China Outer Space Science, Technology and Explorations: News & Updates

[JSCh]

China's state-of-the-art satellites great assets for global meteorological service: WMO head
Source: Xinhua| 2019-06-14 06:20:06|Editor: Mu Xuequan

GENEVA, June 13 (Xinhua) -- China's state-of-the-art meteorological service system and Fengyun satellites are great assets for enhancing global meteorological capability, especially for island and African countries, the head of the World Meteorological Organization (WMO) said Thursday.

Speaking during the 18th World Meteorological Congress (WMC) in Geneva, Switzerland, WMO Secretary-General Petteri Taalas highly valued China's contribution in helping deliver and enhance global meteorological service under the framework of the "Belt and Road Initiative(BRI)."

China has been helping train plenty of meteorological experts at its Nanjing University, when there has been a great need for such experts worldwide, especially in African countries, Talaas said. He also thanked China for supporting many African countries in building their meteorological infrastructure and service capacity, as well as providing meteorological satellite information and program to other WMO members.

Talaas' remarks came at a promotion of international service by China's Fengyun meteorological satellites during the WMC, where the WMO and China are expected to hold a meeting to further push ahead their meteorological cooperation under the BRI framework.

According to Liu Yaming, administrator of China Meteorological Administration, FengYu meteorological satellites providing international service is a very important part of the meteorological cooperation between China and countries along the Belt and Road. It has helped build the capability of these countries in acquiring and applying satellite data, and in turn forecasting meteorological disasters as well as disaster alleviation.

According to the China National Space Administration, China already has 17 Fengyun series meteorological satellites in space, with eight in operation, including five in geostationary orbit and three in polar orbit to observe extreme weather, climate and environment events around the globe.

The Fengyun series meteorological satellites provide data to clients in more than 80 countries and regions. Weather forecasts in the eastern hemisphere mainly depend on China's meteorological satellites.

 

[JSCh]

UN space chief hails broad, in-depth cooperation with China
Source: Xinhua | 2019-06-15 20:36:40 | Editor: huaxia

Simonetta Di Pippo (R), Director of the United Nations Office for Outer Space Affairs, visits the Chinese navigation exhibition "From Compass to BeiDou" in Vienna, Austria, on June 11, 2019. (Xinhua/Guo Chen)

VIENNA, June 15 (Xinhua) -- Simonetta Di Pippo, Director of the United Nations Office for Outer Space Affairs, has hailed China's accomplishment in space as well as the country's close cooperation with the UN office.

The 62nd session of the Committee on the Peaceful Uses of Outer Space is ongoing here in Vienna, from June 12 to 21.

A Chinese navigation exhibition and the announcement of which international scientific experiments would fly with the China Space Station (CSS) took place in close proximity -- in both timing and location -- to the session. And on the sidelines, Di Pippo told Xinhua this week "we are waiting for the Chinese space station to become a reality."

Before the CSS becomes operational, expected around 2022, China has been engaging in a series of space explorations.

"One of the most recent accomplishments for sure is the launch and landing of Chang'e-4 on the far side to the moon just in January this year," Di Pippo said. "But also it's the beginning of a long set of missions exploring moon and the other planets."

China's Chang'e-4 probe, launched on Dec. 8, 2018, made the first-ever soft landing on the Von Karman Crater in the South Pole-Aitken Basin on the far side of the moon on Jan. 3.

Also, China's Beidou Navigation Satellite System (BDS) is now "a real pillar in this architecture" of global navigation satellite systems, the UN space chief said.

China began to construct the BDS, named after the Chinese term for the Big Dipper constellation, in the 1990s. It started serving China with its BDS-1 system in 2000 and started serving the Asia-Pacific region with its BDS-2 system in 2012. China will complete the BDS global network by 2020.

"Together with Beidou, we bring up the same table the Russian Federation with GLONASS, the Europeans with Galileo and the Americans with GPS, plus others which are preparing...to launch their own systems," she said.

