LAST UPDATE | 11 Aug 2018
NASA HAS POSTPONED its much-hyped probe launch, one destined to investigate the Sun, after a last minute technical hitch just moments before the launch was due to take place.
The early morning launch countdown was halted with just one-minute, 55 seconds remaining, keeping the Delta IV rocket on its pad with the Parker Solar Probe.
Rocket maker United Launch Alliance said it would try again tomorrow, provided the helium-pressure issue can be resolved quickly. As soon as the red pressure alarm for the gaseous helium system went off, a launch controller ordered, “Hold, hold, hold”.
Once on its way, the Parker probe will venture closer to our star than any other spacecraft. The $1.5 million mission is already a week late because of rocket issues. Saturday’s launch attempt encountered a series of snags; in the end, controllers ran out of time.
The next launch window opens at 8.31am Irish time tomorrow.
Thousands of spectators gathered in the middle of the night to witness the launch, including the University of Chicago astrophysicist for whom the spacecraft is named. Eugene Parker predicted the existence of solar wind 60 years ago. He’s now 91 and eager to see the solar probe soar. He plans to stick around at least another few days.
NASA had been counting down to the launch of the $1.5 billion spacecraft that aims to plunge into the Sun’s sizzling atmosphere and become humanity’s first mission to explore a star.
The 65-minute launch window opened at 7:33am Irish time, with the weather forecast 70% favorable for takeoff, NASA said.
By coming closer to the Sun than any spacecraft in history, the probe’s main goal is to unveil the secrets of the corona, the unusual atmosphere around Sun.
Not only is the corona about 300 times hotter than the Sun’s surface, it also hurls powerful plasma and energetic particles that can unleash geomagnetic space storms, wreaking havoc on Earth by disrupting the power grid.
But these solar outbursts are poorly understood.
“The Parker Solar Probe will help us do a much better job of predicting when a disturbance in the solar wind could hit Earth,” said Justin Kasper, one of the project scientists and a professor at the University of Michigan.
‘Full of mysteries’
The probe is protected by an ultra-powerful heat shield that is just 4.5 inches thick (11.43 centimeters).
The shield should enable the spacecraft to survive its close shave with the center of our solar system, coming within 3.83 million miles (6.16 million kilometers) of the Sun’s surface.
The heat shield is built to withstand radiation equivalent up to about 500 times the Sun’s radiation here on Earth.
Even in a region where temperatures can reach more than a million degrees Fahrenheit, the sunlight is expected to heat the shield to just around 2,500 degrees Fahrenheit (1,371 degrees Celsius).
Scorching, yes? But if all works as planned, the inside of the spacecraft should stay at just 85 F (29 C).
The goal for the Parker Solar Probe is to make 24 passes through the corona during its seven-year mission.
“The sun is full of mysteries,” said Nicky Fox, project scientist at the Johns Hopkins University Applied Physics Lab.
“We are ready. We have the perfect payload. We know the questions we want to answer.”
91-year-old namesake
The tools on board will measure the expanding corona and continually flowing atmosphere known as the solar wind, which solar physicist Eugene Parker first described back in 1958.
Parker, now 91, recalled that at first, some people did not believe in his theory.
But then, the launch of NASA’s Mariner 2 spacecraft in 1962 – becoming the first robotic spacecraft to make a successful planetary encounter – proved them wrong.
“It was just a matter of sitting out the deniers for four years until the Venus Mariner 2 spacecraft showed that, by golly, there was a solar wind,” Parker said earlier this week.
He added that he is “impressed” by the Parker Solar Probe, calling it “a very complex machine.”
Scientists have wanted to build a spacecraft like this for more than 60 years, but only in recent years did the heat shield technology advance enough to be capable of protecting sensitive instruments, according to Fox.
Tools on board will measure high energy particles associated with flares and coronal mass ejections, as well as the changing magnetic field around the Sun.
“We will also be listening for plasma waves that we know flow around when particles move,” Fox added.
And last but not least, we have a white light imager that is taking images of the atmosphere right in front of the Sun.
When it nears the Sun, the probe will travel rapidly enough to go from New York to Tokyo in one minute – some 430,000 miles (700,000 kilometers) per hour, making it the fastest human-made object.
With AP
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