From July 14, 2020, the quasi first kind of space civilization on earth, mankind, has ushered in a window period of Mars exploration and launch. During this window period, a total of three Mars projects have been launched, including China’s most familiar Mars exploration mission tianwen-1, the United States’ Mars 2020 program, and the United Arab Emirates Mars mission. Since mariner 3 was launched in 1964, the United States has carried out nearly 20 successful Mars exploration missions in recent decades. It is a veteran of Mars exploration, and its publicity is mature and vigorous. China, our motherland, tianwen-1, as a milestone for us to enter deep space, has also been the focus of media publicity in the past month. In contrast, the United Arab Emirates Mars program is very few words, few people to introduce propaganda. So today, we will analyze the general contents of the UAE Mars mission through the public information on the Internet. The United Arab Emirates is called UAE for short. The name of the United Arab Emirates Mars mission is quite straightforward, which is Emirates Mars mission, or EMM for short. The mission included a Mars Orbiter, which, after extensive naming exercises, received an equally straightforward name – hope. If the mission is successful, the hope Mars probe will become the first in the Middle East, the first in the Arab world, and the first of all Muslim countries, the Mars probe. < / P > < p > hope is a deep cooperation project between the United Arab Emirates and the United States, Japan and other countries. Before going into more details, I would like to state that Mars exploration is the common scientific cause of mankind. Any country or organization that joins the family of Mars exploration and explores Mars with the main purpose of science should be supported and encouraged. < / P > < p > when we talk about the UAE, we often think of the black gold everywhere, the sci-fi and extravagant Dubai, the super sports cars and luxury villas in different styles, the miracle palm island of reclamation, the list of princes that can’t be written down on a page, and the unique customs and beliefs of the Middle East that are quite different from ours. In many people’s dictionaries, the UAE is generally a synonym for local tyrants, not for the best, but for the most expensive. Palmetto Jumeirah, the earliest and smallest of the three Palm Islands in Dubai, was built in the early 21st century. It’s full of private estates and resort hotels. To build the island, the UAE bought the only private satellite in the world at that time to provide precise positioning planning comparable to that of the US spy satellite. However, we should also know that stereotypes are not desirable. UAE is obviously ambitious in many aspects, but also aware of the potential danger of resource-based single economy, and hopes to develop high-tech industries.
Sheikh Mohammed bin Rashid Al Maktoum, vice president and Prime Minister of the United Arab Emirates, said in his mission plan that EMM is to send three messages to the world: < / P > < p > 1. For the whole world, it sends a message: Arab civilization once played an important role in human history and contributed a lot of knowledge, and now it will play such a role again; < / P > < p > 2. For all Arab countries The cell sends a message: there is nothing impossible in the world. In the competition of knowledge, we can also compete with the most powerful countries on the same stage. < / P > < p > at first glance, these three messages are empty words, but if put in the UAE environment, the language reveals the ambition, it is very straightforward. After talking about politics and looking at science, hope’s scientific mission is much simpler than that of the probes in China and the United States in the same period. The main goal of the mission is to make a complete image of the atmosphere of Mars, including the lower atmosphere and the upper atmosphere. The observation of Mars atmosphere by hope includes the daily and seasonal changes of climate, as well as various meteorological events and their distribution. In the words of the United Arab Emirates, “this will be Mars’s first real weather satellite.”. < / P > < p > hope will help scientists understand the dramatic changes in the atmosphere of Mars – how Mars changed from a planet rich in liquid water to a dry, barren world today? How do hydrogen and oxygen escape from the Martian atmosphere? What is the interaction mechanism between the upper and lower atmosphere of Mars? What’s more, can we deduce the model of earth’s future atmospheric change from the change of Martian atmosphere? < / P > < p > these tasks are relatively specific and require in-depth observation of the atmosphere, so hope is required to carry professional imaging equipment. Next, let’s take a look at the scientific equipment that hope is carrying. < / P > < p > if we want to describe the scientific payloads of the U.S. or China’s Mars mission, we may need a lot of articles to discuss. Both the perseverance Mars rover and tianwen-1 Mars rover belong to the comprehensive scientific platform. For a variety of scientific experimental objectives, they are equipped with various types of instruments with different functions, and each has a very complex working principle. The scientific goal of hope is quite specific, so it only carries three scientific instruments, namely multispectral camera, ultraviolet spectrometer and infrared spectrometer. Note: hope and its main instruments. Note that there is a difference between the concept map and the actual design. The shape changes from a hexagonal prism to a quadrangular prism, and the solar panel into two groups. ① 1.5m diameter high gain antenna; ② 900 Watt Solar panels, two groups of 1800 watts; ③ star sensor; ④ 8 groups of 5N thrust attitude control thrusters; ⑤ exi multispectral camera; ⑥ EMUs ultraviolet spectrometer; ⑦ emirs infrared spectrometer; and (8) six groups of 120N thrust main thrusters. < / P > < p > hope’s multispectral camera is called Emirates exploration imager, the emirate exploration camera. It has six groups of discrete band-pass filters controlled by mechanical structure to filter different spectra. Simply put, it is possible to change the sensitive spectral region by mechanically switching the “lens”. The six groups of filters include three groups of visible and three groups of ultraviolet filters. The combination of the three colors in the visible light band can display the real color picture that the human eye can directly watch. Ultraviolet light can supplement the details we can’t see. The camera will photograph and measure water, ice, dust, aerosols, ozone hole, etc. < / P > < p > the exi module was developed by the atmospheric and Space Physics Laboratory of the University of Colorado at Boulder in the United States of America and the Muhammad bin Rashid Space Center in the United Arab Emirates. The mbrsc is named after the vice president of the United Arab Emirates as mentioned earlier. < / P > < p > UV light has high frequency and short wavelength, so it has poor penetration but good directivity. For hope flying in space, EMUs will be used to analyze the characteristics of Mars’ upper atmosphere, especially the thermal layer, hydrogen and oxygen atoms. Their global characteristics and regional variations were studied in the emission spectrum wavelength range of 100nm-170nm. In other words, EMUs will focus on the escape of hydrogen and oxygen atoms, the characteristics and physical processes of the upper atmosphere. This paper attempts to interpret the physical mechanism of Martian atmospheric escape and build a model of Martian water environment change. < p > < p > Emirates Mars infrared spectrometer is still a straightforward name. It seems that scientists in the United Arab Emirates are far less capable of naming than American scientists – American scientists can always come up with some bizarre names that are mechanically copied. In contrast, infrared light has the opposite characteristics with ultraviolet light. It has a long wavelength, so it has good penetrability, but low energy and poor directivity. The main mission of emirs, different from EMUs, is to provide a view of the middle and lower atmosphere of Mars. Note: engineers are mapping hope. Inside the red circle is the emirs protected by the dust cover. You can also see it in the first two pictures. Infrared is a physical entity that we are very familiar with. We know that infrared ray is closely related to temperature. All kinds of objects above absolute zero always radiate infrared rays. The radiation characteristics depend on temperature. The primary task of the infrared spectrometer is to measure the temperature characteristics of the middle and lower atmosphere by observing the infrared radiation from Mars. When the temperature is extended, the refraction / reflection characteristics of different media are different, so water ice, water vapor, dust, aerosol and other media can also be analyzed by emirs. < p > < p > emirs was developed by Arizona State University with the support of mbrsc. < p > < p > it can be seen that this series of three sets of scientific payload is mainly to study the atmosphere of Mars, including climate and meteorological events. So the name “meteorological satellite” is indeed worthy of its name. The total emission mass of hope detector is 1350kg, dry weight is 550Kg, width is 2.37M, length is 2.9m. Generally speaking, it is similar to a car, and its emission mass is the smallest among the three sets of detectors in the same period. The main antenna is a set of 1.5m diameter high gain antenna, which must face the earth when communicating. The other antennas it carries are not powerful enough to communicate directly with the earth. < / P > < p > as we mentioned before, the appearance and structural design of hope are quite different from the concept drawings. In the concept diagram, there is a hexagonal prism, and three groups of solar panels are installed symmetrically, each with a rated power of 600 watts. But in the actual design, the main structure has become a four prism, that is, a cuboid. It is also obviously impossible to install three groups of solar panels symmetrically, instead of two groups of 900 watts each. The attitude adjustment task of hope is mainly controlled by a set of 8 RCS nozzles, and the thrust of each nozzle is 5 n. This nozzle is very common in spaceships and satellites. The nozzles on our Shenzhou spacecraft that point to all directions and intermittently eject air are RCS. In addition, hope also carries a momentum wheel to control the attitude of the spacecraft based on the principle of conservation of angular momentum, so that its high gain antenna can always point to the earth. < / P > < p > hope’s attitude determination task is completed by the star sensor. The star sensor is actually a group of at least two cameras with a very narrow field of view. The star sensor observes the sky, looks for a specific constellation, and then compares it with the position of the sun to get the attitude information of the current detector. If the attitude is abnormal, let the RCS and momentum wheel mentioned above be adjusted. < / P > < p >} note: the two convex pyramids on the hope are the shield of the star sensor, and the narrow field camera, the body of the star sensor, will be installed at its root. In addition, this photo is taken in the direction of many scientific payloads. It can be seen that the scientific payload has not been installed and the data cable is exposed. After launching, the maneuver and deceleration of hope will be completed by six groups of main engines with 120 n thrust respectively. The more the main engines, the better. This is also mentioned in China’s Chang’e plan. There are usually two reasons why multiple engines are used. The first is a single engine