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Tiandu-1
Tiandu satellites are a pair of Chinese Lunar Exploration Program's lunar navigation and communications test satellites based on Queqiao-2 relay satellite technology. Design and development Tiandu satellites will perform navigation and communications technology verification experiments while flying in formation in lunar orbit. Satellite-to-ground laser ranging as well as intersatellite microwave ranging techniques will also be tested. The Tiandu satellites' mission is to inform the design of China's proposed Queqiao lunar navigation and communication array. Supporting services for lunar surface operations would be provided by such system. Line-of-sight communications limits affect uncrewed and crewed operations on the Moon, especially at the lunar south pole, an area of great interest, or the lunar far side. The Tiandu-1 carries a Ka dual-band integrated communication payload, a laser retroreflector, a space router and other payloads. The Tiandu-2 carries a communicati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Long March 8
Long March 8 () is an orbital launch vehicle developed by the China Academy of Launch Vehicle Technology to launch up to 5000 kg to a 700 km altitude Sun-synchronous orbit (SSO). The rocket is based on the Long March 7 with its first stage and two boosters, along with the existing liquid hydrogen burning third stage of the Long March 3A/ 3B/ 3C and 7A as its second stage. The boosters are omitted in the "core only" variant that first flew on its second launch in February 2022. A planned future launch vehicle variant of the Long March 8 will be partially reusable by featuring a combined booster recovery of the first stage and the boosters as a single unit. The maiden flight of the Long March 8 was launched on 22 December 2020 from the Wenchang Spacecraft Launch Site. CZ-8A variant An upgraded version of the Long March 8, the Long March 8A (), has successfully debuted on February 11, 2025 with increased capability of up to 7 tonnes to a 700 km altitude sun-synchr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Queqiao-2 Relay Satellite
''Queqiao-2'' relay satellite (), is the second of the communications relay and radio astronomy satellites designed to support the fourth phase the Chinese Lunar Exploration Program, after Queqiao-1 launched in 2018. The China National Space Administration (CNSA) launched the Queqiao-2 relay satellite on 20 March 2024 to an elliptical frozen orbit around the Moon to support communications from the far side of the Moon and the Lunar south pole. The name ''Queqiao'' (, "Magpie Bridge") was inspired by and came from the Chinese tale ''The Cowherd and the Weaver Girl''. Background and mission planning The initial phase of the International Lunar Research Station (ILRS), consisting of the Chang'e 7 and Chang'e 8 probes, was scheduled to be built in 2026 and 2028 on the southern edge of the South Pole–Aitken basin located on the far side of the Moon. While the Queqiao so far only had to connect with two probes on the far side of the Moon (Chang'e 4 lander and ''Yutu-2'' rover), fu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nanjing University
Nanjing University (NJU) is a public university in Nanjing, Jiangsu, China. It is affiliated and sponsored by the Ministry of Education. The university is part of Project 211, Project 985, and the Double First-Class Construction. The university is a member of the C9 League. Established in 1902 as Sanjiang Normal School, Nanjing University underwent a number of name changes, such as Nanjing Higher Normal School, National Southeastern University and National Central University, until it was renamed Nanjing University in 1950. It merged with the University of Nanking in 1952. Nanjing University has four campuses: the Xianlin campus in the northeast of Nanjing, the Gulou campus in the city center of Nanjing, the Pukou campus in the Pukou District of Nanjing, and the Suzhou campus in the city of Suzhou. Faculties Its faculty, including part-time faculty, includes more than twenty Nobel Laureates engaged in teaching. The university is a Double First-Class Construction u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Line Of Sight
The line of sight, also known as visual axis or sightline (also sight line), is an imaginary line between a viewer/ observer/ spectator's eye(s) and a subject of interest, or their relative direction. The subject may be any definable object taken note of or to be taken note of by the observer, at any distance more than least distance of distinct vision. In optics, refraction of a ray due to use of lenses can cause distortion. Shadows, patterns and movement can also influence line of sight interpretation (as in optical illusions). The term "line" typically presumes that the light by which the observed object is seen travels as a straight ray, which is sometimes not the case as light can take a curved/angulated path when reflected from a mirror, refracted by a lens or density changes in the traversed media, or deflected by a gravitational field. Fields of study feature specific targets, such as vessels in navigation, marker flags or natural features in surveying, celestial objec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spacecraft Launched By Long March Rockets
A spacecraft is a vehicle that is designed to fly and operate in outer space. Spacecraft are used for a variety of purposes, including communications, Earth observation, meteorology, navigation, space colonization, planetary exploration, and transportation of humans and cargo. All spacecraft except single-stage-to-orbit vehicles cannot get into space on their own, and require a launch vehicle (carrier rocket). On a sub-orbital spaceflight, a space vehicle enters space and then returns to the surface without having gained sufficient energy or velocity to make a full Earth orbit. For orbital spaceflights, spacecraft enter closed orbits around the Earth or around other celestial bodies. Spacecraft used for human spaceflight carry people on board as crew or passengers from start or on orbit (space stations) only, whereas those used for robotic space missions operate either autonomously or telerobotically. Robotic spacecraft used to support scientific research are space ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chinese Space Probes
