Live: Jade Rabbit rover and lander photograph each other
Editor’s note: After successfully landing on the Moon and separating from each other, China’s first moon rover Jade Rabbit and lander have photographed each other, marking the complete success of the Chang’e 3 mission.
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[0:10] That’s all for today’s live report. Thank you for staying with us.
Armstrong’s small step was a giant leap for mankind. The development of China’s space technology and space exploration will benefit all mankind. All the institutions and technicians involved in this project know this. I think we should have not only the spirit to catch up with others, but also the passion to benefit the world.
Latecomers surpass old-timers” is a Chinese idiom from 2000 years ago, which actually means firewood piles up and the newest firewood is put on the top. Now China’s Chang’e 3 has landed on the moon and the Jade Rabbit has rolls onto the Moon’s surface. In contrast with the 12 failures of Soviet Russia and the three failures of the United States, China has succeeded in a single take. How marvelous! This is really “late-comers surpassing old-timers”. China’s success has given the old idiom a new definition: I TKO (technologically knock out) you, you forthgoers have nothing to show off!!
Although the U.S. and the Soviet Union have already carried out moon landings, I still feel very excited. I hope that China will land a craft on Mars in the near future!
[23:54] Chinese President Xi Jinping and other state leaders are shaking hands with the staff in the Beijing Aerospace Control Center to give their thanks for the success of the mission.
[23:50] China’s Vice Premier Ma Kai is reading a message of congratulations for the mission.
[23:48] Ma Xingrui, head of China’s space exploration body and chief commander of the lunar program said that the data has been transmitted fully. The photos are clear. The rover and lander are working properly and have completed their goals. The mission has been a complete success.
[23:45] The photos are due to be displayed very soon.
[23:43] The first, second and third photographs are currently being sent from the Moon.
[23:41] Chinese President Xi Jinping and Premier Li Keqiang as well as other state leaders are watching the lander and the rover photograph each other from the Beijing Aerospace Control Center (BACC).
[23:37] Ten minutes to go…
[23:27] Yutu will take two pictures of the front side of Chang’e 3. This is the side where the Chinese national flag is painted. One of the pictures will be taken from ten meters away, while the other will be clicked from a distance of 18 meters.
[23:25] Jia Yang, deputy chief designer of China’s first lunar rover, said that Jade Rabbit is a six-wheel lunar rover, composed of nine sections. It is very small, has a low power consumption and high integration. Jade Rabbit is a highly intelligent robot. Its comprehensive electronic subsystem is equivalent to a human brain. The GNC system is equivalent to the five senses. Its thermal control regulates temperature. The mechanical arm acts like a human arm, the wheels like feet, and the structure like a skeleton.
[23:22] It has been one of the most anticipated tasks of the mission since the lander and rover separated. The rover Jade Rabbit will move to five different locations to capture images of Chang’e 3 from different angles.
[23:20] This will be the first time, people on the Earth will see what the two lunar explorers look like on the lunar surface.
[23:18] The Chang’e 3 lander and Jade Rabbit rover are readying to take pictures of each other.
[23:15] Jia Yang, Deputy Chief Engineer, Chang’e 3, said, “The lander and the rover will take pictures of each other about 10 meters apart. As the separation was completed in the morning hours, the rover will follow the track on the right circle of the lander so that the lander is better illuminated in the photos.”
Chang’e 3’s successful landing on the moon has not only made the thousand-year legend of Chang’e going to the moon a reality, but has also made the Chinese mainland a space super power. This is a historic moment.
[23:00] China’s first moon rover, Yutu, or Jade Rabbit, and the lander are scheduled to take photos of each other Sunday night, a move that will mark the complete success of the country’s Chang’e 3 lunar probe mission.
[21:35] Thank you for staying with us. Please come back for tomorrow’s mission.
[21:23] The Jade Rabbit rover will start its survey of the Moon surface in eight hours.
