The Parker Solar Probe, which touched the Sun, has been successfully launched and is fearlessly heading towards the Sun.
The Sun is the main body of the solar system, constantly emitting light and heat. The temperature of the Sun's surface alone is about 5,500 degrees Celsius, and the temperature at its center reaches an astonishing 20 million degrees Celsius, and the temperature of the corona is about 5 × 106 degrees Celsius, the surface temperature is about 6,000 ° C. At such a high temperature, all substances can exist only in the gaseous state.
And this time, Parker will travel deeper into the solar atmosphere than on any previous mission. This is the coronal region, because in the coronal region one can understand what is driving a huge amount of particles, energy and heat through this region, throwing particles out into the solar system, even far beyond the reach of Neptune. Of course, the temperature inside the corona is also unimaginably high. When bombarded with intense sunlight, the spacecraft will travel through material that is in excess of 1 million degrees Fahrenheit. So the question is: at such a high temperature, how can Parker prevent it from scalding and melting?
When it's hot, start with Parker's Magic Shield. The heat shield used by the Parker Solar Probe, known as the Thermal Protection System or TPS, sits on top of a large titanium frame heatsink about 8 feet (2.4 meters) in diameter and about 4.5 inches (115 millimeters) thick. . Those few inches of protection mean that on the other side of the shield, the spacecraft's hull would be at a comfortable 85 degrees Fahrenheit (30 degrees Celsius). The shield is supposed to be built using advanced carbon-carbon technology, which, in simple terms, is carbon composite foam sandwiched between two carbon panels. This lightweight insulation is paired with white ceramic paint on the solar panels to reflect as much heat as possible. Tested to withstand temperatures up to 3000 degrees Fahrenheit (1650 degrees Celsius), the TPS can withstand whatever heat the sun throws at it, keeping just about any tool safe. This structure keeps the spacecraft's payload in a cool dark shadow, allowing it to float freely while Parker's shield is in the spacecraft's path to the sun's surface. Of course, not all Solar Parker tools fall behind TPS for corona data collection.
For example, the solar probe cup protruding from the heat shield is one of two Parker Solar Probe instruments that are not protected by the heat shield. An instrument known as a Faraday cup is a sensor used to measure the flow of ions and electrons, as well as the angle of airflow from the solar wind. Due to the strength of the sun's atmosphere, unique methods had to be developed to ensure that not only the instruments survived, but the onboard electronics gave accurate readings. The bowl itself is made from a titanium-zirconium-molybdenum (titanium, zirconium, molybdenum) alloy called molybdenum alloy, which has a melting point of about 4260 F (2349 C). The grid generating solar electric field detection cup is made of tungsten and its melting point reaches 6192 F (3422 C). The grid lines of these grids are laser engraved and replaced with high melting acids. Then some people may ask: the temperature of the corona is so much higher than the temperature that these structures are exposed to, how can it not melt? It's about to mention another scientific common sense!
This is the relationship between heat and temperature. In real life, high temperatures do not always result in the actual heating of another object.
In space, the temperature can reach thousands of degrees, but the object does not heat up or heat up. Why? Temperature is a measure of how fast particles are moving, while heat measures the total energy they transfer. Particles can move quickly (high temperature), but if there are very few of them, they don't transfer much energy (low heat). Since space is mostly empty, there are very few particles that can transfer energy to a spacecraft. The corona that the Parker Solar Probe passes through is very hot but very low density. The difference between wanting to put your hand in front of a smoking stove and putting it in a pot of boiling water (be careful not to try lightly!), such as an oven whose inner wall is 3 million degrees plasma, if you put your hand into it without touching the inner wall , then it withstands significantly higher temperatures than water, because there are more particles in water. Similarly, the corona is less dense than the visible surface of the Sun, so spacecraft interact with fewer hot particles and don't receive as much heat. This means that while the Parker Solar Probe will fly in space where the temperature is millions of degrees, the surface of the heat shield facing the sun will only heat up to about 2500 degrees Fahrenheit (about 1400 degrees Celsius).
Therefore, the scientists and engineers who designed the spacecraft were more concerned that the spacecraft's scientific instruments and equipment would freeze rather than melt during the mission. To avoid this, the outer surfaces of appliances and equipment are wrapped in thermal blankets and connected to individual solar heaters.
Another problem is related to electronics: most cables can melt under the influence of thermal radiation so close to the sun. To solve this problem, the team grew sapphire glass tubes for hanging wires and used niobium to make them.
Several other spacecraft designs insulate the Parker Solar Probe from heat. Solar panels can overheat without protection. Solar panels power the spacecraft using the energy of the star being studied. Each time it approaches the sun, the solar array shrinks behind the heat shield's shadow, leaving only a small portion exposed to the intense sunlight. Parker solar panels, for example, have a surprisingly simple cooling system: a heated water tank to keep the coolant from freezing during startup, two radiators to keep the coolant from freezing, aluminum fins to increase the cooling surface, and pumps to circulate the coolant. agent. This cooling system is powerful enough to cool a medium-sized living room, and the solar panel and tools need to be cooled and run in the sun.
The refrigerant used in the system is approximately one gallon (3.7 liters) of deionized water. While there are many chemical refrigerants, the range of temperatures a spacecraft is exposed to ranges from 50 degrees Fahrenheit (10 degrees Celsius) to 257 degrees Fahrenheit (125 degrees Celsius). To keep the water from boiling at higher temperatures, the water is pressurized above 257°F (125°C).
Another problem with securing any spacecraft is how to contact it. Parker Solar Probe will be mostly solo travel. Light takes eight minutes to reach Earth, which means that if engineers had to control the spacecraft from Earth, it would be too late by the time something goes wrong.
So the spacecraft is designed to automatically keep itself safe and revolve around the Sun. Several sensors about half the size of a mobile phone are attached to the spacecraft's body along the edge of the heat shield's shadow. If the sensors detect sunlight, they alert the central computer and the spacecraft can adjust its position, keeping the sensors and other instruments safe. All of this needs to happen without any human intervention, which is why the central computer software has been programmed and extensively tested to ensure all fixes are made on the fly.
After launch, Parker will check the position of the sun, point the heat shield at the sun, and continue its journey for the next three months, scientists say. During the planned seven-year mission, the spacecraft withmakes 24 revolutions around the solar star. Each time it approaches the sun, it will collect solar wind samples, study the solar corona, and provide unparalleled observations near the Sun. Of course, Parker has a number of innovative technologies to keep you cool.