These systems are not in a war with each other, the UN space chief said, as there is a mechanism called ICG (International Committee on Global Navigation Satellite Systems), which is "a sort of a role model in terms of international cooperation, because we put together all the providers and in this way we can increase precision".

"We can add a higher number of satellites and coverage so the signal is more precise and more stable", which she said would allow the signals to be "used by everyone in the world".

As the UN space chief, the trained Italian astrophysicist is big on international cooperation, and appreciates Chinese emphasis in this area.

In cooperating with the China Manned Space Agency in opening the CSS to international scientific experiments from all UN member states, she said it's "the first time that something like that has been done".

"We have other agreements with other space agencies and other entities to do similar things, but not so broad as in the case of the CSS," Di Pippo said.

"In the previous activities we did with other entities including JAXA for example, or the European Space Agency, we were talking about...in any case small experiments. Here in this case obviously the technical implications are far more serious," she said.

"We have also a lot of other agreements and discussions ongoing with different Chinese organizations," she added.

 

[JSCh]

NEWS * 17 JUNE 2019
China reveals scientific experiments for its next space station | Nature
Projects will probe topics including DNA mutation, fire behaviour and the birth of stars.

Elizabeth Gibney

Chinese astronauts are scheduled to have their own major space station from 2022.Credit: Chen Bin/Xinhua/Zuma

China has selected nine scientific experiments — including a project that will probe how DNA mutates in space — to fly on its first major space station, scheduled to be completed in 2022.

The China Manned Space Agency selected the projects, which involve scientists from 17 nations, from 42 hopefuls, in a process organized with the United Nations Office for Outer Space Affairs (UNOOSA).

China’s existing space laboratory, Tiangong-2, which launched in 2016, also hosts experiments, but the new space station will be bigger and is intended to last longer. Known as the China Space Station, the outpost will be less than one-quarter of the mass of the International Space Station (ISS).

The science projects cover similar topics to experiments that have flown on the ISS since its launch in 1998, including fluid and fire behaviour, biology and astronomy.

Scientists working on the projects hail from spacefaring nations such as Russia, Japan and India, as well as low- and middle-income countries including Kenya, Mexico and Peru — the result of a special effort to encourage participation from such nations. “The cooperation takes into account the special needs of developing countries, which were encouraged to submit joint project applications with developed countries,” said Wang Qun, China’s ambassador to the United Nations in Vienna, in a statement.

The experiments include an Indian–Russian observatory called Spectroscopic Investigations of Nebular Gas, which will map dust clouds and star-forming regions of space using ultraviolet light. A group of European institutions, meanwhile, will study how microgravity and radiation in space affect the mutation of DNA in human ‘organoids’ — 3D biological structures that mimic organs. And a Saudi Arabian team will test how solar cells perform on the outside of the space station.

Other winners include a detector called POLAR-2, a more powerful follow-up to a sensor launched on Tiangong-2 to study the polarization of energetic γ-ray bursts from distant cosmic phenomena. POLAR-2, which will be built by an international collaboration, could even allow astronomers to observe the weak radiation associated with sources of gravitational waves.

But none of the experiments come from the United States, which since 2011 has forbidden NASA researchers from collaborating with China without congressional approval. A spokesperson for UNOOSA told Nature that US scientists were eligible to take part and were involved in several applications, but those projects weren’t ultimately selected.

The United States is planning to cut its funding for the ISS from 2024, as it concentrates its space efforts on building an outpost in the Moon’s orbit from 2022. This could mean that the Chinese space station becomes scientists’ only laboratory in low Earth orbit from 2024.

 

[JSCh]

China looks to space in its fight against desert expansion
2019-06-18 13:58:11 CGTN

Zanthoxylum bungeanum Maxim. or Sichuan peppers. (Photo/CGTN)

Just an hour's drive south from downtown Xi'an lies an extraordinary farmland. At first glance, its crops, flowers, and saplings seem ordinary. Only the informed would know that these seeds were nurtured in space.

