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Model of the next generation rocket for manned spaceflight displayed at Zhuhai Airshow.new rockets using cluster of yf-100 engines like falcon 9 design
China Outer Space Science, Technology and Explorations: News & Updates
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China's Tianhe Project satellite to debut at Airshow China 2018
(People's Daily) 08:08, November 06, 2018
(Photo: sast.net)
China has officially launched the development of satellites and rockets of the Tianhe Project, which aims to move water vapor in the sky from the damp west part of the country to the arid north.
Tianhe can be translated as “river in the sky.”
A model of an observation satellite that is part of the first phase of the Tianhe Project will make its debut at the 12th China International Aviation and Aerospace Exhibition (Airshow China 2018), according to Shanghai Academy of Spaceflight Technology (SAST).
Liu Weiliang, the general commander of the satellite team, said that the Tianhe Project satellites and rockets are developed by SAST.
SAST plans to launch the first batch of “Tianhe-1” satellites by 2020 and carry out a demonstration of the viability of the Tianhe Project.
SAST is also planning to complete a six-satellite network by 2022, providing technical support for the construction of an “air corridor” transmitting water vapor to arid north China.
Chinese scientist and academician Wang Guangqian and his team found that there are water vapor channels from the West Indian Ocean, the East Indian Ocean, the Yunnan-Guizhou Plateau, and Central Asia. These cloud water resources have great potential for development.
The Tianhe Project is a special project for the development and utilization of air water resources. Through scientific analysis of the distribution and movement patterns of water in the atmosphere, a new type of manual intervention technology will be adopted to realize the overall regulation and utilization of air water resources and surface water resources in different regions.
According to Zhu Wei, the chief designer of Tianhe satellite, the Tianhe-1 satellite is equipped with payloads such as microwave temperature and humidity meters, precipitation measurement radar and cloud water detectors. The satellite can achieve high-precision detection through a combination of active and passive measures.
Among these payloads, the microwave temperature and humidity meters can accurately detect the vertical distribution of atmospheric temperature and humidity, capturing the distribution of water vapor in the air. The precipitation measurement radar can monitor the three-dimensional distribution of precipitation. The water vapor detector can make an atmospheric cloud map and detect the surface environmental characteristics of the Sanjiangyuan area on the Tibetan Plateau of Qinghai Province, the origin of much of the water vapor that will be moved to more arid areas.
The 12th China International Aviation and Aerospace Exhibition will be held at the Zhuhai International Airshow Center from November 6 to 11.
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ASTRONOMY AND ASTROPHYSICS | 02 NOVEMBER 2018
Dark space cloud caught donning halo of hydrogen molecules
For the first time, a Galactic cloud is seen producing an ingredient that is fundamental in star formation.
A chilly cloud of molecular gas in the Milky Way is giving astronomers a rare look at one of the earliest steps in star formation.
The smallest, most fundamental molecules in the Universe are created when two hydrogen atoms bond to form hydrogen molecules (H2). This process usually takes place in cold, dark clouds. But the molecule’s formation is rarely observed, because it’s hard to distinguish atomic and molecular hydrogen from other types of molecules and from each other.
Pei Zuo and Di Li at the National Astronomical Observatories of the Chinese Academy of Sciences in Beijing and their colleagues used the Arecibo radio telescope in Puerto Rico to observe dark clouds. The researchers found that one cloud had an outer ‘shell’ of atomic hydrogen that was being converted into molecular hydrogen — the first such detection of a dark cloud’s birth.
Further analysis of the rate of H2 formation suggested that the cloud is roughly six million years old. This finding could help to constrain models of star, planet and galaxy formation, the authors write.
Dark space cloud caught donning halo of hydrogen molecules : Research Highlights | Nature
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China developing reusable space rocket
Source: Xinhua| 2018-04-30 16:37:16|Editor: Chengcheng
BEIJING, April 30 (Xinhua) -- China aims to recover the first stage of the Long March-8 carrier rocket, which is still under development and is expected to make its maiden flight around 2021, according to a Chinese rocket expert.
It was part of China's endeavors to develop reusable space vehicles, Long Lehao, chief designer of carrier rockets at the China Academy of Launch Vehicle Technology, told a space conference in Harbin, capital of northeast China's Heilongjiang Province.
The Long March-8 rocket will have two stages and two boosters: the first stage and boosters are expected to be retrieved through vertical landing, said Long, who is also an academician of the Chinese Academy of Engineering.
If successful, the new rocket would provide commercial launch services to customers around the globe, Long said.
"China's aerospace industry is making efforts to develop low-cost vehicles that can enter space rapidly to support future large-scale space exploration and promote a commercial space industry," Long said.
Bao Weimin, director of the Science and Technology Commission of the China Aerospace Science and Technology Corporation and an academician of the Chinese Academy of Sciences, said China's reusable carrier vehicle will use technologies different from those of U.S. commercial space firm SpaceX.
"As the current Long March 2, 3, 4 series rockets are fueled by toxic propellants, they cannot be recycled. But we are developing technologies to precisely control the fall of the rocket remains to ensure safety," Long said.
That effort is important as residents in possible landing areas have to be evacuated at every launch. As China's aerospace activities become more frequent, with 36 launches planned this year, precise control of falling rocket remains could save a lot of trouble.
Long also introduced the development roadmap for China's space transportation system.
Around 2025, reusable suborbital carriers will be successfully developed and suborbital space travel will be realized. Around 2030, rockets with two reusable stages will be developed. Around 2035, carrier rockets will be completely reusable which could realize the dream of space travel for ordinary people.
A future generation of carrier rockets will be put into use around 2040 and hybrid-power reusable carriers will be developed. Space vehicles will be more diverse, intelligent, reliable, low-cost, efficient and convenient.
"Those targets are not easy to achieve, and lots of technological difficulties must be solved," Long said.
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China developing new-generation manned rocket, spacecraftModel of the next generation rocket for manned spaceflight displayed at Zhuhai Airshow.
Source: Xinhua| 2018-11-06 23:21:54|Editor: yan
ZHUHAI, Nov. 6 (Xinhua) -- China is developing a new-generation manned rocket and spacecraft for its lunar exploration, said an expert at the 12th China International Aviation and Aerospace Exhibition Tuesday in Zhuhai, Guangdong Province.
The rocket will be used to fly around the moon in China's manned lunar missions. It will also help astronauts build a moon base with the Long March-9 carrier rocket in the future, said Wang Xiaojun, who is in charge of the rocket system of the Long March-7.
With a takeoff weight of 2,000 tonnes, the new rocket is expected to have carrying capabilities of 25 tonnes for lunar trajectories, 70 tonnes for low-Earth orbit.
Hot-fire tests of the rocket's engines have been conducted recently, said Wang.
The new manned spacecraft is nine meters long, with a maximum launch weight of 23 tonnes. It will have a re-entry module and a service module.
With low cost and high reliability, it will be a safe and livable spacecraft to be used in China's manned lunar missions and manned deep-space expeditions.
China launched its first manned mission in 2003, becoming the third country in the world to independently develop manned spacecraft after Russia and the U.S.
