How close can we get to the sun? Robert Goddard created the world’s first liquid-fueled rocket in 1926, the Soviet Union launched an artificial Earth satellite in 1957, and about five years later, Yuri Gagarin became the first man getting into space. Sometime in the late 1960s, the world watched Neil Armstrong and Buzz Aldrin walk on the moon. And then, Voyager 1, launched in 1977, reached Saturn and its largest satellite, Titan. After that it moved further and further away from the sun. Thirty years after its launch, our gaze on the universe is extending more and more frequently to the farthest reaches of the solar system and possibly beyond. But now NASA is focusing its gaze on a burning, glowing ball, which could protect all life on Earth.
So how close can we actually get to the sun? In terms of distance, it is more likely to achieve reaching to a star than escaping the solar system. But the real situation is the opposite. It’s a question about gravity, the fundamental force that drags all objects into the core of the Sun. But the Earth, and every planet, will not fall into such a fiery tomb. This is because they are in orbit around the sun, spinning fast enough to theoretically counteract this pull. In real life, it makes easier for vehicles to travel toward the outside, due to the speed of the orbit tending to be toward the outside of the orbit.
In order to fly toward the sun, however, each nozzle lock of the probe would need to eject gas at the same speed as the Earth’s orbital velocity of 19 miles per second in its orbit, while ejecting in the opposite direction of the Earth’s motion. But this is an almost impossible at the moment, which makes things quite complicated. And getting the probe launched and keeping it in orbit are tricky tasks. If these tasks can be perfect solved, that doesn’t mean things will be easy once the journey begins.
Scientists and engineers had to design the most advanced system, one that could withstand the enormous energy of the sun while traversing the 150 million kilometers between Earth and the center of the solar system. The distance is also known as an astronomical unit, which is by no means an insignificant length, and the route was definitely not directly to the sun. But we have now done much more than that, with Voyager 1 flying more than 140 astronomical units which break the record. At this point Voyager 1 has headed into the mysterious future, but any spacecraft flying toward the sun is heading toward something we already know. However, most of what we know now doesn’t allow us to find a solution to solve the problem of high temperatures when the spacecraft gets close to the sun.
The sun has a radius of nearly 700,000 kilometers and is made up of several circles, and how hot is it exactly? The temperature varies greatly from the different circles of the Sun, but there is no doubt that the core region is the hottest part, where temperatures can reach about 28 million degrees Fahrenheit. The closer you get to the surface of the Sun, the faster the temperature drops, and by the time you reach the photospheric layer of the Sun’s atmosphere, the temperature plummets to about 10,000 degrees Fahrenheit. According to this principle, the temperature of the outermost layer of the solar atmosphere – the corona – should be the lowest. However, in fact the opposite is true, the temperature of the corona can easily rise to millions of degrees Fahrenheit. Researchers speculate that the cause of this phenomenon is most likely caused by millimeter flares, which are small but can produce violent thermal explosions that release large amounts of energy into the atmosphere.
At the same time the corona releases charged particles in the form of solar wind, which can disrupt the Earth’s magnetic field and damage the electrical system. All this means that our attempts and explorations of the Sun are not always smooth and face increasing dangers. In fact, there is potentially a pending task to be solved on all aspects, including better explore both the multiple unsolved mysteries surrounding the Sun’s upper atmosphere and its tangible impact on our daily lives – the melting of probes at high temperatures. NASA believes it’s time to use the Parker Solar Probe to solve these mysteries before 2018. 1976 saw the closest recorded flight of the Helios probe to the Sun at about nine astronomical units or 43 million kilometers from its target, which is an event that helped us to study the solar wind and cosmic rays.
Parker Solar Probe, NASA’s recently launched, has already broken Helios’ record. Their ultimate goal is to make it the first man-made device to touch the sun. Parker’s mission is simple: enter the sun’s upper atmosphere and collect data, which helps to investigate the mechanisms behind the formation of the solar wind. It’s a noble act of exploration, but how does Parker plan to achieve its goals? We know that the technology to fly directly to the Sun does not exist yet, so the plan to touch the Sun’s surface is not feasible. The probe is simply set to enter the corona and fly as close to the Sun as possible with the help of planets or astronomical objects, and a gravitational slingshot will help change the probe’s direction and speed as well as constantly reducing fuel so that it can reach the Sun. Parker’s flight route will periodically pass by Venus, and plan seven flybys to pass it. During that period, the probe will usually use the momentum generated by some of the planets to provide substantial speed boost and steering to the probe itself.
In October 2018, the Parker Solar Probe will be able to break the record set by Apollo II and will complete its mission to Mercury in 2025. “The Parker Solar Probe will reach the central star at more than twice of the speed, which is 6.5 million kilometers away. The gravity helps solve NASA’s problems about momentum and distance, but it also has a problem about the temperature of the corona that will melt the Parker Solar Probe faster than ice cream on a hot summer day.
