NASA’s Juno Jupiter probe is about to end its five-year long space flight, and Jupiter Orbital Intrusion (JOI) will be carried out at 11:18 am on July 5th, Beijing time. Thus entering the orbit of the largest planet of the solar system, it becomes its artificial satellite. The "Juneau" detector was launched in 2011 and arrived at Jupiter on July 5, 2016. After launching, the Juno detector used its main engine twice, and started the main engine twice on August 30, 2011 and September 3, 2012. Juno undertakes important scientific observation missions. To achieve the relevant goals, the spacecraft adopts the Jupiter polar orbit and has a very low flying altitude. It needs to fly very low in order to obtain accurate gravitational field measurement data. This track design avoids the most dangerous areas of radiation and maximizes the safety of the spacecraft. Jupiter's radiant band distribution is somewhat similar to the Van Allen radiation band over the Earth, but its intensity is much stronger. During the operation around Jupiter, the Juno detector was only less than 5,000 kilometers away from the top of the Jupiter cloud. It runs around Jupiter every 11 days. The mission is expected to end on February 20, 2018, when the spacecraft will take the initiative. Controlled to fall into the atmosphere of Jupiter and burned. I. Basic information about the Juno mission (1) Naming: The mission was named Juno (JUNO), named after the wife of the god of the gods, Jupiter, and the goddess Juno. The goddess Juno has the power to penetrate the clouds and gain insight into the truth, which is very suitable for the naming of this mission. Scientists hope that the spacecraft will also be able to see through Jupiter's thick atmosphere and clouds, and gain insight into its internal structure. (2) Basic parameters of the spacecraft Spacecraft body: 3.5 meters high and 3.5 meters in diameter (solar windsurfing) Solar windsurfing: Single solar panel size: 9 m X 2.65 m, total light receiving area over 60 square meters, including a total of 18698 solar chip units; total power generation: about 14 kW near the Earth's orbit, near Jupiter's orbit 400 watts; Quality: The launch quality is 3625 kg, including the mass of the spacecraft itself, 1593 kg, 1280 kg of fuel and 752 kg of oxidant. (3) Launching a rocket The Cosmic God V551 rocket, that is, the rocket stage adopts a cosmic god rocket core class, bundles 5 solid propelling rockets, and then configures the upper level of the Centaurus. The total height after carrying the load is about 60 meters. The weight is about 574 tons. (4) Some milestones during the project 1) Time: August 5, 2011 Event: Juno launches into space Launch location: SLC-41 launch pad at Cape Canaveral Air Force Base, Florida, USA; Earth-Jupiter distance at launch: 716 million kilometers, the signal travels at a speed of light requiring 39 minutes and 50 seconds for a single pass; 2) Time: October 9, 2013 Event: Earth Gravitational Slingshot From the Earth to the Earth, the distance of the detector is 1.6 billion kilometers, and the Earth is 500 kilometers away from the ground when flying. 3) Time: July 5, 2016 Event: Entering Jupiter Track When entering the orbit, the distance between Earth and Jupiter is about 869 million kilometers, and it takes 48 minutes and 19 seconds for the signal to travel one-way at the speed of light. From launch to into Jupiter's orbit, the detector's flight distance: 2.8 billion kilometers; 4) Time: February 2018 Event: End of mission (5) Project investment The Juno project has a total investment of approximately US$1.1 billion, including detector development, scientific payloads, launch services, operating expenses, scientific data processing, and measurement and control support. Second, the basic situation of the detector Juno is a spin-stabilized solar spacecraft designed with a large elliptical orbital scheme to avoid Jupiter's powerful radiation belt. The design idea of ​​the whole project is to adopt mature technology. All the projects use off-the-shelf scientific equipment, and no new research and development technologies are needed. 