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China to launch small communication satellites for commercial use for the first time
By He Weiwei
2018-11-10 16:11 GMT+8
In a world where the Internet is a virtual necessity, China is helping bring it to areas where it's not always reliable.
China Great Wall Industry Corporation (CGWIC) announced a customized new system of small communication satellites for overseas users, on the sidelines of Airshow China 2018 held from November 6 to 11 in Zhuhai City.
The system is based on the DFH-4F SMALL GEO Platform, which enables high-speed Internet services for overseas users in remote areas.
This is the first time that China will launch small communication satellites for commercial use, which have an operation life of 15 years, roughly the same as other medium or large-sized communication satellites. However, it's more cost-efficient than large ones, and takes a shorter time to develop.
CGWIC chairman Liu Qiang (R) holds a model of a small communication satellite, whose development is estimated to take two years. /CGTN Photo
“For some island countries, mountainous areas, or underdeveloped areas in transportation or infrastructure... people will have access to high-speed Internet services," said CGWIC chairman Liu Qiang. "(It's) thanks to satellite communications and some small ground stations."
Liu said so far the company has delivered 13 large satellites in orbit for international users, including Nigeria, Pakistan, Venezuela, and Belarus. The new deal is seen as another step toward China's “going global” strategy in space and satellite industry.
CGWIC is the only company authorized by the Chinese government to provide commercial launching services and satellite systems for international users. The announcement follows a signing ceremony with APT Satellite Company Limited, a broadcasting and telecommunications services provider based in Hong Kong.
By He Weiwei
2018-11-10 16:11 GMT+8
In a world where the Internet is a virtual necessity, China is helping bring it to areas where it's not always reliable.
China Great Wall Industry Corporation (CGWIC) announced a customized new system of small communication satellites for overseas users, on the sidelines of Airshow China 2018 held from November 6 to 11 in Zhuhai City.
The system is based on the DFH-4F SMALL GEO Platform, which enables high-speed Internet services for overseas users in remote areas.
This is the first time that China will launch small communication satellites for commercial use, which have an operation life of 15 years, roughly the same as other medium or large-sized communication satellites. However, it's more cost-efficient than large ones, and takes a shorter time to develop.
“For some island countries, mountainous areas, or underdeveloped areas in transportation or infrastructure... people will have access to high-speed Internet services," said CGWIC chairman Liu Qiang. "(It's) thanks to satellite communications and some small ground stations."
Liu said so far the company has delivered 13 large satellites in orbit for international users, including Nigeria, Pakistan, Venezuela, and Belarus. The new deal is seen as another step toward China's “going global” strategy in space and satellite industry.
CGWIC is the only company authorized by the Chinese government to provide commercial launching services and satellite systems for international users. The announcement follows a signing ceremony with APT Satellite Company Limited, a broadcasting and telecommunications services provider based in Hong Kong.
JSCh
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China is about to visit uncharted territory on the moon
One Chinese mission will bring back the first lunar rock samples in more than four decades
BY LISA GROSSMAN
7:00AM, NOVEMBER 11, 2018
HELLO FROM THE OTHER SIDE The farside of the moon, shown in this picture from NASA’s Lunar Reconnaissance Orbiter, is due to get its first robotic visitor soon. China’s Chang’e-4 spacecraft will launch for the region in December.
GODDARD SPACE FLIGHT CENTER/NASA, ARIZONA STATE UNIVERSITY
China is about to make space history. In December, the country will launch the first spacecraft ever to land on the farside of the moon. Another craft, slated for takeoff in 2019, will be the first to bring lunar rocks back to Earth since 1976.
These two missions — the latest in China’s lunar exploration series named after the Chinese moon goddess, Chang’e — are at the forefront of renewed interest in exploring our nearest celestial body. India’s space agency as well as private companies based in Israel and Germany are also hoping for robotic lunar missions in 2019. And the United States aims to have astronauts orbiting the moon starting in 2023 and to land astronauts on the lunar surface in the late 2020s.
The time is ripe for new lunar exploration. Despite decades of study, Earth’s only natural satellite still contains mysteries about its formation as well as clues to the history of the solar system (SN: 4/15/17, p. 18). “There are too many things we don’t know,” says planetary scientist Long Xiao of China University of Geosciences in Wuhan. He is a coauthor of two studies published in June and July in the Journal of Geophysical Research: Planets describing the landing sites of the new Chinese missions, Chang’e-4 and -5.
To figure out what secrets the moon may still be hiding, scientists are excited to get their hands on new rock samples. The Chang’e-5 sample return mission “no doubt will have additional rock types that we haven’t sampled yet,” says planetary scientist David Blewett of Johns Hopkins University Applied Physics Laboratory in Laurel, Md. “If you came to the Earth and landed in Great Britain and made all your conclusions about the Earth from what you saw … you really wouldn’t have the whole picture.”
Journey to the dark side
The Chang’e-4 spacecraft includes a lander and a rover that were originally built as backups for the 2013 Chang’e-3 mission, which marked China’s first moon landing — and the first moon landing at all since the 1970s (SN Online: 12/16/13). The uncrewed Chang’e-3 lander-rover duo touched down in a vast lava plain in the north known as Mare Imbrium, where the craft measured the composition and thickness of the lunar soil and discovered what might be a new type of basalt, or lava-based rock.
This time, China has its sights set on lunar regions never before explored. Chang’e-4 is aiming for the moon’s largest, deepest and possibly oldest known feature created by an impact, the South Pole–Aitken basin, on the lunar farside, which always faces away from Earth. The whole basin, which is 2,500 kilometers wide and up to 8.2 kilometers deep, is too big for the rover to explore. So Chang’e-4 is shooting for the 186-kilometer-wide Von Kármán crater within the larger basin for a cosmic hole in one.
DARK AND DEEP The South Pole-Aitken basin on the farside of the moon, shown in blue tones in elevation data from NASA’s Lunar Reconnaissance Orbiter, is one of the largest and oldest impact craters in the solar system. The Chinese Chang’e-4 lander and rover are set to explore the region after landing.
GSFC/NASA, UNIV. OF ARIZONA
The enormous impact that formed the South Pole–Aitken basin is thought to have excavated parts of the lunar mantle, the once-molten layer of denser rock that sits below the crust. Exploring the crater could offer a window into the moon’s interior.
“There’s a big argument about the composition of the lunar mantle,” Xiao says. For instance, is the mantle “wet” and full of hydrated minerals, or dry? If it is wet, how did water survive the colossal impact thought to have formed the moon? Chang’e-4 won’t solve those mysteries, but its measurements can help calibrate future remote observations.
Three cameras, an infrared spectrometer and two ground penetrating radars, like those used in the Chang’e-3 mission, will help the spacecraft conduct its investigation of Von Kármán crater. Chang’e-4 also carries some newer tech: a Swedish instrument to study how charged particles from the sun interact with the lunar surface; a German instrument to gauge radiation levels, which could be important for future astronauts; and a container with seeds and insect eggs to test whether plants and insects, if they hatch, can grow together on the moon.
