Chang'e 1 (; ) was an

uncrewed An uncrewed vehicle or unmanned vehicle is a vehicle without a person on board. Uncrewed vehicles can either be under telerobotic control—remote controlled or remote guided vehicles—or they can be autonomously controlled—autonomous vehicl ...

Chinese

lunar Lunar most commonly means "of or relating to the Moon". Lunar may also refer to: Arts and entertainment * ''Lunar'' (series), a series of video games * "Lunar" (song), by David Guetta * "Lunar", a song by Priestess from the 2009 album ''Prior t ...

-orbiting

spacecraft A spacecraft is a vehicle that is designed spaceflight, to fly and operate in outer space. Spacecraft are used for a variety of purposes, including Telecommunications, communications, Earth observation satellite, Earth observation, Weather s ...

, part of the first phase of the

Chinese Lunar Exploration Program The Chinese Lunar Exploration Program (CLEP; ), also known as the Chang'e Project () after the Chinese Moon goddess Chang'e, is an ongoing series of robotic Moon missions by the China National Space Administration (CNSA). Engineering Program ...

. The spacecraft was named after the Chinese Moon goddess,

Chang'e Chang'e ( ; ), originally known as Heng'e (), is the goddess of the Moon and wife of Hou Yi, the great archer. Renowned for her beauty, Chang'e is also known for her ascending to the Moon with her pet Yu Tu, the Moon Rabbit and living in the Mo ...

. Chang'e 1 was launched on 24 October 2007 at 10:05:04

UTC 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 communica ...

from

Xichang Satellite Launch Center The Xichang Satellite Launch Center (XSLC), also known as the Xichang Space Center, is a spaceport in China. It is located in (), Mianning county, approximately northwest of Xichang, Liangshan Yi Autonomous Prefecture in Sichuan. It is op ...

. It left lunar transfer orbit on 31 October and entered

lunar orbit In astronomy and spaceflight, a lunar orbit (also known as a selenocentric orbit) is an orbit by an object around Earth's Moon. In general these orbits are not circular. When farthest from the Moon (at apoapsis) a spacecraft is said to be at apo ...

on 5 November. The first picture of the Moon was relayed on 26 November 2007. On 12 November 2008, a map of the entire lunar surface was released, produced from data collected by Chang'e 1 between November 2007 and July 2008. The mission was scheduled to continue for a year, but was later extended and the spacecraft operated until 1 March 2009, when it was taken out of orbit. It impacted the surface of the Moon at 08:13 UTC. Data gathered by Chang'e 1 was used to create an accurate and high resolution 3-D map of the lunar surface."China's map leaps over the moon"
''Asia Times'' Chang'e 1 was the first lunar probe to conduct passive, multi-channel, microwave remote sensing of the Moon by using a microwave radiometer. Its sister orbital probe

Chang'e 2 Chang'e 2 (; ) is a Chinese uncrewed lunar probe that was launched on 1 October 2010. It was a follow-up to the Chang'e 1 lunar probe, which was launched in 2007. Chang'e 2 was part of the first phase of the Chinese Lunar Exploration Program, ...

was launched on 1 October 2010.

Overview

The

is designed to be conducted in four Chang'e 4 press conference
CNSA, broadcast on 14 January 2019. phases of incremental technological advancement: The first is simply reaching lunar orbit, a task completed by Chang'e 1 in 2007 and

in 2010. The second is landing and roving on the Moon, as

Chang'e 3 Chang'e 3 (; ) is a robotic lunar exploration mission operated by the China National Space Administration (CNSA), incorporating a robotic lander and China's first lunar rover. It was launched in December 2013 as part of the second phase of ...

did in 2013 and

Chang'e 4 Chang'e 4 (; ) is a robotic spacecraft mission in the Chinese Lunar Exploration Program of the CNSA. It made a soft landing on the far side of the Moon, the first spacecraft to do so, on 3 January 2019. A communication relay satellite, , w ...

did in 2019. The third is collecting lunar samples from the near-side and sending them to Earth, a task for the

Chang'e 5 Chang'e 5 () was the fifth lunar exploration mission in the Chinese Lunar Exploration Program of CNSA, and China's first lunar sample-return mission. Like its predecessors, the spacecraft is named after the Chinese moon goddess, Chang'e. ...

and

Chang'e 6 Chang'e 6 () was the sixth robotic lunar exploration mission by the China National Space Administration (CNSA) and the second CNSA lunar sample-return mission. Like its predecessors in the Chinese Lunar Exploration Program, the spacecraft is ...

missions. The fourth phase consists of development of a robotic research station near the Moon's south pole.China's Planning for Deep Space Exploration and Lunar Exploration before 2030
(PDF) XU Lin, ZOU Yongliao, JIA Yingzhuo. ''Space Sci''., 2018, 38(5): 591-592. The program aims to facilitate a crewed lunar landing in the 2030s and to possibly build an outpost near the south pole.