Guo Rui, director of Yangling Seeds Corporation, leads a state-funded space breeding center founded in August 2018 in China's northwestern province of Shaanxi. The center's mission is to cultivate high-quality crop and tree seeds to curb the expansion of the Gobi Desert.

"Within the next three to five years, we plan to cultivate 22 crop and tree species for the Three-North Shelter Forest Program," Guo told CGTN. Also known as the "Green Great Wall," the program aims to build a 4,500-kilometer-long forest belt along the northern parts of China by 2050. The next satellite, carrying seeds into orbit, is set to be launched within a year.

Extraterrestrial conditions such as high radiation, low temperature, and zero gravity enable the production of seed variations that are superior in both quality and output, Guo explained.

Space breeding involves sending seeds attached to a satellite into orbit for a few days. Then upon their return to Earth, mutated seeds are selected, based on favorable genetic traits, ranging from resistance to extreme weather to extra nutrients, and planted.

"The cultivation period of such high-quality seeds is reduced from eight years to four years," Guo added.

Space breeding, however, is costly. Each launch of a satellite amounts to hundreds of millions of yuan. Accordingly, while trying to lower the cost itself, Chinese scientists are also striving to better understand the mutations that occur in space.

"By figuring out how seeds mutate and result in superior qualities, we hope to create ground-based simulations of the extraterrestrial environment," explained Professor Wen Xianfang of the Chinese Academy of Agricultural Sciences.

In the past three decades, more than 6,000 seeds have been sent into space, resulting in some 230 species ranging from crops to Chinese medicinal herbs. Recent breeds include "Zanthoxylum bungeanum Maxim." – more simply known as Sichuan pepper – which are more resistant to pests and shorter in height, making them easier for harvesting. By next year, the peppers will be ready for public consumption.

For China's interplanetary initiatives designed to ensure both food and land security, the sky could literally be the limit.

 

[JSCh]

Chinese astronomers to search for cradles of new suns with FAST
Source: Xinhua| 2019-06-23 18:24:43|Editor: mingmei

BEIJING, June 23 (Xinhua) -- How many new suns could emerge in the Milky Way in the future?

Chinese astronomers plan to use the Five-hundred-meter Aperture Spherical Radio Telescope (FAST), by far the largest telescope ever built, to search for birthplaces of new suns so they can better understand how stars and life substances are formed.

Astronomers at the National Astronomical Observatories of the Chinese Academy of Sciences recently caught the birth of a dark molecular cloud for the first time by using three telescopes of the United States and Europe.

The discovery was published in the Astrophysical Journal, and introduced by the journal Nature as a research highlight.

Scientists found dark regions in the universe that are rich in atomic and molecular gases and cosmic dust, known as interstellar dark clouds, which are the birthplaces of new stars, new planets, and possibly life.

The discovery made Li Di, chief scientist of FAST, very confident of finding the birthplaces of new suns with FAST in the future.

"The high sensitivity of FAST and its advantage in sky coverage will enable us to study the molecular clouds in the Milky Way, as well as in the Andromeda Galaxy, adjacent to our galaxy," Li said.

"We also plan to cooperate with the Milky Way Image Scroll Project of the Purple Mountain Observatory to catch the dark clouds at birth, and to study how many new suns will be born in our galaxy," said Li.

 

[JSCh]

China’s moon, Mars and space station missions may be facing delays
by Andrew Jones — June 21, 2019

A Long March 5 rocket lifts off from the Wenchang Satellite Launch Center July 2. The launch was later declared a failure. Credit: Xinhua

HELSINKI — China’s major space missions including a lunar sample return, Mars orbiter and rover and a modular space station could be facing delays due to an apparent issue affecting rockets required for launches.