Because the moon always shows the same face to Earth, astronomers on the ground won’t be able to communicate directly with Chang’e-4. So in May, the Chinese space agency launched a transmission relay satellite to a point beyond the moon to bounce data and communication signals back and forth between the lunar surface and Earth (SN Online: 5/20/18). That satellite, called Queqiao, is named after the mythical bridge of magpies that spans the Milky Way once a year to enable a tryst between two lovers.
Delving into geologic history
Sometime in 2019, the Chang’e-5 craft will visit a region on the near side of the moon that no spacecraft or astronaut has been to before. And that mission will give scientists something they haven’t had in more than four decades — new lunar rock samples.
So far, scientists have studied rocks from lava fields formed early in the moon’s history, about 3.5 billion years ago. Those were brought to Earth by the U.S. Apollo missions, which ended in 1972, and the Soviet Luna missions, ending in 1976. Together, those missions brought back more than 380 kilograms of moon material.
Chang’e-5’s lander will scoop surface rocks and dig two meters deep in a 58,000-square-kilometer area called the Rümker region that’s strewn with minerals dating to a variety of periods of volcanic activity. The craft will then bundle up to two kilograms of material into a rocket, which will launch to meet Chang’e-5’s orbiter and return to Earth.
Marking the spot
Moon rocks brought back by the Soviet Union’s Luna missions (yellow) and NASA’s Apollo missions (blue) in the 1960s and ’70s all came from ancient lava flows mostly clustered around the moon’s equator. In 2013, China’s Chang’e-3 (red square) landed in a different zone of old flows farther north, but brought back no samples. The Chang’e-5 mission will return volcanic rocks from an area that has never been sampled before (outlined in red).
USGS, NASA, Y.Q. QIAN ET AL/JOURNAL OF GEOPHYSICAL RESEARCH: PLANETS 2018, ADAPTED BY E. OTWELL
Studying samples from this region could reveal if the moon has been geologically active more recently than previously thought. “According to the study of Apollo samples, people think the moon was dead” for the last 3 billion years, Xiao says. But observations from previous orbiters suggest that Rümker includes basalt from lava flows that are less than 1.4 billion years old. “If the young mare basalt were confirmed, we would rewrite the heat history of the moon” — in other words, when the moon’s hot liquid rock cooled and hardened (SN: 8/5/17, p. 7).
Understanding the moon’s volcanic history could shed light on competing ideas about how the moon came to be. For instance, scientists still don’t agree on whether our neighbor formed from one giant impact with Earth in the early days of the solar system, around 4.5 billion years ago, or from about 20 small ones, or something else. Finding evidence for more recent geologic activity could be a ding for the single impact hypothesis.
What’s more, the returned samples would also be stored and preserved “so that future scientists who aren’t born yet can answer future questions we haven’t asked yet, with tools we haven’t invented yet,” says astrochemist Jamie Elsila of NASA’s Goddard Space Flight Center in Greenbelt, Md. She would know: Born nearly two years after the last Apollo mission, Elsila published a study in 2016 that used modern techniques to show that Apollo soil samples contain amino acids mostly derived from Earth.
Tricky access to new moon rocks
The prospect of studying those new rocks has excited NASA researchers and other scientists. Sample return is “the gift that keeps on giving,” says former Apollo astronaut Harrison “Jack” Schmitt, the only geologist to walk on the moon. “All of my colleagues who work directly with the samples certainly would like to get their hands on [those new rocks].”
But U.S. scientists face roadblocks to studying the new samples, thanks to the Wolf Amendment, a 2011 federal budget clause that requires congressional approval before U.S. scientists can collaborate with China or any Chinese-owned company.
“In terms of space science, I think with the Wolf Amendment, the United States took very careful aim and shot ourselves in the foot,” says space policy analyst Joan Johnson-Freese of the U.S. Naval War College in Newport, R.I. “We’ve made it very difficult for American scientists to work with otherwise unobtainable data.”
Difficult, but not impossible. American scientists could join scientists from other countries who can work directly with China, using their colleagues as a sort of go-between. The United States could also trade Apollo samples for Chang’e-5 samples, says space policy analyst Scott Pace, the executive secretary of the U.S. National Space Council.
“I think the U.S. and Russia would certainly be open to being part of a sample exchange process,” Pace says. “From a purely science standpoint, we’d love to have that. Whether the politics allows it, we’ll have to see.”
From China, Xiao agrees that collaboration is essential to understanding the moon’s history. “We don’t want this kind of thing to badly impact the science.”
One Chinese mission will bring back the first lunar rock samples in more than four decades
BY LISA GROSSMAN
7:00AM, NOVEMBER 11, 2018
GODDARD SPACE FLIGHT CENTER/NASA, ARIZONA STATE UNIVERSITY
China is about to make space history. In December, the country will launch the first spacecraft ever to land on the farside of the moon. Another craft, slated for takeoff in 2019, will be the first to bring lunar rocks back to Earth since 1976.
These two missions — the latest in China’s lunar exploration series named after the Chinese moon goddess, Chang’e — are at the forefront of renewed interest in exploring our nearest celestial body. India’s space agency as well as private companies based in Israel and Germany are also hoping for robotic lunar missions in 2019. And the United States aims to have astronauts orbiting the moon starting in 2023 and to land astronauts on the lunar surface in the late 2020s.
The time is ripe for new lunar exploration. Despite decades of study, Earth’s only natural satellite still contains mysteries about its formation as well as clues to the history of the solar system (SN: 4/15/17, p. 18). “There are too many things we don’t know,” says planetary scientist Long Xiao of China University of Geosciences in Wuhan. He is a coauthor of two studies published in June and July in the Journal of Geophysical Research: Planets describing the landing sites of the new Chinese missions, Chang’e-4 and -5.
To figure out what secrets the moon may still be hiding, scientists are excited to get their hands on new rock samples. The Chang’e-5 sample return mission “no doubt will have additional rock types that we haven’t sampled yet,” says planetary scientist David Blewett of Johns Hopkins University Applied Physics Laboratory in Laurel, Md. “If you came to the Earth and landed in Great Britain and made all your conclusions about the Earth from what you saw … you really wouldn’t have the whole picture.”
Journey to the dark side
The Chang’e-4 spacecraft includes a lander and a rover that were originally built as backups for the 2013 Chang’e-3 mission, which marked China’s first moon landing — and the first moon landing at all since the 1970s (SN Online: 12/16/13). The uncrewed Chang’e-3 lander-rover duo touched down in a vast lava plain in the north known as Mare Imbrium, where the craft measured the composition and thickness of the lunar soil and discovered what might be a new type of basalt, or lava-based rock.
This time, China has its sights set on lunar regions never before explored. Chang’e-4 is aiming for the moon’s largest, deepest and possibly oldest known feature created by an impact, the South Pole–Aitken basin, on the lunar farside, which always faces away from Earth. The whole basin, which is 2,500 kilometers wide and up to 8.2 kilometers deep, is too big for the rover to explore. So Chang’e-4 is shooting for the 186-kilometer-wide Von Kármán crater within the larger basin for a cosmic hole in one.
