Chang'e program
Encyclopedia
Chang’e 1 was an unmanned
Chinese lunar
-orbiting spacecraft
, part of the first phase of the Chinese Lunar Exploration Program
. The spacecraft was named after the Chinese Moon goddess, Chang'e
.
Chang'e 1 was launched on 24 October 2007 at 10:05:04 UTC
from Xichang Satellite Launch Center
. It left lunar transfer orbit on 31 October and entered lunar orbit
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 able to create the most accurate and highest resolution 3-D map ever created of the lunar surface.
Its sister orbital probe Chang'e 2
was launched on the first of October 2010.
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:
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
rocket at 10:05 GMT on October 24, 2007 from Xichang Satellite Launch Center
in Sichuan
Province.
After liftoff, Chang'e 1 made three orbits around the Earth, a burn at perigee
extending the orbit's apogee
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
around the Moon, with burns at the perilune of the first three orbits decreasing the apolune 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
and Kashgar
, as the first use of the Chinese Deep Space Network
. The ESA 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.
, 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 1.50°S 52.36°E. During its orbital mission the probe transmitted 1,400 gigabits or 175 gigabytes (GB) of data.
(CCD) stereo camera
, microprobe instruments, and a high-energy solar particle detector.
Robotic spacecraft
A robotic spacecraft is a spacecraft with no humans on board, that is usually under telerobotic control. A robotic spacecraft designed to make scientific research measurements is often called a space probe. Many space missions are more suited to telerobotic rather than crewed operation, due to...
Chinese lunar
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
-orbiting spacecraft
Spacecraft
A spacecraft or spaceship is a craft or machine designed for spaceflight. Spacecraft are used for a variety of purposes, including communications, earth observation, meteorology, navigation, planetary exploration and transportation of humans and cargo....
, part of the first phase of the Chinese Lunar Exploration Program
Chinese Lunar Exploration Program
Chinese Lunar Exploration Program , also known as the Chang'e program, is a program of robotic and human missions to the Moon undertaken by the China National Space Administration , the space agency of the People's Republic of China...
. The spacecraft was named after the Chinese Moon goddess, Chang'e
Chang'e
Chang'e may refer to:* Chang'e - a traditional Chinese lunar goddess* The Chinese Chang'e space program, part of the Chinese Lunar Exploration Program :** Chang'e 1 - the first CLEP lunar orbiter, launched on 24 October 2007...
.
Chang'e 1 was launched on 24 October 2007 at 10:05:04 UTC
Coordinated Universal Time
Coordinated Universal Time is the primary time standard by which the world regulates clocks and time. It is one of several closely related successors to Greenwich Mean Time. Computer servers, online services and other entities that rely on having a universally accepted time use UTC for that purpose...
from Xichang Satellite Launch Center
Xichang Satellite Launch Center
The Xichang Satellite Launch Center also known as Base 27 , is a People’s Republic of China space vehicle launch facility approximately 64 km northwest of Xichang City, Liangshan Yi Autonomous Prefecture in Sichuan Province....
. It left lunar transfer orbit on 31 October and entered lunar orbit
Lunar orbit
In astronomy, lunar orbit refers to the orbit of an object around the Moon.As used in the space program, this refers not to the orbit of the Moon about the Earth, but to orbits by various manned or unmanned spacecraft around the Moon...
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 able to create the most accurate and highest resolution 3-D map ever created of the lunar surface.
Its sister orbital probe Chang'e 2
Chang'e 2
Chang'e 2 is a Chinese unmanned 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, and conducted research from a 100-kilometer-high lunar orbit...
was launched on the first of October 2010.
Objectives
The Chang'e 1 mission had four major goals:- Obtaining three-dimensional images of the landforms and geological structures of the lunar surface, 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 (potassiumPotassiumPotassium is the chemical element with the symbol K and atomic number 19. Elemental potassium is a soft silvery-white alkali metal that oxidizes rapidly in air and is very reactive with water, generating sufficient heat to ignite the hydrogen emitted in the reaction.Potassium and sodium are...
(K), thoriumThoriumThorium is a natural radioactive chemical element with the symbol Th and atomic number 90. It was discovered in 1828 and named after Thor, the Norse god of thunder....
(Th), uraniumUraniumUranium is a silvery-white metallic chemical element in the actinide series of the periodic table, with atomic number 92. It is assigned the chemical symbol U. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons...
(U), oxygenOxygenOxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
(O), siliconSiliconSilicon is a chemical element with the symbol Si and atomic number 14. A tetravalent metalloid, it is less reactive than its chemical analog carbon, the nonmetal directly above it in the periodic table, but more reactive than germanium, the metalloid directly below it in the table...
(Si), magnesiumMagnesiumMagnesium is a chemical element with the symbol Mg, atomic number 12, and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the Earth's crust and ninth in the known universe as a whole...