The Long March 5 heavy-lift rocket is China’s most powerful launch vehicle and was designed to launch large spacecraft to geosynchronous orbits and planetary bodies. It was being prepared for a third flight in July, Yang Baohua, vice president of the China Aerospace Science and Technology Corporation (CASC), China’s main space contractor and developer of the Long March 5, announced in a Jan. 29 news conference in Beijing.

The mission would come two years after the failure of the second launch. However that schedule appears to have slipped as the launch vehicle has yet to be delivered to the launch site, with knock-on effects possible for China’s major space plans.

The fourth Long March 5 was expected send the Chang’e-5 lunar sample return mission into trans-lunar injection at the end of 2019. The fifth launch was slated to launch the country’s first independent mission to Mars during a once-every-26-month launch window in late July to early August 2020.

In between, a test launch necessary for the construction of the future Chinese Space Station was due to take place.

The last reports on the Long March 5 from Chinese media appeared in April, showing components of the rocket apparently ready for transport, in time for the scheduled launch.

Components of the Long March 5 are manufactured in the northern port city of Tianjin, and are collected by two specially designed cargo ships, Yuanwang-21 and Yuanwang-22, then delivered to the Wenchang Satellite Launch Center on the southern island of Hainan.

That process takes around two-and-a-half weeks, after which launch preparations at the launch complex for the first two Long March 5 rockets took two months.

However the transportation of components has not taken place and, according to open source ship tracking, both ships have remained moored at Jiangyin since early April since the completion of refurbishment. This is backed up by the latest available imagery from the European Space Agency’s Sentinel 2B Earth observation satellite showing the two 100-meter-long ships moored on June 3.

Yuanwang-21 and 22 (circled) moored at Jiangyin June 3. Credit: Andrew Jones/EU, modified Copernicus Sentinel Data 2019, processed with EO Browser.

There has been no official or media update on the status of the planned July mission. This correspondent has been informed by figures close to the Chinese aerospace industry that online discussion of the matter has been discouraged and could deleted by China’s internet censorship apparatus.

The Long March 5 was not among other Long March series launch vehicle models showcased at the ongoing Paris Airshow by the China Great Wall Industry Corp., a CASC subsidiary.

Should activities indicating preparations for launch begin immediately, the Long March 5 would be ready for flight no earlier than September. The longer the rocket is grounded, the greater the pressure on a busy launch schedule.

While the Chang’e-5 mission will have regular opportunities for flight, if the 2020 Mars launch window is missed there will not be another opportunity to launch until late 2022, due to the respective orbits of Earth and Mars.

The Long March 5 had a successful first flight in late 2016 but suffered a failure in early July 2017. An investigation identified the problem to be a fault with the turbopump on the YF-77 cryogenic engines which power the rocket’s first stage.

Following successful ground test firing of redesigned YF-77 engines in February 2018, a return-to-flight of the Long March 5 was slated for later that year. When this slipped, the new July target was issued in early 2019.

When it does launch, the third Long March 5 will carry the Shijian-20 (“Practice-20”) communications satellite, based on a new, large DFH-5 satellite platform which supports satellites from 6,500 to 9,000 kilograms.

Space station delay possible

A variant of this rocket, the Long March 5B, is also being developed to facilitate the launch of 20-metric-ton space station modules to low Earth orbit. As it uses the same engines and similar cores, its test flight is dependent on a successful return-to-flight of the Long March 5.

The Long March 5B test flight was planned for the first half of next year, carrying an uncrewed next-generation spacecraft, opening the possibility for the launch of the core module of the Chinese Space Station later in 2020.

A joint June 12 announcement by the United Nations Office for Outer Space Affairs (UNOOSA) and the China Manned Space Agency (CMSA) revealed that nine international experiments had been selected for a place aboard the CSS, maintaining that the target for completion of the three-module complex remains to be ‘around 2022’.

The ‘Tianhe’ core module was expected to launch in 2018, before the failure of the second Long March 5 in 2017 delayed the Long March 5B test launch and the Chang’e-5 Moon mission, which had been scheduled for December 2017.