GSFC/NASA, UNIV. OF ARIZONA
The enormous impact that formed the South Pole–Aitken basin is thought to have excavated parts of the lunar mantle, the once-molten layer of denser rock that sits below the crust. Exploring the crater could offer a window into the moon’s interior.
“There’s a big argument about the composition of the lunar mantle,” Xiao says. For instance, is the mantle “wet” and full of hydrated minerals, or dry? If it is wet, how did water survive the colossal impact thought to have formed the moon? Chang’e-4 won’t solve those mysteries, but its measurements can help calibrate future remote observations.
Three cameras, an infrared spectrometer and two ground penetrating radars, like those used in the Chang’e-3 mission, will help the spacecraft conduct its investigation of Von Kármán crater. Chang’e-4 also carries some newer tech: a Swedish instrument to study how charged particles from the sun interact with the lunar surface; a German instrument to gauge radiation levels, which could be important for future astronauts; and a container with seeds and insect eggs to test whether plants and insects, if they hatch, can grow together on the moon.
Because the moon always shows the same face to Earth, astronomers on the ground won’t be able to communicate directly with Chang’e-4. So in May, the Chinese space agency launched a transmission relay satellite to a point beyond the moon to bounce data and communication signals back and forth between the lunar surface and Earth (SN Online: 5/20/18). That satellite, called Queqiao, is named after the mythical bridge of magpies that spans the Milky Way once a year to enable a tryst between two lovers.
Delving into geologic history
Sometime in 2019, the Chang’e-5 craft will visit a region on the near side of the moon that no spacecraft or astronaut has been to before. And that mission will give scientists something they haven’t had in more than four decades — new lunar rock samples.
So far, scientists have studied rocks from lava fields formed early in the moon’s history, about 3.5 billion years ago. Those were brought to Earth by the U.S. Apollo missions, which ended in 1972, and the Soviet Luna missions, ending in 1976. Together, those missions brought back more than 380 kilograms of moon material.
Chang’e-5’s lander will scoop surface rocks and dig two meters deep in a 58,000-square-kilometer area called the Rümker region that’s strewn with minerals dating to a variety of periods of volcanic activity. The craft will then bundle up to two kilograms of material into a rocket, which will launch to meet Chang’e-5’s orbiter and return to Earth.
Marking the spot
Moon rocks brought back by the Soviet Union’s Luna missions (yellow) and NASA’s Apollo missions (blue) in the 1960s and ’70s all came from ancient lava flows mostly clustered around the moon’s equator. In 2013, China’s Chang’e-3 (red square) landed in a different zone of old flows farther north, but brought back no samples. The Chang’e-5 mission will return volcanic rocks from an area that has never been sampled before (outlined in red).
Studying samples from this region could reveal if the moon has been geologically active more recently than previously thought. “According to the study of Apollo samples, people think the moon was dead” for the last 3 billion years, Xiao says. But observations from previous orbiters suggest that Rümker includes basalt from lava flows that are less than 1.4 billion years old. “If the young mare basalt were confirmed, we would rewrite the heat history of the moon” — in other words, when the moon’s hot liquid rock cooled and hardened (SN: 8/5/17, p. 7).
Understanding the moon’s volcanic history could shed light on competing ideas about how the moon came to be. For instance, scientists still don’t agree on whether our neighbor formed from one giant impact with Earth in the early days of the solar system, around 4.5 billion years ago, or from about 20 small ones, or something else. Finding evidence for more recent geologic activity could be a ding for the single impact hypothesis.
What’s more, the returned samples would also be stored and preserved “so that future scientists who aren’t born yet can answer future questions we haven’t asked yet, with tools we haven’t invented yet,” says astrochemist Jamie Elsila of NASA’s Goddard Space Flight Center in Greenbelt, Md. She would know: Born nearly two years after the last Apollo mission, Elsila published a study in 2016 that used modern techniques to show that Apollo soil samples contain amino acids mostly derived from Earth.
Tricky access to new moon rocks
The prospect of studying those new rocks has excited NASA researchers and other scientists. Sample return is “the gift that keeps on giving,” says former Apollo astronaut Harrison “Jack” Schmitt, the only geologist to walk on the moon. “All of my colleagues who work directly with the samples certainly would like to get their hands on [those new rocks].”
But U.S. scientists face roadblocks to studying the new samples, thanks to the Wolf Amendment, a 2011 federal budget clause that requires congressional approval before U.S. scientists can collaborate with China or any Chinese-owned company.
“In terms of space science, I think with the Wolf Amendment, the United States took very careful aim and shot ourselves in the foot,” says space policy analyst Joan Johnson-Freese of the U.S. Naval War College in Newport, R.I. “We’ve made it very difficult for American scientists to work with otherwise unobtainable data.”
Difficult, but not impossible. American scientists could join scientists from other countries who can work directly with China, using their colleagues as a sort of go-between. The United States could also trade Apollo samples for Chang’e-5 samples, says space policy analyst Scott Pace, the executive secretary of the U.S. National Space Council.
“I think the U.S. and Russia would certainly be open to being part of a sample exchange process,” Pace says. “From a purely science standpoint, we’d love to have that. Whether the politics allows it, we’ll have to see.”
From China, Xiao agrees that collaboration is essential to understanding the moon’s history. “We don’t want this kind of thing to badly impact the science.”
Citations
J. Huang et al. Geological characteristics of Von Kármán crater, northwestern South Pole-Aitken Basin: Chang’e-4 landing site region. Journal of Geophysical Research: Planets. Vol. 123, July 2018, p. 1684. doi:10.1029/2018JE005577.
Y.Q. Qian et al. Geology and scientific significance of the Rümker region in northern Oceanus Procellarum: China’s Chang’e-5 landing region. Journal of Geophysical Research: Planets. Vol. 123, June 2018, p. 1407. doi:10.1029/2018JE005595.
J.E. Elsila et al. The origin of amino acids in lunar regolith samples. Geochimica et Cosmochimica Acta. Vol. 172, January 2016, p. 357. doi:10.1016/j.gca.2015.10.008.
China is about to visit uncharted territory on the moon | Science NewsJ. Huang et al. Geological characteristics of Von Kármán crater, northwestern South Pole-Aitken Basin: Chang’e-4 landing site region. Journal of Geophysical Research: Planets. Vol. 123, July 2018, p. 1684. doi:10.1029/2018JE005577.
Y.Q. Qian et al. Geology and scientific significance of the Rümker region in northern Oceanus Procellarum: China’s Chang’e-5 landing region. Journal of Geophysical Research: Planets. Vol. 123, June 2018, p. 1407. doi:10.1029/2018JE005595.
J.E. Elsila et al. The origin of amino acids in lunar regolith samples. Geochimica et Cosmochimica Acta. Vol. 172, January 2016, p. 357. doi:10.1016/j.gca.2015.10.008.