(Mg), aluminiumAluminiumAluminium or aluminum is a silvery white member of the boron group of chemical elements. It has the symbol Al, and its atomic number is 13. It is not soluble in water under normal circumstances....
(Al), calciumCalciumCalcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...
(Ca), tellurium (Te), titaniumTitaniumTitanium is a chemical element with the symbol Ti and atomic number 22. It has a low density and is a strong, lustrous, corrosion-resistant transition metal with a silver color....
(Ti), sodiumSodiumSodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the alkali metals; its only stable isotope is 23Na. It is an abundant element that exists in numerous minerals, most commonly as sodium chloride...
(Na), manganeseManganeseManganese is a chemical element, designated by the symbol Mn. It has the atomic number 25. It is found as a free element in nature , and in many minerals...
(Mn), chromiumChromiumChromium is a chemical element which has the symbol Cr and atomic number 24. It is the first element in Group 6. It is a steely-gray, lustrous, hard metal that takes a high polish and has a high melting point. It is also odorless, tasteless, and malleable...
(Cr), and lanthanumLanthanumLanthanum is a chemical element with the symbol La and atomic number 57.Lanthanum is a silvery white metallic element that belongs to group 3 of the periodic table and is the first element of the lanthanide series. It is found in some rare-earth minerals, usually in combination with cerium and...
(La)), compared with the 10 elements (K, U, Th, Fe (ironIronIron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...
), Ti, O, Si, Al, Mg, and Ca) previously probed by NASANASAThe National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
's Lunar ProspectorLunar ProspectorThe Lunar Prospector mission was the third selected by NASA for full development and construction as part of the Discovery Program. At a cost of $62.8 million, the 19-month mission was designed for a low polar orbit investigation of the Moon, including mapping of surface composition and possible...
. - Probing the features of the lunar soil and assessing its depth, as well as the amount of helium-3Helium-3Helium-3 is a light, non-radioactive isotope of helium with two protons and one neutron. It is rare on Earth, and is sought for use in nuclear fusion research...
(³He) present. - Probing the space environment between 40,000 km and 400,000 km 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
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
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. It is a 3-stage rocket, and is usually used to place communications satellites and Beidou navigation satellites into geosynchronous transfer orbits.It has formed the basis of the Long March...
rocket at 10:05 GMT on October 24, 2007 from Xichang Satellite Launch Center
Xichang Satellite Launch Center
The Xichang Satellite Launch Center also known as Base 27 , is a People’s Republic of China space vehicle launch facility approximately 64 km northwest of Xichang City, Liangshan Yi Autonomous Prefecture in Sichuan Province....
in Sichuan
Sichuan
' , known formerly in the West by its postal map spellings of Szechwan or Szechuan is a province in Southwest China with its capital in Chengdu...
Province.
After liftoff, Chang'e 1 made three orbits around the Earth, a burn at perigee
Apsis
An apsis , plural apsides , is the point of greatest or least distance of a body from one of the foci of its elliptical orbit. In modern celestial mechanics this focus is also the center of attraction, which is usually the center of mass of the system...
extending the orbit's apogee
Apsis
An apsis , plural apsides , is the point of greatest or least distance of a body from one of the foci of its elliptical orbit. In modern celestial mechanics this focus is also the center of attraction, which is usually the center of mass of the system...
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
Polar orbit
A polar orbit is an orbit in which a satellite passes above or nearly above both poles of the body being orbited on each revolution. It therefore has an inclination of 90 degrees to the equator...
around the Moon, with burns at the perilune of the first three orbits decreasing the apolune 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
' also known in the West by its postal map spelling Tsingtao, is a major city with a population of over 8.715 million in eastern Shandong province, Eastern China. Its built up area, made of 7 urban districts plus Jimo city, is home to about 4,346,000 inhabitants in 2010.It borders Yantai to the...
and Kashgar
Kashgar
Kashgar or Kashi is an oasis city with approximately 350,000 residents in the western part of the Xinjiang Uyghur Autonomous Region of the People's Republic of China. Kashgar is the administrative centre of Kashgar Prefecture which has an area of 162,000 km² and a population of approximately...
, as the first use of the Chinese Deep Space Network
Chinese Deep Space Network
The Chinese Deep Space Network is a network of large antennas and communication facilities that supports the lunar and interplanetary spacecraft missions of China....
. The ESA Maspalomas Tracking Station
Maspalomas Station
Maspalomas Station is an INSA-operated, ESTRACK radio antenna station for communication with spacecraft located at the southern area of Gran Canaria island, on the INTA campus. The site hosts a 15-metre antenna with reception in S- and X-band and transmission in S-band.-External links:* *...