Objectives

The Chang'e 1 mission had four major goals: # Obtaining three-dimensional images of the landforms and geological structures of the

lunar surface The geology of the Moon (sometimes called selenology, although the latter term can refer more generally to "lunar science") is the structure and composition of the Moon, which is quite different from that of Earth. The Moon lacks a true atmosphe ...

, so as to provide a reference for planned future soft landings. The orbit of Chang'e 1 around the Moon was designed to provide complete coverage, including areas near the north and south poles not covered by previous missions. # Analysing and mapping the abundance and distribution of various chemical elements on the lunar surface as part of an evaluation of potentially useful resources on the Moon. China hopes to extend the number of elements studied to 14 (

potassium Potassium is a chemical element; it has Symbol (chemistry), symbol K (from Neo-Latin ) and atomic number19. It is a silvery white metal that is soft enough to easily cut with a knife. Potassium metal reacts rapidly with atmospheric oxygen to ...

(K),

thorium Thorium is a chemical element; it has symbol Th and atomic number 90. Thorium is a weakly radioactive light silver metal which tarnishes olive grey when it is exposed to air, forming thorium dioxide; it is moderately soft, malleable, and ha ...

(Th),

uranium Uranium is a chemical element; it has chemical symbol, symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Ura ...

(U),

oxygen Oxygen is a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), non ...

(O),

silicon Silicon is a chemical element; it has symbol Si and atomic number 14. It is a hard, brittle crystalline solid with a blue-grey metallic lustre, and is a tetravalent metalloid (sometimes considered a non-metal) and semiconductor. It is a membe ...

(Si),

magnesium Magnesium is a chemical element; it has Symbol (chemistry), symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 ...

(Mg),

aluminium Aluminium (or aluminum in North American English) is a chemical element; it has chemical symbol, symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium has ...

(Al),

calcium Calcium is a chemical element; it has symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to it ...

(Ca),

tellurium Tellurium is a chemical element; it has symbol Te and atomic number 52. It is a brittle, mildly toxic, rare, silver-white metalloid. Tellurium is chemically related to selenium and sulfur, all three of which are chalcogens. It is occasionally fou ...

(Te),

titanium Titanium is a chemical element; it has symbol Ti and atomic number 22. Found in nature only as an oxide, it can be reduced to produce a lustrous transition metal with a silver color, low density, and high strength, resistant to corrosion in ...

(Ti),

sodium Sodium is a chemical element; it has Symbol (chemistry), symbol Na (from Neo-Latin ) and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 element, group 1 of the peri ...

(Na),

manganese Manganese is a chemical element; it has Symbol (chemistry), symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese was first isolated in the 1770s. It is a transition m ...

(Mn),

chromium Chromium is a chemical element; it has Symbol (chemistry), symbol Cr and atomic number 24. It is the first element in Group 6 element, group 6. It is a steely-grey, Luster (mineralogy), lustrous, hard, and brittle transition metal. Chromium ...

(Cr), and

lanthanum Lanthanum is a chemical element; it has symbol La and atomic number 57. It is a soft, ductile, silvery-white metal that tarnishes slowly when exposed to air. It is the eponym of the lanthanide series, a group of 15 similar elements bet ...

(La)), compared with the 10 elements (K, U, Th, Fe (

iron Iron is a chemical element; it has symbol Fe () and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, forming much of Earth's o ...

), Ti, O, Si, Al, Mg, and Ca) previously probed by

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...

Lunar Prospector ''Lunar Prospector'' was a spacecraft that orbited the Moon for 19 months in 1998-99. From a low polar orbit, it mapped surface composition including lunar hydrogen deposits, measured magnetic and gravity fields, and studied lunar outgassing e ...