In 2014, China laid out plans to launch the three 20-metric ton modules which will make up the orbital outpost in 2018, 2020 and 2022. That schedule will at best be condensed.



China’s moon, Mars and space station missions may be facing delays - SpaceNews.com

 

[JSCh]

JUNE 26, 2019 REPORT
Highest energy photons ever recorded coming from Crab Nebula
by Bob Yirka , Phys.org

The Crab Nebula. Credit: NASA

A very large team of researchers affiliated with several institutions in China and Japan has measured the highest energy photon ever recorded. In their paper published in the journal Physical Review Letters, the group describes their study of data from the Tibet Air Shower Gamma Collaboration and what they found.

The Tibet Air Shower Gamma Collaboration is an observatory in the Tibetan Plateau and the people that run it. It consists of 600 particle detectors built on a 65,000-square-meter parcel of land. Its objective is to detect subatomic particles emanating from space. The detectors there observe the debris from photons colliding with particles in the Earth's atmosphere and cosmic rays, which are mostly protons and atomic nuclei. The team members with this new effort were focused on photons that make their way to Earth from far-off places. To measure them, the researchers excluded muon detections, leaving only particles associated with photon collisions. The researchers were able to calculate the energy of a given photon using data from the particles that it struck.

The researchers report that they found what they believe to be 24 photon-initiated showers, with photon energies above 100 trillion electron volts—one of which registered 450 TeV. These finds represent the first measurements of high energy photons over 100 TeV and the highest ever recorded.

The researchers also used the data from the collaboration to track the paths of the photons, and found they originated in the Crab Nebula, the remains of a supernova that exploded in 1054 AD. The Crab Nebula is located in the Perseus Arm of the Milky Way, approximately 6,500 light years away.

The research team has been studying high-energy photons that make their way to Earth as part of an effort to understand why they have so much energy. Current theory suggests that the photons get their energy from other high-energy particles via inverse Compton scattering, in which photons absorb the energy of high-energy particles when they collide, for example, during supernovae. The photons themselves are believed to have been created by processes involved in the Big Bang.


https://phys.org/news/2019-06-highest-energy-photons-crab-nebula.html

 

[JSCh]

ADASpace set to star in AI satellite constellation sphere
By Wang Yi Source:Global Times Published: 2019/6/30 19:33:41

Visitors look at the Beidou navigation satellite constellation during a science show in March. Photo: VCG

A private Chinese company plans to build the country's first artificial intelligence (AI) satellite constellation, which will have stronger autonomous operating capacity and improve efficiency in applications including natural disaster responses.

To evaluate how existing telecom standards and AI solutions can be leveraged to manage future satellite constellations is a positive attempt. This ambitious plan by a private company shows how China's aerospace industry is thriving, according to analysts.

ADASpace, based in Chengdu, capital of Southwest China's Sichuan Province, specializes in satellite design and data services. It signed a strategic agreement on Saturday with a launch vehicle producer for its Xingshidai plan, which aims to build an AI constellation by 2021.

The first AI constellation will consist of 192 satellites equipped with AI systems. This constellation, with strong autonomous operating capacity, will play a greater role in natural disaster responses, environmental protection monitoring and transportation industry, the company said.

Every satellite in the Xingshidai constellation will have the capacity to independently operate, and the constellation as a whole will have a self-coordination function, Wang Long, project manager for the plan at ADASpace, told the Global Times on Sunday.

"The coordinated smart system will independently analyze the data it obtains rapidly and decide what data should be sent back to the ground, or what orders it should carry out for the next step. This could shorten the time that would otherwise be needed to receive orders from the ground for every little move," Wang said.

The constellation will be comprised of remote sensing satellites with varied resolution ratios of 5, 1 and 0.5 meters.

Spacety, a satellite start-up based in Changsha, capital of Central China's Hunan Province, is one of ADASpace's supplying partners that produce satellites for the project.