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 MoonMoon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
, 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 1.50°S 52.36°E. 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 2,350 kg, with a 130 kg payload, carrying 24 instruments including a Charge-coupled deviceCharge-coupled device
A charge-coupled device is a device for the movement of electrical charge, usually from within the device to an area where the charge can be manipulated, for example conversion into a digital value. This is achieved by "shifting" the signals between stages within the device one at a time...
(CCD) stereo camera
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 images, a process known as stereo photography. Stereo...
, microprobe instruments, and a high-energy solar particle detector.
- Stereo camera with an optical resolutionOptical resolutionOptical 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 a lens and recording and display components...
of 120 m and spectrometerSpectrometerA spectrometer is an instrument used to measure properties of light over a specific portion of the electromagnetic spectrum, typically used in spectroscopic analysis to identify materials. The variable measured is most often the light's intensity but could also, for instance, be the polarization...
imager operating at wavelengthWavelengthIn physics, the wavelength of a sinusoidal wave is the spatial period of the wave—the distance over which the wave's shape repeats.It is usually determined by considering the distance between consecutive corresponding points of the same phase, such as crests, troughs, or zero crossings, and is a...
s of 0.48 µm to 0.96 µm. - Laser altimeterAltimeterAn altimeter 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 underwater.-Pressure altimeter:...
with 1064 nm, 150 mJJouleThe joule ; symbol J) is a derived unit of energy or work in the International System of Units. It is equal to the energy expended in applying a force of one newton through a distance of one metre , or in passing an electric current of one ampere through a resistance of one ohm for one second...
laser, a range resolution of 1 m and a spot size of 300 m. - Imaging spectrometer
- Gamma and X-ray spectrometer working in an energy range of 0.5 to 50 keVElectronvoltIn physics, the electron volt is a unit of energy equal to approximately joule . By definition, it is equal to the amount of kinetic energy gained by a single unbound electron when it accelerates through an electric potential difference of one volt...
for X-rays and 300 keV to 9 MeV for gamma rayGamma rayGamma radiation, also known as gamma rays or hyphenated as gamma-rays and denoted as γ, is electromagnetic radiation of high frequency . Gamma rays are usually naturally produced on Earth by decay of high energy states in atomic nuclei...
s. - Microwave radiometerMicrowave radiometerA microwave radiometer is a radiometer that measures energy emitted at sub-millimetre-to-centimetre wavelengths known as microwaves. Their primary application has been onboard spacecraft measuring atmospheric and terrestrial radiation, and they are mostly used for meteorological or oceanographic...
detecting 3, 7.8, 19.35 and 37 GHzHertzThe hertz is the SI unit of frequency defined as the number of cycles per second of a periodic phenomenon. One of its most common uses is the description of the sine wave, particularly those used in radio and audio applications....
with a maximal penetration depth of 30, 20, 10, 1 m and a thermalThermalA thermal column is a column of rising air in the lower altitudes of the Earth's atmosphere. Thermals are created by the uneven heating of the Earth's surface from solar radiation, and are an example of convection. The sun warms the ground, which in turn warms the air directly above it...
resolution of 0.5 K. - High energy particle detector and two solar windSolar windThe solar wind is a stream of charged particles ejected from the upper atmosphere of the Sun. It mostly consists of electrons and protons with energies usually between 1.5 and 10 keV. The stream of particles varies in temperature and speed over time...
detectors capable of the detection of electronElectronThe electron is a subatomic particle with a negative elementary electric charge. It has no known components or substructure; in other words, it is generally thought to be an elementary particle. An electron has a mass that is approximately 1/1836 that of the proton...
s and heavy ionIonAn ion is an atom or molecule in which the total number of electrons is not equal to the total number of protons, giving it a net positive or negative electrical charge. The name was given by physicist Michael Faraday for the substances that allow a current to pass between electrodes in a...
s up to 730 MeV.
See also
- Exploration of the MoonExploration of the MoonThe physical exploration of the Moon began when Luna 2, a space probe launched by the Soviet Union, made an impact on the surface of the Moon on September 14, 1959. Prior to that the only available means of exploration had been observation. The invention of the optical telescope brought about the...
- List of future lunar missions
- Robotic exploration of the MoonRobotic exploration of the Moon-Pioneer program:*Pioneer 0 – failure – orbiter*Pioneer 1 – failure – orbiter*Pioneer 2 – failure – orbiter*Pioneer 3 – failure – flyby...
External links
- CLEP Official site
- Chang'e 1 Mission Profile by NASA's Solar System Exploration
- Encyclopedia Astronautica
- The Scientific Objectives of Chinese Lunar Exploration Project by Ouyang Ziyuan
- YouTube video of launch
- Chinese State Media Coverage (CCTV) in English
- Europe, China Cooperate To Radio Lunar Probe
- FACTBOX - Reuters - Planned lunar missions
- Reuters: CHRONOLOGY - Five key dates in the race to the Moon