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China launches Shiyan-6 and 4 micro satellites into orbit
chinadaily.com.cn | Updated: 2018-11-20 09:51
China sent Shiyan-6 satellite into space on a Long March-2D carrier rocket from Jiuquan Satellite Launch Center in Gansu province at 7:40 am on Tuesday, along with four micro satellites.
Shiyan-6 will be mainly used for detecting space environment and testing relative technologies. Two Tianping-1 micro satellites will be deployed for accuracy calibration of ground monitoring equipment.
Jiading-1 micro satellite is the first one of a low-orbit commercial communication network "Xiangyun" developed by a Shanghai-based company Space OK.
Another micro satellite is developed by the Innovation Academy for Microsatellites of CAS for carrying experiments on adopting the android system in space and the open source satellite software.
The flight is the 292nd launch of Long March series rockets.
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tass.com
Russian aviation institute to team up with China in research of Mars landing craft
2-3 minutes
© EPA/NASA/JPL-Caltech/MSSS
MOSCOW, November 21. /TASS/. The Russian Central Aero-Hydrodynamic Institute (TsAGI) will cooperate with the Chinese side in carrying out research into Mars landing craft, the TsAGI press office reported on Wednesday.
"A cooperation agreement was signed at the Airshow China 2018 on scientific and technical cooperation between TsAGI and the China Academy of Aerospace Aerodynamics and intentions were confirmed to cooperate in the research of Mars landing craft," the press office said in a statement.
Also, TsAGI and the China Aerodynamics Research and Development Center (CARDC) signed an agreement at the airshow under the project titled: "Studying the Sources of Noise of High-Drag Bodies Using Small and Large Models to Develop the Methods of Reducing the Noise of Aircraft Landing Gear."
The project is expected to be implemented as part of the federal target program "Studies and Developments in the Priority Areas of Developing the Russian Technological Complex in the Period of 2014-2020."
The 12th Airshow China 2018 international aerospace exhibition ran in Zhuhai (China) on November 6-11.
------------------------------------------------------------------------------------------
spacedaily.com
Evolving Chinese Space Ecosystem To Foster Innovative Environment
6-7 minutes
According to Euroconsult's latest report, China Space Industry 2018, the China space value chain had an estimated size of more than $16 billion in 2017, with the downstream market accounting for just over 85%. Satellite Navigation, one of the key satellite applications in China, was the main revenue generator in 2017, ahead of Satellite Communications and Earth Observation.
This premier edition of the report provides a deep-dive analysis of the current Chinese space ecosystem and future expected evolutions, from upstream to downstream, and covers each of the key satellite applications in China: Satellite Manufacturing, Launch, Satellite Communications, Earth Observation, Satellite Navigation and Space Exploration.
For each of the markets, key current and potential future players expected to have an impact on the ecosystem are profiled, including details on their strategies, funding, technological competencies and potential future plans.
"China's space industry is rapidly evolving, with an increasing number of nominally private companies competing in different parts of the space industry in both China and abroad, and with the Chinese space industry starting to play a bigger role in cutting-edge technology," said Dimitri Buchs, Senior Consultant at Euroconsult and editor of the report.
"Changes are occurring at a rapid pace across the value chain, for both upstream and downstream activities and for all application domains."
Key highlights per application domain include:
* Science and Exploration: China wants to cultivate its international leadership in space and the country has started a long-term manned space program with the Moon as a priority for space exploration and other exploration programs including a Mars mission to be confirmed. On the space science front, it has not been considered a main strategic priority area by China but the country is seeking to ramp-up its activities.
* Satellite Communications: Capacity leased by GEO satellite operators has remained largely stable in China in recent years, with demand for regular capacity dominant today. Historically the market has been dominated by China Satcom, the state-owned satellite operator, but an increasing number of Chinese companies are considering making a move into the satellite operator sphere, generally with the intention of providing services outside of China, including Huaxun Fangzhou (CCT Satcom) and Tatwah Group. Beyond this, several private constellation projects may also come to fruition (e.g. Commsat, OK Space...).
* Satellite Navigation: Given the strategic importance of satellite navigation to a variety of industries, China has for some time made it a goal of reducing its reliance on foreign navigation systems, thus the implementation of the Beidou program. The latter system is expected to achieve global coverage by 2021 with coverage of Belt and Road countries by YE 2018.
* Earth Observation: One of the most established private space industries in China, with the first nominally commercial/private Earth observation satellites having been procured in the early 2000s. Integration is continuing towards value-added services (VAS) development, even if still in the planning phase. Development of constellation fleets in both spectral and spatial resolutions is an opportunity to foster new services development. Several EO companies are quite well established (21at, Charming Globe, Space View, etc.), in parallel with several newcomers having the ability to design and operate EO satellites (Qian Sheng, etc.).
"The current changes in the space ecosystem are being brought about using different strategies, such as the opening of some markets to private enterprises and greater competition among incumbents, all of which are aimed at fostering greater innovation among companies within China," said Blaine Curcio, Senior Affiliate Consultant at Euroconsult and expert on the China commercial space market.
"Moving forward, it is expected that the Chinese government will continue to open different parts of the space industry. Indeed, with the state-owned giants more recently focusing on grander ambitions, such as China's space station, the Chang'e moon mission, and eventually human missions to the Moon and Mars, it is possible that much of what is considered traditional commercial space, and even new space, will become more open to the private sector as the state sets its sights on bigger targets."
+ China Space Industry 2018
Russian aviation institute to team up with China in research of Mars landing craft
2-3 minutes
© EPA/NASA/JPL-Caltech/MSSS
MOSCOW, November 21. /TASS/. The Russian Central Aero-Hydrodynamic Institute (TsAGI) will cooperate with the Chinese side in carrying out research into Mars landing craft, the TsAGI press office reported on Wednesday.
"A cooperation agreement was signed at the Airshow China 2018 on scientific and technical cooperation between TsAGI and the China Academy of Aerospace Aerodynamics and intentions were confirmed to cooperate in the research of Mars landing craft," the press office said in a statement.
Also, TsAGI and the China Aerodynamics Research and Development Center (CARDC) signed an agreement at the airshow under the project titled: "Studying the Sources of Noise of High-Drag Bodies Using Small and Large Models to Develop the Methods of Reducing the Noise of Aircraft Landing Gear."
The project is expected to be implemented as part of the federal target program "Studies and Developments in the Priority Areas of Developing the Russian Technological Complex in the Period of 2014-2020."
The 12th Airshow China 2018 international aerospace exhibition ran in Zhuhai (China) on November 6-11.
------------------------------------------------------------------------------------------
spacedaily.com
Evolving Chinese Space Ecosystem To Foster Innovative Environment
6-7 minutes
According to Euroconsult's latest report, China Space Industry 2018, the China space value chain had an estimated size of more than $16 billion in 2017, with the downstream market accounting for just over 85%. Satellite Navigation, one of the key satellite applications in China, was the main revenue generator in 2017, ahead of Satellite Communications and Earth Observation.
This premier edition of the report provides a deep-dive analysis of the current Chinese space ecosystem and future expected evolutions, from upstream to downstream, and covers each of the key satellite applications in China: Satellite Manufacturing, Launch, Satellite Communications, Earth Observation, Satellite Navigation and Space Exploration.