. # Probing the features of the lunar soil and assessing its depth, as well as the amount of

helium-3 Helium-3 (3He see also helion) is a light, stable isotope of helium with two protons and one neutron. (In contrast, the most common isotope, helium-4, has two protons and two neutrons.) Helium-3 and hydrogen-1 are the only stable nuclides with ...

(³He) present. # Probing the space environment between 40,000 km. (24854.8 mi) and 400,000 km (248548.5 mi) from the Earth, recording data on the solar wind and studying the impact of solar activity on the Earth and the Moon. In addition, the lunar probe engineering system, composed of five major systems – the satellite system, the launch vehicle system, the launch site system, the monitoring and control system and the ground application system – accomplished five goals: * Researching, developing and launching China's first lunar probe * Mastering the basic technology of placing satellites in lunar orbit * Conducting China's first scientific exploration of the Moon * Initially forming a lunar probe space engineering system * Accumulating experience for the later phases of China's lunar exploration program

Mission

According to the schedule, detailed design of the first program milestone was completed by September 2004. Research and development of a prototype probe and relevant testing of the probe were finished before the end of 2005. Design, manufacture, general assembly, test and ground experiments of the lunar orbiter were finished before December 2006. Originally scheduled for April 2007, the launch was postponed until October as this was "a better time for sending a satellite into the Moon's orbit". Chang'e 1 was launched by a

Long March 3A The Long March 3A (), also known as the Chang Zheng 3A, CZ-3A and LM-3A, is a Chinese orbital carrier rocket design. It is a 3-stage rocket, and is usually used to place communications satellites and Beidou navigation satellites into geosynch ...

rocket at 10:05 GMT on October 24, 2007, from

Sichuan Sichuan is a province in Southwestern China, occupying the Sichuan Basin and Tibetan Plateau—between the Jinsha River to the west, the Daba Mountains to the north, and the Yunnan–Guizhou Plateau to the south. Its capital city is Cheng ...

Province. After liftoff, Chang'e 1 made three orbits around the Earth, a burn at

perigee An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. The line of apsides (also called apse line, or major axis of the orbit) is the line connecting the two extreme values. Apsides perta ...

extending the orbit's

apogee An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. The line of apsides (also called apse line, or major axis of the orbit) is the line connecting the two extreme values. Apsides perta ...

further each time, until a final translunar injection burn placed it on course for the Moon on October 31, 2007. Another burn placed it in a

polar orbit A polar orbit is one in which a satellite passes above or nearly above both poles of the body being orbited (usually a planet such as the Earth, but possibly another body such as the Moon or Sun) on each revolution. It has an inclination of abo ...

around the Moon, with burns at the periselenium of the first three orbits decreasing the aposelenium until it entered a final circular orbit. Lunar orbit insertion was achieved on the November 5, 2007. To mark this occasion, the probe transmitted 30 classical Chinese songs and musical pieces, including "My Motherland", "The Song of the Yangtze River", and "High Mountains and Flowing Water". The probe was remotely controlled from stations at

Qingdao Qingdao, Mandarin: , (Qingdao Mandarin: t͡ɕʰiŋ˧˩ tɒ˥) is a prefecture-level city in the eastern Shandong Province of China. Located on China's Yellow Sea coast, Qingdao was long an important fortress. In 1897, the city was ceded to G ...

and

Kashgar Kashgar () or Kashi ( zh, c=喀什) is a city in the Tarim Basin region of southern Xinjiang, China. It is one of the westernmost cities of China, located near the country's border with Kyrgyzstan and Tajikistan. For over 2,000 years, Kashgar ...

, as the first use of the

Chinese Deep Space Network The Chinese Deep Space Network (CDSN) is a network of large antennas and communication facilities that are used for radio astronomy, radar observations, and spacecraft missions of China. The CDSN is managed by the China Satellite Launch and Trac ...

. The

ESA The European Space Agency (ESA) is a 23-member international organization devoted to space exploration. With its headquarters in Paris and a staff of around 2,547 people globally as of 2023, ESA was founded in 1975 in the context of European ...

Maspalomas Tracking Station was also used to transmit signals to and from the probe. The first pictures of the Moon were relayed on November 26, 2007. The probe was designed to orbit the Moon for one year, but operations were later extended, and it remained in lunar orbit until March 1, 2009.

End of mission

On 1 March 2009, at 08:13:10 UTC, Chang'e 1 crashed onto the surface of the Moon, ending its mission. According to the State Administration of Science, Technology and Industry for National Defense (China), this was a planned and controlled impact. Impact point was . During its orbital mission the probe transmitted 1,400 gigabits or 175 gigabytes (GB) of data.

