NASA is preparing to launch a historic "Touch of the Sun" probe in early August, which scientists hope will solve decades of mystery around our star.
The mission, the so-called Parker Solar Probe, is looped 24 times around the sun and flies in the million-degree atmosphere of the star, the so-called Corona.
The spaceship's daunting schedule is not just a daring lark; it is a necessity to answer questions about the sun that have puzzled scientists for decades. In some cases, their answers will affect our lives on Earth. But scientists also take advantage of convenient access to the Sun to understand all stars through proxies.
"We need to go to the corona because we did so much science by looking at the star," says project scientist Nicola Fox Solar Scientist at Johns Hopkins University, said on July 20 during a NASA press conference about the upcoming mission. "We looked at it in every way you can imagine, at any wavelength, we even left the orbit of Mercury behind, but we need to get into that action region and into the region where all those mysteries are really are occurring. "[New Look Inside Sun̵
Solving Three Secrets
First, the mission will help scientists understand the corona itself – especially how heat moves through the solar atmosphere. Right now, this heat flux seems contradictory: the corona can reach temperatures about 300 times hotter than the surface of the sun, although it is further from the star's reactions.
"It's a very strange, unfamiliar environment for us." Alex Young, a solar scientist at NASA, said during the press conference. "We're used to the fact that when I stand next to a campfire and I go away, it gets cooler – but that does not happen on the sun."
The second purpose of the probe is to study what scientists call the solar wind – a flood of highly charged particles that flows out of the sun and traverses the entire solar system and forms the bubble that marks our neighborhood of space.
But scientists are still working on understanding exactly how it works, and again something very strange happens – the solar wind somehow accelerates to supersonic. "The solar wind goes from a steady breeze to an actual supersonic flow from the corona, which reaches millions of miles per hour," said Young. Scientists hope the probe's measurements, if they fly directly into the solar wind as well as along its current, will help them to solve this mystery.
Eventually, the probe will investigate an even more dramatic episode of life near our star, which occasionally erupts node plasma into space. "The sun can blow up these huge lumps of material – billions of tons of solar atmosphere associated with the sun's magnetic field and flying away from the sun millions of miles an hour," said Young.
These tantrums cause an accumulation of phenomena scientists Call the space weather, and if they are dramatic enough, the outbursts can be dangerous to astronauts and satellites on their way – and the power grids can destroy particularly strong ones here on earth. Scientists have some techniques to predict the space weather equivalent of tornadoes and hurricanes, but they hope the mission will make these predictions more precise.
And if you are here just because of the beautiful pictures, do not worry; NASA has also arranged some of them. The probe contains a camera that shows project scientists the view of the spacecraft through the corona. This does not mean images of the sun's surface, but of the corona itself, with images more similar to those on Earth during a total eclipse. [Watch the Sun’s Elusive Corona Appear in Time-Lapse Solar Eclipse Video]
Scientists have been studying these issues for decades, but without the resources to actually reach for the stars. But they had to wait for the technology to make the Parker Solar Probe a reality.
The most important part of this technology is the heat shield to which most of the spacecraft's tools rely as protection against the dizzying heat of the sun. It's a strangely shaped, unimpressive-looking panel of carefully engineered carbon materials, but it does its job: When the temperatures on the front of the sign reach 1370 degrees Celsius (2500 degrees Fahrenheit), its back is only 600 degrees Fahrenheit (315 degrees Celsius) )) – and the instruments themselves stay at mild 85 ° F (30 ° C).
The spacecraft's instruments are powered by solar panels, but these must be adjusted to handle the overpowering input so close to the sun. "Solar cells need to stay cool, they do not want to overheat, and if they do, they will not work," Fox said. This meant constructing self-cooling panels that the spacecraft can adjust itself, with most of the panels stowed behind the heat shield as needed.
A third important advance was to make sure that the probe could take care of itself without much human intervention. The probe is on the other side of the sun when it's closest, and has no way to call home if something goes wrong – and even if a signal is triggered, a 16-minute communication delay will occur.
"I like to think of her [Parker] as an independent spaceship," said Fox. "She is highly autonomous, she has to take care of herself when she is in this coronal region, there is no person in the loop." This means that the spacecraft can automatically determine when to move its position in space based on how much sun individual parts of the spacecraft receive. [Touching the Sun: NASA Mission Renamed ‘Parker Solar Probe’]
The Parker Solar Probe is located at NASA's Kennedy Space Center, packed and ready for takeoff, despite minor issues delaying the launch by a week, including the addition of a second backup set from temperature sensors the original set would fail.
Now the spaceship is ready to go. "We've done all the work, all the checks, and it looks exactly as I expected from the PowerPoint presentations I saw ten years ago," Fox said. "She's buttoned, looks gorgeous, and is totally ready to make her flight."
The spacecraft is now scheduled for a launch window, which opens at 4:08 pm EDT (0808 GMT) on August 6th and closes on August. 19. It will leave the Earth on board a United Launch Alliance Delta IV rocket with two stages, and a third stage of acceleration will be launched in space.
All this power is necessary to set the spaceship's path to the sun. "We have to go so fast because we have to lose the Earth's influence," Fox said. "We do not want to travel around with the earth, we want to go to the sun."
As soon as the spacecraft escaped Earth's gravity, it flies to Venus about six weeks after takeoff to slow down and get home to the sun. Then it is in the sun. The probe will make 24 orbits around the Sun, interspersed with six other adjustments that use Venus's influence to bring the probe closer to the star.
The orbits are shaped like petals, with the probe collecting most of its data in 11 – the day fires while it is a quarter of the distance to Earth and then sends that information home during the remainder of its loop , During its shortest approach, at a speed of 430,000 mph (700,000 km / h), the probe will travel only 3.83 million kilometers (6 million kilometers) over the sun's surface, making it the fastest man-made object.
Finally, about seven years after launch, the spacecraft will run out of fuel, which it uses to stop its body and keep sensitive instruments away from the sun's heat. And that will be the beginning of the end of the Parker Solar Probe.
"At this point, parts of the body that are not designed to see the full solar environment will then see it, and the spacecraft will begin to divide into large pieces, and then it will gradually and gradually become smaller", Fox said. "I think it's romantic that she's going to be part of the corona and orbiting the sun forever."