, already one of the most powerful rockets in the world, with a third stage attached.
This mission will require 55 times more energy than would be needed to reach Mars, according to NASA.
The probe will rely on a series of gravity assists from Venus to slow down its sideways motion, allowing it to get just 3.8 million miles away from the sun’s surface.
As NASA engineer Bobak Ferdowsi pointed out on Twitter, that’s the equivalent distance of just 4.43 suns positioned next to each other.
This will put the Parker probe well within the sun’s corona, which extends about 5 million miles above the surface.
‘We’ll be going where no spacecraft has dared go before – within the corona of a star,’ said project scientist Nicky Fox, of the Johns Hopkins Applied Physics Lab.
‘With each orbit, we’ll be seeing new regions of the sun’s atmosphere and learning things about stellar mechanics that we’ve wanted to explore for decades.’
The corona, or the sun’s outer atmosphere, is home to ultra-hot solar material and some of the most extreme events emanating from our star.
Here, material heats up to millions of degrees, NASA says.
Parker Solar Probe’s unprecedented access to the corona will let it study the acceleration of solar wind up close, and observe the solar flares and coronal mass ejections that have rippling effects on space weather and communication systems down near Earth.
The craft is named for Dr Eugene Parker, who first predicted the existence of solar wind back in 1958, and is the only living person to have ever had a NASA mission named for them.
The probe is also towing the names of over 1.1 million people who signed up to have their names sent to the sun.
This and roughly 1,400 pounds of solar projection and science equipment are protected by an advanced heat shield, which uses a 4.5-inch thick carbon composite foam material between two carbon fibre face sheets.
‘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,’ says Adam Szabo, the mission scientist for Parker Solar Probe at NASA’s Goddard Space Flight Center in Greenbelt.
‘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 historic mission will give us the best opportunity yet to study the star that holds up our entire solar system.
And, it’s one of the last places within our stellar neighborhood that has yet to be explored.
‘For scientists like myself, the reward of the long, hard work will be the unique set of measurements returned by Parker,’ Szabo said.
‘The solar corona is one of the last places in the solar system where no spacecraft has visited before. It gives me the sense of excitement of an explorer.’