[21:20] The BACC announces the successful unfolding of the solar panels.
[21:16] The solar panels have been unfolded.
[21:13] Staff at the BACC are congratulating each other.
[21:12] The Chang’e 3 has successfully completed its soft-landing on the Moon.
[21:11] The lander has landed.
[21:11] The lander is hovering 100 m above the Moon surface for 30 seconds.
[21:10] The lander has confirmed its obstacle-free landing zone.
[21:09] The first image of the Moon surface has been transmitted.
[21:08] The lander will now descend 600 m within 20 seconds.
[21:07] The Chang’e 3 has started its 720-second power reduction.
[21:06] The downward-looking camera has started filming.
[21:04] The 7500 Newton rocket engine has been switched on.
[21:02] The rocket is working on a reduced power.
[21:00] The power descend begins.
[20:56] A panoramic camera installed on the lunar rover will film the land and the Chinese national flag on it. Another mission of the camera is to explore the moon surface.
[20:53] @Zhishan8musheng: Wah! I love it when the country gets stronger. We had astronauts conducting lectures in space earlier and Chang’e landing on the moon today. We get to see the live feed blessed by modern technology. My four-year-old is already an astronomy fan thanks to China’s space exploration. I thank you all for instilling the sense of science into his brain.
[20:50] Ten minutes to go…
[20:29] After Chang’e 3’s successful landing, BACC will discuss whether the rover and the lander will separate immediately. Even so, the Yutu (Jade Rabbit) rover will take a few hours to move out of the lander and appear on moon surface at 6:00 am on Sunday.
[20:28] Currently, staff at BACC are making final preparations to confirm Chang’e 3’s all parameters, including its flight speed, actual time and location of the lunar impact.
[20:26] Zhou Jianliang, deputy chief engineer of Beijing Aerospace Control Center (BACC), said on Saturday morning that Chang’e 3 is scheduled to ignite the rockets at 9:00 pm to start the soft-landing process. He added the process will take 12 minutes.
[20:23] The entire process of soft-landing will last 12 minutes and it will be performed by the probe itself, with “practically zero” chance of manual intervention being required. The Chang’e 3 mission has so far proceeded as planned.
Chang’e 3 to face five major difficulties
1. Can it land on the specified Sinus Iridum?
Previously, Chang’e 1 and Chang’e 2 satellites had solved the technical problems of orbiting the moon. This time, Chang’e 3 lunar probe will solve the problem of whether it can land on the designated area after successfully orbiting the moon, Wu explained.
“This is just like driving a car on a highway. If you drive too slowly, you will lose time; if you drive too fast, you won’t be able to stop the car immediately. Or miss the destination, or run into it, and won’t complete its mission,” said Wu, adding that a proper “braking” time and distance is key in the Chang’e 3 lunar exploration mission.
2. It’s not easy to choose the final landing location
Scientists have chosen the Sinus Iridum, also known as the Bay of Rainbows, for the landing location of Chang’e 3. “The surface of the moon is macroscopically flat, but we’re not very clear what its terrain is really like regionally. We don’t know where the lunar probe will finally land,” said Wu.
“Although we had taken a lot of measures, the risk is still big. There are numerous stones, rocks, craters and ditches on the moon, which the Chang’e 3 lunar probe will possibly encounter,” Wu explained.
3. Lack of air friction can be used to slow down the landing
There’s no air on the moon, which ensures that landing on the moon is completely different from doing so on earth. It is a soft landing in a vacuum state.
“No air means no air friction can be used to slow down the lunar probe, and a traditional rocket engine and propulsion system cannot complete this mission,” said Sun Zezhou, chief designer of the Chang’e 3 lunar probe system.
Sun said that the newly developed 7500-type variable thrust engine is capable of continuously and precisely adjusting and controlling the landing speed. ”But, as the new engine is used for the first time, a successful performance awaits further testing,” said Sun.