Design and instrumentation

The Chang'e 1 spacecraft had a mass of , with a payload, carrying 24 instruments including a

charge-coupled device A charge-coupled device (CCD) is an integrated circuit containing an array of linked, or coupled, capacitors. Under the control of an external circuit, each capacitor can transfer its electric charge to a neighboring capacitor. CCD sensors are a ...

(CCD)

stereo camera A stereo camera is a type of camera with two or more lenses with a separate image sensor or film frame for each lens. This allows the camera to simulate human binocular vision, and therefore gives it the ability to capture three-dimensional ...

, microprobe instruments, and a high-energy solar particle detector. * Stereo camera with an

optical resolution Optical resolution describes the ability of an imaging system to resolve detail, in the object that is being imaged. An imaging system may have many individual components, including one or more lenses, and/or recording and display components. E ...

of and

spectrometer A spectrometer () is a scientific instrument used to separate and measure Spectrum, spectral components of a physical phenomenon. Spectrometer is a broad term often used to describe instruments that measure a continuous variable of a phenomeno ...

imager operating at

wavelength In physics and mathematics, wavelength or spatial period of a wave or periodic function is the distance over which the wave's shape repeats. In other words, it is the distance between consecutive corresponding points of the same ''phase (waves ...

s of * Laser

altimeter An altimeter or an altitude meter is an instrument used to measure the altitude of an object above a fixed level. The measurement of altitude is called altimetry, which is related to the term bathymetry, the measurement of depth under water. Ty ...

with , laser, a range resolution of and a spot size of * Imaging spectrometer * Gamma and X-ray spectrometer working in an energy range of 0.5 to 50

keV In physics, an electronvolt (symbol eV), also written electron-volt and electron volt, is the measure of an amount of kinetic energy gained by a single electron accelerating through an electric potential difference of one volt in vacuum. When us ...

for

X-rays An X-ray (also known in many languages as Röntgen radiation) is a form of high-energy electromagnetic radiation with a wavelength shorter than those of ultraviolet rays and longer than those of gamma rays. Roughly, X-rays have a wavelength ran ...

and 300 keV to 9 MeV for

gamma ray A gamma ray, also known as gamma radiation (symbol ), is a penetrating form of electromagnetic radiation arising from high energy interactions like the radioactive decay of atomic nuclei or astronomical events like solar flares. It consists o ...

s *

Microwave radiometer A microwave radiometer (MWR) is a radiometer that measures energy emitted at one millimeter-to-metre wavelengths (frequencies of 0.3–300 GHz) known as microwaves. Microwave radiometers are very sensitive receivers designed to measure thermally ...

detecting 3, 7.8, 19.35 and 37

GHz The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), often described as being equivalent to one event (or Cycle per second, cycle) per second. The hertz is an SI derived unit whose formal expression in ter ...

with a maximal penetration depth of 30, 20, 10, 1 m (98.4, 65.6, 32.8, 3.3 ft) and a

thermal A thermal column (or thermal) is a rising mass of buoyant air, a convective current in the atmosphere, that transfers heat energy vertically. Thermals are created by the uneven heating of Earth's surface from solar radiation, and are an example ...

resolution of 0.5 K * High energy particle detector and two

solar wind The solar wind is a stream of charged particles released from the Sun's outermost atmospheric layer, the Stellar corona, corona. This Plasma (physics), plasma mostly consists of electrons, protons and alpha particles with kinetic energy betwee ...

detectors capable of the detection of

electron The electron (, or in nuclear reactions) is a subatomic particle with a negative one elementary charge, elementary electric charge. It is a fundamental particle that comprises the ordinary matter that makes up the universe, along with up qua ...

s and heavy

ion An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convent ...

s up to 730 MeV

Achievements

* Chang'e 1 created an accurate and high resolution 3-D map ever of the lunar surface. * Chang'e 1 conducted world's first passive, multi-channel, microwave remote sensing of the Moon.

References

External links

CLEP Official site

Chang'e 1 Mission Profile
b
NASA's Solar System Exploration

{{Orbital launches in 2007 Chinese Lunar Exploration Program Missions to the Moon Chinese space probes Space probes launched in 2007 2007 in China Spacecraft that impacted the Moon 2009 on the Moon Spacecraft launched by Long March rockets