Chinese may refer to: * Something related to China * Chinese people, people identified with China, through nationality, citizenship, and/or ethnicity **Han Chinese, East Asian ethnic group native to China. **''Zhonghua minzu'', the supra-ethnic concept of the Chinese nation ** List of ethnic groups in China, people of various ethnicities in contemporary China ** Ethnic minorities in China, people of non-Han Chinese ethnicities in modern China ** Ethnic groups in Chinese history, people of various ethnicities in historical China ** Nationals of the People's Republic of China ** Nationals of the Republic of China ** Overseas Chinese, Chinese people residing outside the territories of mainland China, Hong Kong, Macau, and Taiwan * Sinitic languages, the major branch of the Sino-Tibetan language family ** Chinese language, a group of related languages spoken predominantly in China, sharing a written script (Chinese characters in traditional and simplified forms) *** Standard Chines ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2024 In China
Events in the year 2024 in China. Incumbents * General Secretary of the Chinese Communist Party (paramount leader) – Xi Jinping * President – Xi Jinping * Premier - Li Qiang * Congress chairman – Zhao Leji * Consultative Conference chairman – Wang Huning * Vice President - Han Zheng * Supervision Commission director – Liu Jinguo Events January * 12 January – 2024 Pingdingshan mining explosion: Ten people are killed and six others are missing after an explosion at a coal mine in Pingdingshan, Henan. * 20 January – Yingcai Boarding School fire: Thirteen third grade children are killed and another is injured in a boarding school dormitory fire in Dushu, Henan Province. The school's director is arrested. * 22 January – A landslide in Zhaotong, Yunnan, kills 44 people. * 23 January – 2024 Uqturpan earthquake: A magnitude 7.1 earthquake strikes Uqturpan County in Xinjiang Province, killing three people, all in Xinjiang, and injuring at least 50 people, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microwave
Microwave is a form of electromagnetic radiation with wavelengths shorter than other radio waves but longer than infrared waves. Its wavelength ranges from about one meter to one millimeter, corresponding to frequency, frequencies between 300 MHz and 300 GHz, broadly construed. A more common definition in radio-frequency engineering is the range between 1 and 100 GHz (wavelengths between 30 cm and 3 mm), or between 1 and 3000 GHz (30 cm and 0.1 mm). In all cases, microwaves include the entire super high frequency, super high frequency (SHF) band (3 to 30 GHz, or 10 to 1 cm) at minimum. The boundaries between far infrared, terahertz radiation, microwaves, and ultra-high-frequency (UHF) are fairly arbitrary and differ between different fields of study. The prefix ' in ''microwave'' indicates that microwaves are small (having shorter wavelengths), compared to the radio waves used in prior radio technology. Frequencies in the micr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elliptic Orbit
In astrodynamics or celestial mechanics, an elliptical orbit or eccentric orbit is an orbit with an eccentricity of less than 1; this includes the special case of a circular orbit, with eccentricity equal to 0. Some orbits have been referred to as "elongated orbits" if the eccentricity is "high" but that is not an explanatory term. For the simple two body problem, all orbits are ellipses. In a gravitational two-body problem, both bodies follow similar elliptical orbits with the same orbital period around their common barycenter. The relative position of one body with respect to the other also follows an elliptic orbit. Examples of elliptic orbits include Hohmann transfer orbits, Molniya orbits, and tundra orbits. Velocity Under standard assumptions, no other forces acting except two spherically symmetrical bodies (m_1) and (m_2), the orbital speed (v\,) of one body traveling along an elliptical orbit can be computed from the vis-viva equation as: :v = \sqrt where: * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Universal Time Coordinated
Coordinated Universal Time (UTC) is the primary time standard globally used to regulate clocks and time. It establishes a reference for the current time, forming the basis for civil time and time zones. UTC facilitates international communication, navigation, scientific research, and commerce. UTC has been widely embraced by most countries and is the effective successor to Greenwich Mean Time (GMT) in everyday usage and common applications. In specialised domains such as scientific research, navigation, and timekeeping, other standards such as UT1 and International Atomic Time (TAI) are also used alongside UTC. UTC is based on TAI (International Atomic Time, abbreviated from its French name, ''temps atomique international''), which is a weighted average of hundreds of atomic clocks worldwide. UTC is within about one second of mean solar time at 0° longitude, the currently used prime meridian, and is not adjusted for daylight saving time. The coordination of time and freque ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dual-band
In telecommunications, a multi-band device (including (2) dual-band, (3) tri-band, (4) quad-band and (5) penta-band devices) is a communication device (especially a mobile phone) that supports multiple radio frequency bands. All devices which have more than one channel use multiple frequencies; a band however is a group of frequencies containing many channels. Multiple bands in mobile devices support roaming between different regions where different standards are used for mobile telephone services. Where the bands are widely separated in frequency, parallel transmit and receive signal path circuits must be provided, which increases the cost, complexity and power demand of multi-band devices. The term quad-band describes a device that supports four frequency bands: the 850 and 1900 MHz bands, which are used in the Americas, and 900 / 1800, which are used in most other parts of the world. Most GSM/UMTS phones support all four bands, while most CDMA2000/1xRTT phones (mostly North Am ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ka Band
The Ka band (pronounced as either "kay-ay band" or "ka band") is a portion of the microwave part of the electromagnetic spectrum. The designation "Ka-band" is from Kurz-above, which stems from the German word ''kurz,'' meaning "short". There is no standard definition of Ka-band. IEEE Standard letter designations for Radar Bands define the nominal frequency range for Ka band in the range 27–40 gigahertz (GHz) in Tables 1 and 2 of IEEE Standard 521 i.e. wavelengths from slightly over one centimeter down to 7.5 millimeters. The ITU however approves Ka-band satellite networks in the 17.3-31 GHz frequency range, with most Ka-band satellite networks having uplinks in the 27.5–31 GHz and downlinks in the 17.7–21.2 GHz range. The band is called Ka, short for "K-above" because it is the upper part of the original (now obsolete) NATO K band, which was split into three bands because of the presence of the atmospheric water vapor resonance peak at 22.24 G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