4. Possibility of artificial intervention is almost zero
The landing process needs real-time measurements and adjustments of the lunar probe’s speed and height. “The entire process must be completed within a very short period of time and it relies entirely on the lunar probe itself. Independent navigation control is very difficult,” Sun said.
The 15-km landing process is described as the most “soul-stirring stage” by scientists. A series of crucial movements will be executed in this stage, including slowing down, designating the landing location and landing softly. The possibility of artificial intervention is almost zero at this point.
“No artificial intervention can keep up with it. We can do nothing but set the program in advance,” said Tan Mei, vice general commander of the Chang’e 3 lunar probe system.
5. Dust may cling to the lunar probe and cause mechanical faults
Clouds of lunar dust may rise up during the Chang’e 3 landing. The dust clinging onto the surface of the lunar probe may cause decreased sensitivity of the optical system and cause for the mechanical structures to get stuck, Tan explained.
In addition, the huge impact energy from the surface of the moon and the plume from the lunar probe itself form the biggest threats to a safe soft landing. “Whether the Chang’e 3 buffer mechanism can stand the final test is still uncertain” said Tan.
Vital moves of the Chang’e 3
December 10- Descends from the 100 km-high lunar circular orbit at 9:20 p.m. to an elliptical orbit with its nearest point about 15 km away from the moon’s surface.
December 6- Enters the 100 km-high lunar circular orbit at 5:53 p.m. after 361 seconds of precise braking by the variable thrust engine.
December 2- Blasts off from the Xichang Satellite Launch Center at 1:30 a.m.; finishes the first orbital trimming in its trajectory along the earth-moon transfer orbit. at 3:50 p.m..
Where will the Chang’e 3 land?
The Chang’e 3 will land in the moon’s Sinus Iridum region (Latin for “Bay of Rainbows”). The bay’s selenographic coordinates are 44.1°N, 31.5°W, and it is a plain of basaltic lava that forms a northwestern extension to the Mare Imbrium. It was formed 3.9 billion years ago due to a collision.
The plain basin and its surrounding mountains are considered one of the most beautiful features found on the Moon, reminiscent of rainbow arcs. Hence it was given the name “Bay of Rainbows” by 17th century Italian astronomer Giovanni Riccioli.
About China’s first moon rover ‘Yutu’
The rover has two wings, stands on six wheels, and weighs 140 kg. It is a highly efficient and integrated robot that can withstand the vast temperature variations of the moon.
Earlier, China initiated a worldwide name competition for its first-ever moon rover. Nearly 650 thousand online voters favored for “Yutu.”
In Chinese folklore, Yutu is the white pet rabbit of Chang’e, the moon goddess who has lent her name to the Chinese lunar mission.
Legend has it that, after swallowing a magic pill, Chang’e took her pet and flew toward the moon, where she became a goddess, and has lived there with the white jade rabbit ever since.
NASA reviews the moon landings
Timeline of China’s lunar program
China’s lunar mission is divided into three stages: orbiting, landing, and return. Following is the timeline of China’s lunar mission development.