First, there is the difference between temperature and heat. Temperature refers to the rate of motion of particles. This means that if there are few or almost no particles around, any particles around it are related to the transfer of energy between particles. So even if the coronal layer is ridiculously hot, as long as the atmospheric density is low it means that less energy is transferred and less heat is generated. On Earth, this principle explains why people can comfortably sit in a sauna with a temperature comparable to or higher than that of boiling water. So even though the Sun’s atmosphere may be a million degrees Celsius, the Parker Solar Probe only needs to withstand several thousand degrees of heat. The corona is still very hot, and the probe need to survive from the constant onslaught for nearly seven years.
If he really succeeds, he will stamp his name on the page of history. The cost of building “Parker” solar probe is up to 1.5 billion dollars due to its innovative Thermal Protection System (TPS). Scientists still hope that it can withstand temperatures of up to 2500 degrees Celsius even without TPS. It’s no exaggeration to say that NASA’s ambitions are still just like science fiction. TPS has a wide range of regulation, which sets the internal temperature at around 85 degrees Fahrenheit, and it weighs is less than the average American’s 160 pounds. It is shaped like a shield and consists of a 4.5-inch thick carbon foam core sandwiched which insert into two bendable carbon sheets. Parker will not melt because the TPS will prevent heat from entering the core of the spacecraft.
Finally, NASA sprayed a white layer of aluminum oxide on the shield, which will protect “Parker” as if the sun’s energy had disappeared from the probe and had almost no effect on “Parker”. But no fuel will sustain Parker for nearly seven years of travel to its destination. The probe has used up its fuel after its first launch, then it will use solar energy to maintain a sophisticated cooling system, and solar panels will support the plan to accelerate the spacecraft through the solar system. Considering its ultimate goal, solar energy should not be too difficult to obtain, as the distance Parker Solar Probe is expected to reach perihelion is the moment when an object is closest to the sun.
The Parker Solar Probe will experience 24 such moments (24 orbits around the Sun) before ending its mission, 2025. Most of the orbits that the Parker Solar Probe passes through in its flight will shorten the distance between it and the Sun. NASA predicts that the closest approach (of the Parker Solar Probe to the Sun) will occur during its 22nd orbit around the Sun at a speed around 400,000 miles per hour, when the distance between the two is expected to be about 6.1 million kilometers, just 0 astronomical units .December 24, 2024 will be an landmark because Parker’s distance to the Sun is only a few million kilometers, which is the closest to the sun human will ever get. The mission to observe and study the Sun will come to an end when Parker makes its final orbit around the Sun. It will gradually disintegrate and become part of the Sun’s atmosphere as it is heated. This is certainly a fitting end for this magnificent technical product.
A spacecraft is a vehicle or machine used to fly in outer space. As a type of artificial satellite, spacecraft have a wide range of uses, including communication, Earth observation, meteorological research, navigation guidance, space colonization, planetary exploration, and human and cargo transportation. With the exception of Single stage to orbit vehicle, all spacecraft cannot go into space on their own and require the use of a movable launcher (i.e., launch vehicle).
In suborbital spaceflight, a spacecraft enters space and immediately returns to the ground because it does not have enough energy or speed to orbit the Earth. In orbital space flight, on the other hand, the spacecraft enters a closed orbit around the Earth or another celestial body.
While vehicles used for manned spaceflight send crews or passengers into orbit (space stations), spacecraft used for robotic space missions operate either automatically or remotely. Robotic spacecraft used for scientific research are called space probes. Artificial satellites, on the other hand, are robotic spacecraft that stay in planetary orbit. So far, only a few interplanetary probes have been able to operate in non-solar orbits, such as Pioneer 10 and 11, Voyager 1 and 2, and New Horizons.
There are orbiting spacecraft that are retrievable but most are irretrievable. Depending on how they re-enter the Earth’s atmosphere, return-type spacecraft can be classified as non-winged or winged. Retrievable spacecraft are reusable (re-launchable or multi-launchable, such as the SpaceX Dragon manned spacecraft) or disposable (such as the Soyuz spacecraft). In recent years, an increasing number of space agencies are tending to build reusable spacecraft.
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- Astronomers divide the solar structure into two major parts: the internal structure and the atmospheric structure. The internal structure can be divided into three parts: the solar core, the radiation layer, and the troposphere; the atmospheric structure can be divided into the photosphere, chromosphere, and corona. The core region of the Sun is small, with a radius of only 1/4 of the Sun’s radius, but it is where nuclear fusion reactions are generated and where the Sun’s energy is located.
- The solar corona, a natural phenomenon, is the outermost layer of the solar atmosphere (the chromosphere and the photosphere, respectively), which is several million kilometers or more thick. Beyond the chromosphere is the corona, which is extremely hot, with a coronal temperature of 1 million degrees Celsius and a particle number density of 10 15/m
- Parker Solar Probe Parker Solar Probe,” a spacecraft named after astronomer Eugene Parker, a pioneer in solar wind science and professor emeritus at the University of Chicago, is the first NASA spacecraft to be named after a living figure. Solar Probe (SP) was the first vehicle to fly into the solar corona.
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