My Science School

Chang'e 4 is a robotic spacecraft mission, part of the second phase of the Chinese Lunar Exploration Program. China achieved humanity's first soft landing on the far side of the Moon, on 3 January 2019

The launch mass of Chang’e-4 spacecraft is about 3,780 kg. The mass of lander is about 1,200 kg and that of rover is 140 kg. As per the mission design, the rover is expected to explore the lunar surface for a period of three months while the lander’s mission would last for a full year. The lander has released a rover, called Yutu-2 (Jade Rabbit) for performing experiments in the Von Karman Crater. This is a large lunar impact crater which is about 180 km in diameter. This basin is located within a very big impact crater called the South Pole–Aitken basin (2,500 km in diameter and 13 km deep).

One of the most interesting experiments as a part of this mission was the one designed by the scientists from Chongqing University. This “mini lunar biosphere” experiment carried an 18cm bucket-like container holding air, water and soil. Inside this unit was carried cotton, arabidopsis – a small, flowering plant of the mustard family – and potato seeds, as well as fruit-fly eggs and yeast. The images sent back by the probe show a cotton plant has grown well, but so far none of the other plants had sprouted. Now, this experiment is over and sprouted cotton would decay in the container. This is for the first time in history that a biological matter has been flown to moon. Earlier, plants have been grown on the International Space Station (ISS).

Credit : ORF.online

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Tiangong-1 is a single-module space station operated by the China National Space Administration. The module was launched in 2011 and hosted two crews of taikonauts (Chinese astronauts) in 2012 and 2013. Since China's space agency discloses less information about its missions than other space agencies, the details surrounding the space station are not widely known.

The orbit of the space station passes over most of the civilized world, with the exclusion of northern latitudes that include the United States, Russia and Canada, as well as the extreme south of the world, including Antarctica and the tip of South Africa. However, most of the Earth is covered by water, reducing the chances of a crash in a populated area.

Tiangong-1 (whose name means "Heavenly Palace") weighs about 8.5 metric tons, and is about 34 feet long by 11 feet wide (10.4 meters by 3.4 meters). It contains an experiment module — where the astronauts live and work — and a resource module that contains propellant tanks and rocket engines.

The module was placed in low Earth orbit at about 217 miles (350 kilometers), at a slightly lower altitude than the International Space Station. Two solar arrays power the station, and it can house three astronauts. 

A primary goal for the module was to help the Chinese practice space dockings, which is an important skill for nations looking to build larger space stations or to send multiple spacecraft to the moon, Mars or other locations in the solar system.

Credit : Space.com

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Chang’e 1 was China’s first spacecraft to travel beyond Earth’s orbit. Its mission included stereoscopic imaging of the lunar surface, assaying the chemistry of the surface, and testing technologies that could be used in expanding the Chinese national space program to the Moon. 

Chang’e 1 carried eight instruments. A stereo camera and a laser altimeter developed a three-dimensional map of the surface with the camera tilting forward, down, and aft to illuminate three charge-coupled device (CCD) arrays. The interferometer spectrometer imager used a special lens system to project light onto an array of CCDs. X-ray and gamma-ray spectrometers measured radiation emitted by naturally decaying heavy elements or produced in response to solar radiation. These spectral data helped quantify the amounts of minerals on the lunar surface. The microwave radiometer detected microwaves emitted by the Moon itself and thus measured the thickness of the debris layer, or regolith, that fills the huge basins called maria. One aim of the regolith investigations was understanding how much helium-3 may be on the Moon. Helium-3 is a trace element in the solar wind, and the lunar surface has absorbed larger quantities of helium-3 than have been found on Earth. If mining on the Moon ever becomes practical, helium-3 would be a valuable fuel for nuclear fusion power. Other instruments monitored the solar wind and the space environment.

Credit : Britannica

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Tianwen-1 is an interplanetary mission by the China National Space Administration (CNSA) to send a robotic spacecraft to Mars, consisting of 5 parts: an orbiter, deployable camera, lander, drop camera, and the Zhurong rover. The spacecraft, with a total mass of nearly five tons, is one of the heaviest probes launched to Mars and carries 13 scientific instruments. It is the first in a series of planned missions undertaken by CNSA as part of its Planetary Exploration of China program.

The mission was launched from the Wenchang Spacecraft Launch Site on 23 July 2020 on a Long March 5 heavy-lift launch vehicle. After seven months of transit through the inner Solar System, the spacecraft entered Martian orbit on 10 February 2021. For the next three months the probe studied the target landing sites from a reconnaissance orbit. On 14 May 2021, the lander/rover portion of the mission successfully touched down on Mars, making China the third nation to both land softly on and establish communication from the Martian surface, after the Soviet Union and the United States.

The Tianwen-1 mission was the second of three Martian exploration missions launched during the July 2020 window, after the United Arab Emirates Space Agency's Hope orbiter, and before NASA's Mars 2020 mission, which landed the Perseverance rover with the attached Ingenuity helicopter drone.

China's Mars program started in partnership with Russia. In November 2011, the Russian spacecraft Fobos-Grunt, destined for Mars and Phobos, was launched from Baikonur Cosmodrome. The Russian spacecraft carried with it an attached secondary spacecraft, the Yinghuo-1, which was intended to become China's first Mars orbiter (Fobos-Grunt also carried experiments from the Bulgarian Academy of Sciences and the American Planetary Society). However, Fobos-Grunt's main propulsion unit failed to boost the Mars-bound stack from its initial Earth parking orbit and the combined multinational spacecraft and experiments eventually reentered the atmosphere of Earth in January 2012. China subsequently began an independent Mars project.

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