1998 Commission for Science, Technology and Industry for National Defense (COSTIND) begins planning the lunar mission, tackling major scientific and technological problems;
2004 January – lunar orbiter project is formally established;
February – mission is named “Project Chang’e” after a mythical Chinese goddess who flew to the moon;
2007 Oct. 24 – Chang’e 1 is successfully launched;
Nov. 7 – Chang’e 1 enters lunar orbit;
Nov. 26 – a clip of the voice of the probe and a Chinese song “Ode to the Motherland” are sent back from orbit. China’s first picture of the lunar surface is published by Xinhua News Agency;
2008 Jan. 31 – COSTIND publishes the first picture of the lunar polar region taken by Chang’e-1;
October – the State Council, China’s Cabinet, approves the Chang’e 2 mission;
Nov. 12 – based on data collected by Chang’e 1, the first lunar hologram with a resolution of 7 meters is published;
2009 March 1 – Chang’e 1 impacts the moon under control;
2010 Oct. 1 – Chang’e 2 is sent into space aboard a Long March-3C carrier rocket from southwest China’s Xichang satellite launch center;
Oct. 9 – Chang’e 2 enters 100-km circular lunar orbit;
Oct. 26 – Chang’e 2 enters lower, elliptical orbit; prepares to photograph Sinus Iridium;
Oct. 29 – Chang’e 2 photographs Sinus Iridium and returns to a higher orbit;
Nov. 8 – pictures of Sinus Iridium published by the State Administration for Science, Technology and Industry for National Defence (SASTIND);
2011 April 1 – Chang’e 2 completes all six engineering objectives and four scientific missions. Its design lifetime expires;
April to the end of May – Chang’e-2 surveys south and north poles of the moon, and takes high-resolution pictures of the chosen landing site for Chang’e 3;
Aug. 25 – For the first time in history, from lunar orbit a space craft enters the second Lagrange Point (L2) orbit, where gravity of the sun and Earth balance the orbital motion of the satellite;
2012 Feb. 6 – SASTIND publishes a lunar hologram with a resolution of 7 meters;
Dec. 13 – Chang’e 2 arrives in deep space 7 million km away from Earth, and surveys the Tout asteroid;
2013 Dec. 2 – Chang’e 3, the spacecraft carrying China’s rover to the moon, is launched.
Facts on the moon
The Moon is the Earth’s only natural satellite and the only astronomical body other than Earth ever visited by human beings. The moon reflects light from the sun and is about 4.6 billion years old.
The moon’s average radius (distance from its center to its surface) is 1,079.6 miles (1,737.4 kilometers), about 27 percent of the radius of Earth.
The moon has a mass (amount of matter) of 8.10 x 1019 tons (7.35 x 1019 metric tons). Its mass in metric tons would be written out as 735 followed by 17 zeroes. Earth is about 81 times that massive. The moon’s density (mass divided by volume) is about 3.34 grams per cubic centimeter, roughly 60 percent of Earth’s density.
Because the moon has less mass than Earth, the force due to gravity at the lunar surface is only about 1/6 of that on Earth.
The average distance from the center of Earth to the center of the moon is 238,897 miles (384,467 kilometers). That distance is growing — but extremely slowly. The moon is moving away from Earth at a speed of about 1 1/2 inches (3.8 centimeters) per year.
The temperature at the lunar equator ranges from extremely low to extremely high — from about -280 degrees F (-173 degrees C) at night to +260 degrees F (+127 degrees C) in the daytime. In some deep craters near the moon’s poles, the temperature is always near -400 degrees F (-240 degrees C).
The moon has no life of any kind. Compared with Earth, it has changed little over billions of years.
A person on Earth looking at the moon with the unaided eye can see light and dark areas on the lunar surface. The light areas are rugged, cratered highlands known as terrae (TEHR ee). The word terrae is Latin for lands. The highlands are the original crust of the moon, shattered and fragmented by the impact of meteoroids, asteroids, and comets. Many craters in the terrae exceed 25 miles (40 kilometers) in diameter. The largest is the South Pole-Aitken Basin, which is 1,550 miles (2,500 kilometers) in diameter.
The dark areas on the moon are known as maria (MAHR ee uh). The word maria is Latin for seas; its singular is mare (MAHR ee). The term comes from the smoothness of the dark areas and their resemblance to bodies of water. The maria are cratered landscapes that were partly flooded by lava when volcanoes erupted. The lava then froze, forming rock. Since that time, meteoroid impacts have created craters in the maria.
The moon has no substantial atmosphere, but small amounts of certain gases are present above the lunar surface. People sometimes refer to those gases as the lunar atmosphere. This “atmosphere” can also be called an exosphere, defined as a tenuous (low-density) zone of particles surrounding an airless body. Mercury and some asteroids also have an exosphere.