For each of the markets, key current and potential future players expected to have an impact on the ecosystem are profiled, including details on their strategies, funding, technological competencies and potential future plans.
"China's space industry is rapidly evolving, with an increasing number of nominally private companies competing in different parts of the space industry in both China and abroad, and with the Chinese space industry starting to play a bigger role in cutting-edge technology," said Dimitri Buchs, Senior Consultant at Euroconsult and editor of the report.
"Changes are occurring at a rapid pace across the value chain, for both upstream and downstream activities and for all application domains."
Key highlights per application domain include:
* Science and Exploration: China wants to cultivate its international leadership in space and the country has started a long-term manned space program with the Moon as a priority for space exploration and other exploration programs including a Mars mission to be confirmed. On the space science front, it has not been considered a main strategic priority area by China but the country is seeking to ramp-up its activities.
* Satellite Communications: Capacity leased by GEO satellite operators has remained largely stable in China in recent years, with demand for regular capacity dominant today. Historically the market has been dominated by China Satcom, the state-owned satellite operator, but an increasing number of Chinese companies are considering making a move into the satellite operator sphere, generally with the intention of providing services outside of China, including Huaxun Fangzhou (CCT Satcom) and Tatwah Group. Beyond this, several private constellation projects may also come to fruition (e.g. Commsat, OK Space...).
* Satellite Navigation: Given the strategic importance of satellite navigation to a variety of industries, China has for some time made it a goal of reducing its reliance on foreign navigation systems, thus the implementation of the Beidou program. The latter system is expected to achieve global coverage by 2021 with coverage of Belt and Road countries by YE 2018.
* Earth Observation: One of the most established private space industries in China, with the first nominally commercial/private Earth observation satellites having been procured in the early 2000s. Integration is continuing towards value-added services (VAS) development, even if still in the planning phase. Development of constellation fleets in both spectral and spatial resolutions is an opportunity to foster new services development. Several EO companies are quite well established (21at, Charming Globe, Space View, etc.), in parallel with several newcomers having the ability to design and operate EO satellites (Qian Sheng, etc.).
"The current changes in the space ecosystem are being brought about using different strategies, such as the opening of some markets to private enterprises and greater competition among incumbents, all of which are aimed at fostering greater innovation among companies within China," said Blaine Curcio, Senior Affiliate Consultant at Euroconsult and expert on the China commercial space market.
"Moving forward, it is expected that the Chinese government will continue to open different parts of the space industry. Indeed, with the state-owned giants more recently focusing on grander ambitions, such as China's space station, the Chang'e moon mission, and eventually human missions to the Moon and Mars, it is possible that much of what is considered traditional commercial space, and even new space, will become more open to the private sector as the state sets its sights on bigger targets."
+ China Space Industry 2018
JSCh
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China, Brazil to launch new Earth resource satellite next year
Source: Xinhua| 2018-11-22 20:13:24|Editor: Liangyu
BEIJING, Nov. 22 (Xinhua) -- China and Brazil will launch a new Earth resource satellite next year, according to an official with the China National Space Administration.
NEW SATELLITE
"The new satellite, the China-Brazil Earth Resource Satellite-4A, or CBERS-4A, will be launched in the second half of 2019," said Li Guoping, the secretary-general of the China National Space Administration, in a recent interview with Xinhua prior to a symposium held in Beijing Thursday, in commemoration of the 30th anniversary of China-Brazil space cooperation.
The CBERS satellites are Earth remote sensing satellites, specifically designed for Earth observation from orbit for non-military use, such as environment monitoring, meteorology and map making.
According to Li, CBERS-4A, the new satellite to be launched, is assembled and currently going through tests in Brazil. It is set to replace CBERS-4. CBERS-4, launched in December 2014, is currently in great condition although under extended service.
"The two countries will also start the final design and research of CBERS-5 and CBERS-6. The two satellites will be successors to CBERS-4A, which is designed to serve for five years," Li said.
China and Brazil inked the agreement establishing the joint research and production of the CBERS series in July 1988. The program has set a good example for cooperation among developing countries in the field of space technology, and has been praised as a model of "South-South cooperation."
OLD FRIENDS
In July 1988, China and Brazil inked the agreement establishing the joint research and production of the CBERS.
CBERS-1, the first satellite in the program was successfully launched in October 1999, giving each country their first transmission-type remote sensing satellite. It was rated one of the top 10 scientific and technological advances of the year in China.
It was the first satellite jointly developed by China and another country, and set a good example for cooperation among developing countries in the field of space technology, and was praised as a model of "South-South cooperation."
Meanwhile, data from the CBERS satellites, according to Li, are provided to a number of Asia-Pacific and Latin American countries for free.
FUTURE COOPERATION
"I think the cooperation between China and Brazil in space will last more than that. I hope it will last more than 100 years," said Jose Raimundo Coelho, president of the Brazilian Space Agency in an interview.
Both Raimundo and Li said that the two countries would continue to work together in order to consolidate and expand cooperation beyond the CBERS program.
In 2016, the space agencies of BRICS states announced plans to create a joint satellite constellation for Earth remote sensing. BRICS groups Brazil, Russia, India, China and South Africa.
Each country will provide one to two satellites to the constellation, and the project will mainly provide service to developing countries, according to Li.
The CBERS satellites would be included in the constellation program.
"Our satellites have to be useful for the humankind. I believe the CBERS brand will have its role enhanced worldwide. Even more than it already is," Raimundo said.
Source: Xinhua| 2018-11-22 20:13:24|Editor: Liangyu
BEIJING, Nov. 22 (Xinhua) -- China and Brazil will launch a new Earth resource satellite next year, according to an official with the China National Space Administration.
NEW SATELLITE
"The new satellite, the China-Brazil Earth Resource Satellite-4A, or CBERS-4A, will be launched in the second half of 2019," said Li Guoping, the secretary-general of the China National Space Administration, in a recent interview with Xinhua prior to a symposium held in Beijing Thursday, in commemoration of the 30th anniversary of China-Brazil space cooperation.
The CBERS satellites are Earth remote sensing satellites, specifically designed for Earth observation from orbit for non-military use, such as environment monitoring, meteorology and map making.
According to Li, CBERS-4A, the new satellite to be launched, is assembled and currently going through tests in Brazil. It is set to replace CBERS-4. CBERS-4, launched in December 2014, is currently in great condition although under extended service.
"The two countries will also start the final design and research of CBERS-5 and CBERS-6. The two satellites will be successors to CBERS-4A, which is designed to serve for five years," Li said.
China and Brazil inked the agreement establishing the joint research and production of the CBERS series in July 1988. The program has set a good example for cooperation among developing countries in the field of space technology, and has been praised as a model of "South-South cooperation."
OLD FRIENDS
In July 1988, China and Brazil inked the agreement establishing the joint research and production of the CBERS.
CBERS-1, the first satellite in the program was successfully launched in October 1999, giving each country their first transmission-type remote sensing satellite. It was rated one of the top 10 scientific and technological advances of the year in China.