1) Why use spin stabilization design? For Juno, like NASA's early "pioneer" spacecraft, spin will enhance the stability of the spacecraft's pointing and facilitate ground control. During the period from the launch until the solar windsurfing is unfolded, the rotation of the Juno spacecraft will be completed by the upper stage of the rocket still connected to the spacecraft. Juno's rotation speed also changed during the whole project: the rotation rate during the cruise phase was 1 lap per minute, the scientific investigation phase was 2 laps per minute, and the main engine working posture phase was temporarily changed to 5 laps per minute. In order to simplify the design and reduce the quality, all the equipment that Juno is equipped with is fixedly installed. When running around Jupiter, as the spacecraft spins, all equipment will sweep Jupiter through its observation field in a single lap. When the spacecraft was in working condition for 2 laps per minute, the relevant scientific equipment would sweep Jupiter 400 times within two hours of the Juno spacecraft flying over a polar wave from Jupiter to the other end. 2) Propulsion system To control weight and add redundancy, the Juno spacecraft uses a dual-mode propulsion system that includes a main engine with two propellants and multiple position-adjusting engines with a single propellant. A Leros-1b main engine mounted on the Juno spacecraft is a 645 Newton twin propellant engine using a hydrazine-nitrogen tetroxide propellant. Its engine nozzle is fixed at the rear of the detector, and its main function is large track adjustment and deceleration braking. In addition to the main engine, there are 12 smaller thrusting attitude engines on the detector. Their presence makes it possible for the spacecraft to make attitude adjustments in three dimensions, and they are also used for smaller orbit adjustments. 3) Command and data processing The Juno detector's command and data processing system uses a RAD750 flight processor with 256M flash and 128MDRAM local storage. 4) Electronic protection cabin In order to protect sensitive electronic equipment, the Juno spacecraft used the radiation protection electronic cabin for the first time. This design will be of value for future exploration projects that also perform tasks in high-intensity radiation environments. The radiation-proof electronic compartment made of titanium is about the size of the trunk of an SUV-type sedan, and its protective layer is more than 1 cm thick. The spacecraft's command and data system (equivalent to the detector's brain), the power and data distribution system (equivalent to the heart) and about 20 other electronic devices are installed, and the entire electronic cabin weighs more than 200 kilograms. 5) Solar power generation Jupiter is five times farther away from the Sun than the Earth, so the solar power received near Jupiter is only about 1/25 of that near Earth. Juno will be the first solar-powered spacecraft to be used at such a long distance, so the solar windsurfing area of ​​the Juno spacecraft must be as large as possible in order to generate enough power. Juno’s daring to adopt such a bold approach has benefited from a 50% increase in power generation efficiency in solar panels over the past 20 years. In addition, according to the design, the power consumption of the Juno spacecraft itself is very low, which is an energy efficient spacecraft. The three solar panels of the Juno spacecraft extend from its hexagonal body, making the spacecraft after the solar panels unfolded more than 20 meters wide. These solar panels are deployed in space until the end of the mission, and will remain in the right direction for the sun, except for a few minutes during the flight. Of course, like other spacecraft, in order to be able to fit into the rocket fairing, the solar panels are folded when launched. Third, the scientific load of the Juno spacecraft The load carried by the Juno spacecraft includes 29 susceptors that transmit data to nine loads. Eight of the scientific payloads—including MAG, MWRz, Gravity Science, WAVES, JEDI, JADE, UVS, and JIRAM equipment—are classified as scientific payloads; the last JunoCam camera is primarily a payload for educational and publicity purposes. . Because Juno uses a large elliptical orbit, it is sometimes far away from Jupiter and sometimes very close, so most scientific exploration missions will be in orbit within approximately 3 hours of Jupiter. Performing, of course, in other locations on the orbit, calibrations, some long-range observations, and magnetic field detection are also performed. 1) Gravity Science - Gravity Science Load The Gravity Scientific payload will give the Juno detector the ability to detect Jupiter's gravitational field, and we will explore the internal structure of Jupiter. The two transponders installed on the Juno detector operate in the X-band and Ka-band, respectively, and are capable of receiving signals from the Earth's Deep Space Network (DSN) system on Earth to the spacecraft and immediately returning a corresponding response to the Earth. signal. When these return signals arrive at Earth, ground scientists will analyze the signal frequencies. These signals will show a slight frequency change due to the local differences in Jupiter's gravitational field. This change reflects the difference in Jupiter's internal structure. Ka-band transponder equipment is provided by the Italian Space Agency. 