Ouch! How NASA finally set out to 'touch' the Sun
Back in 1997, American rock band, Smash Mouth, debuted with a song that went on to become, well, a smash hit — "Walkin' on the Sun". The song was basically a social and racial battle cry.
Two decades later, just around the time NASA was abuzz with its historic mission to touch the Sun — Parker Solar Probe, Gizmodo.com asked scientists: "Why is 'Walkin’ on the Sun' actually pretty timely right now, scientifically speaking?"
This is what Scott Mcintosh, Director of NCAR’s High Altitude Observatory, had to say:
"The Parker Solar Probe is going to be the first piece of human engineering to get that close to the sun. It’s gonna actually touch the sun’s corona. It’ll be cool! Actually, it won’t be cool, it’ll be hot."
The next question was:
"So you mean Grammy-nominated recording artists Smash Mouth lied? You can’t actually walk on the Sun?"
Mcintosh's asnwer:
"There’s no bloody surface of the sun! It’s not possible because there’s no literal surface."
On Sunday, August 12, NASA launched the Parker Solar Probe, a mission to "touch the Sun". The robotic craft will fly closer to the Sun than any man-made object has ever been before, sending back new data on the Sun and the atmospheric conditions around it.
Sunday's launch came after a failed attempt the previous day, when a last-minute alarm caused the US space agency to miss its 65-minute weather window.
Almost an hour after the launch, Nasa confirmed that the spacecraft had successfully separated and the probe had been released into space.
The project is named in honour of American physicist Eugene Parker. Interestingly, this is the first time the space centre has honoured a living person. Dr Eugene Parker, is a 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".
'Touching' the Sun
According to the NASA website, the Parker Solar Probe's path through the corona — the Sun's outer atmosphere — will allow it to observe the acceleration of the solar wind that Parker predicted, just as it makes a critical transition from slower than the speed of sound to faster than it.
A Reuters report said the spacecraft, which is about the size of a small car — it weighs a mere 1,400 pounds — is set to fly into the Sun’s corona within 3.8 million miles (6.1 million km) of the solar surface, seven times closer than any other spacecraft.
“That’s a relatively light spacecraft,” according to Andy Driesman, project manager for the mission at the Johns Hopkins Applied Physics Lab. “And it needs to be, because it takes an immense amount of energy to get to our final orbit around the Sun.”
The spacecraft reportedly will endure extreme heat while zooming through the solar corona to study the Sun’s outer atmosphere that gives rise to the solar winds.
“Eight long years of hard work by countless engineers and scientists is finally paying off,” the NASA website quoted Adam Szabo, the mission scientist for Parker Solar Probe at the Goddard Space Flight Center in Greenbelt, Maryland.
The spacecraft — nestled atop a United Launch Alliance Delta IV Heavy, one of the world’s most powerful rockets, with a third stage added — blasted off toward the Sun with a whopping 55 times more energy than is required to reach Mars.
Describing its speed, the website said, the Parker Solar Probe, zooming through space in a highly elliptical orbit, will reach speed of up to 430,000 miles per hour — fast enough to get from Philadelphia to Washington, D.C., in a second — setting the record for the fastest spacecraft in history.
During its lifetime, under seven years, Parker Solar Probe will complete 24 orbits of the Sun — reaching within 3.8 million miles of the Sun’s surface at closest approach.
“We’ll be going where no spacecraft has dared go before — within the corona of a star,” according to project scientist Nicky Fox of APL.
“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.”
But getting so close to the Sun requires slowing down — for which Parker will use the gravity of our neighbour planet, Venus (See image above. Credit: NASA/JPL/WISPR Team).
Too hot to handle
The real challenge while orbiting this close to the Sun is to keep the spacecraft from burning up.
According to Szabo, "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.
"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.”
According to NASA officials, engineers added a heat shield made of a 4.5-inch thick carbon composite foam material between two carbon fiber face sheets to keep the instruments at the "relatively comfortable temperature" of 85 degrees Fahrenheit (29.4 degrees Celsius).
"No human-made object has ever gone as close to the sun as this mission plans to go, and if the Parker Solar Probe succeeds, it will travel to within 4 million miles (6.4 million kilometres) of the sun's blazing surface, where temperatures reach 2,500 degrees F (1,371 degrees Celsius)," NASA officoals earlier said in a statement.
All aboard
But what would interest you more is that scientists aren’t the only ones "aboard". The spacecraft has a microchip carrying the names of more than 1.1 million participants who signed up to send their name to the Sun. The NASA earlier invited people around the world to submit their names online to be placed on the microchip aboard the historic Parker Solar Probe mission. So all these names have already begun their journey to the centre of the solar system.
Three months later, Parker Solar Probe will reach its first close approach of the Sun in November 2018, and will send the data back in December.
“For scientists like myself, the reward of the long, hard work will be the unique set of measurements returned by Parker,” said Szabo.
“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.”
By the way, when Smash Mouth was asked what does it "think would happen if a person actually walked on the Sun", this is how it had reponded:
Cool enough!
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