It was the first satellite jointly developed by China and another country, and set a good example for cooperation among developing countries in the field of space technology, and was praised as a model of "South-South cooperation."
Meanwhile, data from the CBERS satellites, according to Li, are provided to a number of Asia-Pacific and Latin American countries for free.
FUTURE COOPERATION
"I think the cooperation between China and Brazil in space will last more than that. I hope it will last more than 100 years," said Jose Raimundo Coelho, president of the Brazilian Space Agency in an interview.
Both Raimundo and Li said that the two countries would continue to work together in order to consolidate and expand cooperation beyond the CBERS program.
In 2016, the space agencies of BRICS states announced plans to create a joint satellite constellation for Earth remote sensing. BRICS groups Brazil, Russia, India, China and South Africa.
Each country will provide one to two satellites to the constellation, and the project will mainly provide service to developing countries, according to Li.
The CBERS satellites would be included in the constellation program.
"Our satellites have to be useful for the humankind. I believe the CBERS brand will have its role enhanced worldwide. Even more than it already is," Raimundo said.
JSCh
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- Jun 9, 2011
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China successfully tests recovering 7-ton spacecraft
chinadaily.com.cn | Updated: 2018-11-23 10:50
Shenzhou XI return capsule touches down in Inner Mongolia on Nov 18, 2016. [Photo/Xinhua]
Chinese researchers have successfully tested two major systems in recovering large spacecraft of more than 7 tons, a weight of US Orion spacecraft, and the breakthrough improves China's capability to reach the world leading level.
In the past, China's Shenzhou spacecrafts were around 3.5 tons and the recovery system included a single main parachute system and a back propulsion engine that could only be used once.
Recently, researchers from China Academy of Space Technology used a helicopter to drop the 7-ton model in testing the country's large parachute group system and heavy load landing buffer system (airbag system).
The parachute group system includes two deceleration parachutes for reducing speed in the early stage of reentry and three main parachutes. The deceleration parachutes are brand-new products. Researchers optimized the design of main parachutes to ensure the synchronization of inflation.
The airbag system includes multiple bags and researchers have achieved breakthroughs in the structure design and the active exhaust control technologies to keep the spacecraft's stability in landing.
The landing is in a very short time, and therefore, researchers have to use the most sensitive detectors to make the buffer system to make quick response under control. The airbag system could be reused.
The breakthroughs in recovery technologies could be used in rocket recovery and heavy equipment airdrop, and are very important for the country to go ahead on the manned lunar mission and pave way for recovering loads of 15 tons.
chinadaily.com.cn | Updated: 2018-11-23 10:50
Shenzhou XI return capsule touches down in Inner Mongolia on Nov 18, 2016. [Photo/Xinhua]
Chinese researchers have successfully tested two major systems in recovering large spacecraft of more than 7 tons, a weight of US Orion spacecraft, and the breakthrough improves China's capability to reach the world leading level.
In the past, China's Shenzhou spacecrafts were around 3.5 tons and the recovery system included a single main parachute system and a back propulsion engine that could only be used once.
Recently, researchers from China Academy of Space Technology used a helicopter to drop the 7-ton model in testing the country's large parachute group system and heavy load landing buffer system (airbag system).
The parachute group system includes two deceleration parachutes for reducing speed in the early stage of reentry and three main parachutes. The deceleration parachutes are brand-new products. Researchers optimized the design of main parachutes to ensure the synchronization of inflation.
The airbag system includes multiple bags and researchers have achieved breakthroughs in the structure design and the active exhaust control technologies to keep the spacecraft's stability in landing.
The landing is in a very short time, and therefore, researchers have to use the most sensitive detectors to make the buffer system to make quick response under control. The airbag system could be reused.
The breakthroughs in recovery technologies could be used in rocket recovery and heavy equipment airdrop, and are very important for the country to go ahead on the manned lunar mission and pave way for recovering loads of 15 tons.
JSCh
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21 Nov 2018 | 20:00 GMT
China Gears Up for Ambitious Landing on the Moon’s Far Side
The biggest problem is how to talk to a rover whose radio will be hidden from the Earth
By Andrew Jones
Image: Xinhua/Alamy
Touchdown: Humans will steer China’s Chang’e-4 lander through the first half of its descent to the moon’s surface. Then, the spacecraft will complete its landing autonomously.
In December, China will attempt the first soft landing of a spacecraft on the far side of the moon. No official date has been announced, but the mission is rumored for launch around 8 December, with a landing to follow late in the month.
Mission scientists say the capability to precisely land on a specific spot on the moon and conduct autonomous exploration from there will lay a foundation for future lunar and deep-space exploration, including expanded missions to the lunar poles in the early 2020s. But their ambitious effort requires new and improved communications, navigation, and landing technologies.
The Chang’e-4 lander and rover, which could soon become the first spacecraft to touch the moon’s far side, were originally designed as backups for the Chang’e-3 mission, which in 2013 completed China’s first moon landing. After Chang’e-3 successfully touched down on Mare Imbrium, a lava field on the lunar near side, the Chang’e-4 spacecraft were repurposed for a far-side landing.
Notably, the Chang’e-3 rover, called Yutu, or Jade Rabbit, permanently lost its ability to rove after moving only 114 meters in its first two lunar days (about a month, in Earth time). Li Ming, vice president of the China Academy of Space Technology, said in October at the International Astronautical Congress, in Germany—without revealing technical details—that the problem was related to very small components. The new 140-kilogram Chang’e-4 rover, he added, should prove more reliable and function longer than even the three months that Yutu should’ve lasted by design.
Images, top: China Academy of Space Technology; Bottom: Reuters
Far From Home: The Queqiao satellite [top, orange] follows an orbit [green] that places it just past the moon [gray]. From there, it can relay information from China’s new rover [bottom] to Earth and back.
The first challenge for the Chang’e-4 team was that the far side of the moon cannot be seen directly from Earth. Over time, Earth’s gravitational pull has slowed the moon’s rotation to match its orbital period, with the result that one side of the moon always faces Earth. Unfortunately, not having a clear view of the moon’s other side makes it difficult for earthlings to send and receive signals with a rover placed there.
To overcome this, China launched a communications relay satellite in May named Queqiao, which passed beyond the moon and inserted itself into what is known as a Lissajous orbit. In this orbit, the satellite will revolve around a point about 60,000 to 80,000 kilometers beyond the moon (also known as the second Earth-moon Lagrange point), as it follows the moon’s path around Earth. From there, it will always keep both the lunar far side and Earth within sight.
If all goes as planned, Queqiao will use the long-range radio-frequency X-band to communicate with both the lander and rover, while the latter two will speak to each other via ultrahigh-frequency radios. China’s ground stations and Queqiao will use the S-band to send data back and forth. China has recently expanded the range of its ground stations by adding sites in Argentina and Namibia to those at Jiamusi and Kashi in China, to provide telemetry, tracking, and command for spacecraft.