2) Magnetometer: magnetometer The magnetometer will allow the Juno spacecraft to draw a detailed three-dimensional structure of the Jupiter magnetic field. The magnetometers on the Juno spacecraft are a type of fluxgate detector that detects the strength of the Jupiter magnetic field and the direction of the magnetic line. The "Advanced Star Navigator" that comes with the system will provide the system with information on the orientation of the magnetometer itself. Like other detectors, the Juno spacecraft's magnetometer equipment is mounted on top of one of the three extended solar panels to keep it as far away as possible from the ship's body. This is mainly to avoid the magnetic field generated by the spacecraft's other equipment working to interfere with the measurement of the Jupiter magnetic field signal by the magnetometer. In addition, in order to further correct the possible interference of the spacecraft's own equipment on the measurement of Jupiter's magnetic field signal, Juno installed two magnetometers, one about 10 meters away from the spacecraft body and the other about 12 meters. By comparing the data obtained by the equipment, the scientists were able to accurately remove the interference signals from the spacecraft equipment. Juno's magnetometer equipment was designed and built by NASA's Goddard Space Flight Center, while the "Advanced Star Navigator" equipment was designed and manufactured by the Danish Technical University. 3) MWR - microwave radiometer Juno's microwave radiometer equipment will penetrate the clouds of Jupiter, revealing the structure, composition and movement of its deep atmosphere. Its maximum penetration depth can reach the depth of 1000 times atmospheric pressure on the earth, which is equivalent to about 550 kilometers from the top of the Jupiter cloud. The microwave radiometer system consists of six independent radiometers for measuring microwave signals from six different layers of clouds. Each radiometer has an antenna that extends outwardly from the hexagonal body of the spacecraft body. Each such antenna is connected to a data line and finally to a receiver inside the electronic compartment. The device was designed and manufactured by NASA's Jet Propulsion Laboratory (JPL). 4) JEDI - Jupiter High Energy Particle Detector The Jupiter High Energy Particle Detector detects high-energy particles in space and observes their mutual lease with the Jupiter magnetic field. The JEDI device consists of three identical susceptors, each with six ions and six electronic observation channels. The device will work in conjunction with the microwave radiometer and the JADE (Jupiter Aurora Distribution Experiment) equipment to detect conditions over the Jupiter polar region, with particular attention to Jupiter's strong and distinct North and South lights. The equipment was designed and manufactured by the Johns Hopkins University Applied Physics Laboratory (APL). 5) JADE - Jupiter Aurora Distribution Experiment The Jupiter Aurora Distribution Experiment facility will work with some of the other equipment that Juno is equipped to study the particle motion and mechanism that causes Jupiter's aurora to produce. The Jupiter Aurora Distribution Experiment equipment consists of an electronic cabin with four susceptors, three of which are used to detect electrons in the environment surrounding the spacecraft, and the fourth is used to identify positively charged hydrogen, helium, oxygen and sulfur. Ions of other elements. When the detector flies over Jupiter's aurora, these devices will be able to identify the types of particles that rush into the atmosphere above the Jupiter's polar region. This equipment was designed and manufactured by NASA Southwest Research Institute. 6) WAVES - plasma electric wave equipment The plasma wave device will measure the radio wave and plasma wave signals inside the Jupiter magnetosphere, which will help us understand the interrelationship between the magnifier field, the atmosphere, and the magnetosphere. The plasma wave device contains a V-shaped antenna with a height of about 4 meters. This equipment was developed and manufactured by the University of Iowa. 7) JIRAM - Jupiter Infrared Aurora Plotter The Jupiter Infrared Aurora plotter will observe the atmosphere around Jupiter's aurora and help scientists understand the relationship between magnetic fields and aurora. The device will be able to detect a depth of about 50 to 70 kilometers below the Jupiter cloud, where the atmospheric pressure is about 5 to 7 times the height of the Earth's plane in Shanghai. The Jupiter Infrared Aurora plotter includes a camera and a spectrometer that splits the light into individual component bands, similar to a prism. The camera will acquire the infrared image, which is the thermal radiation band, and the wavelength range is about 2~5 microns. This wavelength is 3~7 times longer than the visible band. The Jupiter Infrared Aurora Plotter was developed and manufactured by the Italian National Institute of Astrophysics and funded by the Italian Space Agency. 8) UVS - UV imaging spectrometer The UV imaging spectrometer will capture images of the ultraviolet band of Jupiter's aurora. Working with JADE and JEDI devices, they will help scientists understand the interaction between Jupiter's aurora, particle flow and magnetic field. The UV imaging spectrometer consists of two separate sections: a dedicated telescope/spectrometer mounted on a radiation protection electronics bay. The telescope is mainly used to collect light for the spectrometer. The other part is the electronic device part of the device, which is located inside the electronic equipment bay of the spacecraft. The UV imaging spectrometer was developed and manufactured by NASA Southwest Research Institute. 9) JunoCam - Juno Camera The Juno camera will capture a color image of Jupiter in the visible range. The Juno camera will have the ability to capture wide-angle images of Jupiter's atmosphere and polar regions. This device has been designed from the beginning to be a full color camera for public science use. The public will have the opportunity to participate in the process of generating image products from raw data and help select the targets that the camera shoots. The hardware of the Juno camera is based on the descending camera of the American Curiosity Rover. Some of the software used is derived from the code originally designed for the Mars Odyssey and the Mars Reconnaissance Orbiter (MRO). The equipment is provided by Marin Space Science Systems, USA. Fourth, the basic situation of Jupiter "If you put everything in the solar system together (not the sun), they can all be stuffed inside Jupiter." This sentence best reflects Jupiter's most striking feature, that is, big. Jupiter is the most massive celestial body in the solar system (the sun is not counted), and it is named after the "Jupiter", the king of the gods in Roman mythology. As early as the 17th century, Italian astronomer Galileo observed that Jupiter had four large satellites through early telescopes. These four Jupiter satellites are now collectively called "Galileo satellites." In addition to these four large satellites, Jupiter also has many more than 60 smaller satellites, just like a small miniature solar system. In terms of composition, Jupiter is more like a star, and it is true. If Jupiter's mass is increased by about 80 times, it can become a real star. Observing Jupiter, the most striking thing is its rich color and detailed atmospheric structure. Most of the Jupiter clouds we see are mainly ammonia, and the clouds of water ice are in deeper positions, and occasionally can be observed in some atmospheric cavities. The very obvious "cloud belt" on Jupiter is formed by the strong east-west strong winds in the high-altitude atmosphere. In the middle of such lateral clouds, there are some storm systems, many of which can last for many years, the most famous of which is the Great Red Spot. This huge storm system has been stable for more than 300 years. Just a few years ago, there was another small red spot on Jupiter, about half the size of the big red spot. Jupiter's composition is similar to the sun, mainly hydrogen and helium. As the depth of Jupiter's atmosphere increases, the atmospheric pressure continues to increase and the temperature gradually increases. At a certain depth, hydrogen is compressed into a liquid-like substance. At a depth equivalent to approximately 1/3 of Jupiter's radius, the hydrogen species here have been liquid in extreme high temperature and high pressure environments and can conduct electricity, known as "metal hydrogen." Scientists believe that it is the flow of tumbling motion of this layer of conductive metal hydrogen that produces Jupiter's powerful magnetic field. In the core area of ​​Jupiter, there may be a core made up of heavier metals in an extreme pressure environment that may exceed the entire globe. Jupiter has the most powerful magnetic field in the major planets of the solar system, and its