When it comes to landing the combined 3,780-kg spacecraft, the topography of the lunar far side is also quite different from that of the near side. The surface on the far side is very rugged, with few of the flat maria—dark, basaltic plains—abundant on the near side. The far side also features more variability in surface altitude and much greater crater coverage. All of this makes it difficult to find a large, flat landing spot, meaning the candidate landing sites will be reduced from areas covering hundreds of square kilometers for Chang’e-3 down to tens of square kilometers for Chang’e-4.
Due to these constraints, Chang’e-4 will target the 180-km-diameter Von Kármán crater within the South Pole–Aitken basin. That area is the oldest impact basin in the solar system and of great interest to scientists because it could contain exposed areas of the lunar mantle and provide clues to the evolution of the Earth-moon system. Crucially for the landing, the Von Kármán crater is flatter than any other spot in the South Pole–Aitken basin, says Ping Jinsong, principal investigator for the low-frequency spectrometer on the lander.
Photo: Reuters
Moon Mission: This snapshot of the Chang’e-3 lander was taken by the rover that accompanied it to the moon in 2013.
Algorithms used by the Chang’e-4 guidance, navigation, and control subsystem—which will guide the lander’s movements, determine its position, and plan its course—have been altered to prevent the undulating far-side topography from adversely influencing the landing, as it would have for Chang’e-3.
The spacecraft will descend in six phases. The first three—initial deceleration, quick attitude and reorientation adjustment, and approach—will be controlled remotely. The final three—hovering, hazard avoidance, and slow descent—will be carried out autonomously by the lander. During descent, the spacecraft will cover around 450 km, but the oblique forward trajectory of the Chang’e-3 descent will be replaced with a much more vertical, downward trajectory for Chang’e-4.
The lander and rover have also been adapted for their new roles on the moon’s surface. They each incorporate a power supply based on radioisotope thermoelectric generators that will allow them to measure soil temperatures—for example, during the lunar night when the surface temperature drops to nearly –180 °C. With all such preparations in place, Chang’e-4 is finally ready to break new ground on the moon, and share its findings with its architects on Earth.
China Gears Up for Ambitious Landing on the Moon’s Far Side - IEEE Spectrum
China Gears Up for Ambitious Landing on the Moon’s Far Side
The biggest problem is how to talk to a rover whose radio will be hidden from the Earth
By Andrew Jones
Touchdown: Humans will steer China’s Chang’e-4 lander through the first half of its descent to the moon’s surface. Then, the spacecraft will complete its landing autonomously.
In December, China will attempt the first soft landing of a spacecraft on the far side of the moon. No official date has been announced, but the mission is rumored for launch around 8 December, with a landing to follow late in the month.
Mission scientists say the capability to precisely land on a specific spot on the moon and conduct autonomous exploration from there will lay a foundation for future lunar and deep-space exploration, including expanded missions to the lunar poles in the early 2020s. But their ambitious effort requires new and improved communications, navigation, and landing technologies.
The Chang’e-4 lander and rover, which could soon become the first spacecraft to touch the moon’s far side, were originally designed as backups for the Chang’e-3 mission, which in 2013 completed China’s first moon landing. After Chang’e-3 successfully touched down on Mare Imbrium, a lava field on the lunar near side, the Chang’e-4 spacecraft were repurposed for a far-side landing.
Notably, the Chang’e-3 rover, called Yutu, or Jade Rabbit, permanently lost its ability to rove after moving only 114 meters in its first two lunar days (about a month, in Earth time). Li Ming, vice president of the China Academy of Space Technology, said in October at the International Astronautical Congress, in Germany—without revealing technical details—that the problem was related to very small components. The new 140-kilogram Chang’e-4 rover, he added, should prove more reliable and function longer than even the three months that Yutu should’ve lasted by design.
Far From Home: The Queqiao satellite [top, orange] follows an orbit [green] that places it just past the moon [gray]. From there, it can relay information from China’s new rover [bottom] to Earth and back.
The first challenge for the Chang’e-4 team was that the far side of the moon cannot be seen directly from Earth. Over time, Earth’s gravitational pull has slowed the moon’s rotation to match its orbital period, with the result that one side of the moon always faces Earth. Unfortunately, not having a clear view of the moon’s other side makes it difficult for earthlings to send and receive signals with a rover placed there.
To overcome this, China launched a communications relay satellite in May named Queqiao, which passed beyond the moon and inserted itself into what is known as a Lissajous orbit. In this orbit, the satellite will revolve around a point about 60,000 to 80,000 kilometers beyond the moon (also known as the second Earth-moon Lagrange point), as it follows the moon’s path around Earth. From there, it will always keep both the lunar far side and Earth within sight.
If all goes as planned, Queqiao will use the long-range radio-frequency X-band to communicate with both the lander and rover, while the latter two will speak to each other via ultrahigh-frequency radios. China’s ground stations and Queqiao will use the S-band to send data back and forth. China has recently expanded the range of its ground stations by adding sites in Argentina and Namibia to those at Jiamusi and Kashi in China, to provide telemetry, tracking, and command for spacecraft.
When it comes to landing the combined 3,780-kg spacecraft, the topography of the lunar far side is also quite different from that of the near side. The surface on the far side is very rugged, with few of the flat maria—dark, basaltic plains—abundant on the near side. The far side also features more variability in surface altitude and much greater crater coverage. All of this makes it difficult to find a large, flat landing spot, meaning the candidate landing sites will be reduced from areas covering hundreds of square kilometers for Chang’e-3 down to tens of square kilometers for Chang’e-4.
Due to these constraints, Chang’e-4 will target the 180-km-diameter Von Kármán crater within the South Pole–Aitken basin. That area is the oldest impact basin in the solar system and of great interest to scientists because it could contain exposed areas of the lunar mantle and provide clues to the evolution of the Earth-moon system. Crucially for the landing, the Von Kármán crater is flatter than any other spot in the South Pole–Aitken basin, says Ping Jinsong, principal investigator for the low-frequency spectrometer on the lander.
Moon Mission: This snapshot of the Chang’e-3 lander was taken by the rover that accompanied it to the moon in 2013.
Algorithms used by the Chang’e-4 guidance, navigation, and control subsystem—which will guide the lander’s movements, determine its position, and plan its course—have been altered to prevent the undulating far-side topography from adversely influencing the landing, as it would have for Chang’e-3.
The spacecraft will descend in six phases. The first three—initial deceleration, quick attitude and reorientation adjustment, and approach—will be controlled remotely. The final three—hovering, hazard avoidance, and slow descent—will be carried out autonomously by the lander. During descent, the spacecraft will cover around 450 km, but the oblique forward trajectory of the Chang’e-3 descent will be replaced with a much more vertical, downward trajectory for Chang’e-4.
The lander and rover have also been adapted for their new roles on the moon’s surface. They each incorporate a power supply based on radioisotope thermoelectric generators that will allow them to measure soil temperatures—for example, during the lunar night when the surface temperature drops to nearly –180 °C. With all such preparations in place, Chang’e-4 is finally ready to break new ground on the moon, and share its findings with its architects on Earth.
China Gears Up for Ambitious Landing on the Moon’s Far Side - IEEE Spectrum
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