intensity is more than 20,000 times stronger than the Earth's magnetic field. Under the action of a strong magnetic field near Jupiter, a large number of charged particles are trapped in it, forming a violent radiation zone, mainly a large number of electrons and various types of ions. These powerful particle streams continue to bombard Jupiter's moons and halos. The Jupiter magnetosphere extends 1 million to 3 million kilometers in the direction of the sun and more than 1 billion kilometers in the direction away from the sun. On January 7, 1610, Italian scientist Galileo saw Jupiter's four moons using a telescope that looks quite primitive today: Io, Europe, Ganymede, Callisto. Today, these four satellites are called Galileo satellites. According to the latest data, excluding those "temporary" satellites, Jupiter has a total of 64 "official" satellites, ranking first among the major planets in the solar system. The so-called "temporary" satellites mainly refer to asteroids or comets that are temporarily captured by Jupiter's powerful gravitational field due to their proximity to Jupiter. They tend to run around Jupiter for a few days, months or even years, and then leave to continue their original The flight journey, or falling into the Jupiter atmosphere, was burned. There are three thin halos over Jupiter's equator, and their brightness is far less than that of Saturn's aura. The main component of the Jupiter Aura is very fine dust particles, which may be the source of collision between the asteroid and the Jupiter satellite. The Jupiter Aura was first discovered in 1971 by ground-based telescopes and NASA Voyager 1 spacecraft. Jupiter detection memorabilia: 1610: Galileo conducted the first detailed Jupiter observation; 1973: NASA's Pioneer-10 spacecraft became the first human spacecraft to travel through the asteroid belt and fly Jupiter; 1979: NASA's Voyagers 1 and 2 discover a weak aura of Jupiter, several new moons, and an active volcanic eruption on the surface of Io; 1994: Astronomers from around the world and NASA's Galileo probes collide with the comet "Shoemaker-Levy 9" in the southern hemisphere of Jupiter. This is the first time humans have witnessed a celestial collision; 1995: NASA's Galileo spacecraft carries a detector to Jupiter to conduct the first direct detection of the Jupiter atmosphere and a detailed examination of the entire Jupiter system; V. Overview of the scientific goals of the Juno project Jupiter is currently the largest planet in the solar system. People have been trying to study this planet for centuries, but we still have a lot of basic questions to answer about this giant planet. In 1995, NASA's Galileo probe arrived at Jupiter, one of which was to place a small detector in the Jupiter atmosphere. The data it returns shows that the composition of the Jupiter cloud and the atmosphere is different from what scientists had thought before, suggesting that there may be some bias in our relevant theoretical models. Today, under the thick clouds and fierce storms of this huge planet, there are still many hidden mysteries about the life of this huge planet and the history of the entire solar system. Below we only list a small part of us. Basic questions not fully understood: 1) How is Jupiter formed? 2) How much water and oxygen does Jupiter have in the atmosphere? 3) What is the internal structure of Jupiter? 4) Does Jupiter's rotation more closely match the rigid body rotation, or does it have different speeds of rotation at different depths inside? 5) Does Jupiter have a solid-state core? If so, how big is this kernel? 6) How is Jupiter's powerful magnetic field formed? 7) How many atmospheric structures seen at the top of the Jupiter cloud layer extend downwards, and how does it relate to the deep motion of Jupiter's atmosphere? 8) What is the mechanism of Jupiter's aurora production? This time, the main mission of the Juno detector is to examine the formation and evolution of Jupiter. Using proven, proven technology, Juno is equipped with a range of advanced equipment and operates in a polar orbit, detecting Jupiter's gravitational field, magnetic field structure and composition, and observing Jupiter's internal structure, atmosphere and magnetic fields. Inter-related. Through these studies, scientists will deepen our understanding of Jupiter's formation and evolution, and based on this, deepen our understanding of the entire solar system birth process and mechanism. Cable Special For Wind Energy,Spectrum Cable Specials,Infinity Cable Specials,Spectrum Internet Special Prices TRANCHART Electrical and Machinery Co.,LTD , https://www.tranchart-electrical.com