ADASpace has strong AI research capacity, and the applications of AI satellite constellations are promising. Efficiency will be hugely improved and there are vast market prospects, Yang Feng, CEO of Spacety, told the Global Times on Sunday.

Huang Zhicheng, an expert on space technology, told the Global Times on Sunday that the Xingshidai project is a positive exploration of AI constellation management, which represents rapid development of China's thriving aerospace industry.

However, Huang noted that to fully realize AI management of satellite constellations, China still needs to make technology breakthroughs in key areas including chips, radar and optical devices.

 

[JSCh]

China unveils cloud-tech platform to serve commercial space industry
Source: Xinhua| 2019-06-28 11:18:55|Editor: Yang Yi

SHENZHEN, June 28 (Xinhua) -- The Chinese Academy of Sciences (CAS) has unveiled a cloud technology-based data platform tailored to the commercial space industry.

The Space Cloud Cubic platform launched Wednesday in Shenzhen, south China's Guangdong Province, is developed to provide comprehensive solutions to various parties in the commercial space industry, the CAS said.

Developed by CAS Tianta Co. Ltd., the platform has six major functions, including cloud measurement and control, cloud management, cloud communication, cloud storage, cloud computing, and cloud services.

The platform is expected to lower the threshold into the commercial space industry, bring the high-end aerospace technologies and innovations into life, according to CAS Tianta.

It is capable of serving the measurement and control management of the spacecraft, data communication and processing, as well as the related industry application.

Providing services of data storage and data computing, the cloud-tech platform will be helpful for its customers in cutting expenses and reducing difficulties in developing the satellite application system.

CAS Tianta and Alibaba Cloud, the data intelligence branch of Alibaba Group, has signed a framework cooperation agreement in joint development of products and services under the Space Cloud Cubic platform.

 

[JSCh]

https://twitter.com/x/status/1133296376182272000

OneSpace@OneSpace01

Thumbs up for our colleagues！We successfully completed 2500N bipropellant thruster hot fire test at 21st of May, this thruster is designed for precision attitude, trajectory and orbit control.

4:58 PM - May 28, 2019

https://twitter.com/x/status/1145873700094300160

 

[JSCh]

China's FAST telescope identifies 84 pulsars
Source: Xinhua| 2019-07-03 15:26:29|Editor: Li Xia

GUIYANG, July 3 (Xinhua) -- China's Five-hundred-meter Aperture Spherical Radio Telescope (FAST), the world's largest single-dish radio telescope, has discovered 84 new pulsars since its trial operation began in September 2016, Jiang Peng, FAST chief engineer told Xinhua on Wednesday.

A pulsar is a highly magnetized, rotating neutron star, which emits two beams of electromagnetic radiation.

Pulsar observation is an important task for FAST, which can be used to confirm the existence of gravitational radiation and black holes and help solve many other major questions in physics.

FAST is also in charge of the exploration of interstellar molecules and interstellar communication signals.

In order to better understand the evolution of the universe, the research team of FAST is ready to conduct an in-depth research on the distribution and status of cold gas in and around the galaxy, the circulation of gas within the galaxy, as well as other related frontier issues, according to Jiang.

Located in a naturally deep and round karst depression in southwest China's Guizhou Province, FAST is believed to be the world's most sensitive radio telescope.

 

[JSCh]

JUNE 26, 2019 REPORT
Highest energy photons ever recorded coming from Crab Nebula
by Bob Yirka , Phys.org

The Crab Nebula. Credit: NASA

A very large team of researchers affiliated with several institutions in China and Japan has measured the highest energy photon ever recorded. In their paper published in the journal Physical Review Letters, the group describes their study of data from the Tibet Air Shower Gamma Collaboration and what they found.

The Tibet Air Shower Gamma Collaboration is an observatory in the Tibetan Plateau and the people that run it. It consists of 600 particle detectors built on a 65,000-square-meter parcel of land. Its objective is to detect subatomic particles emanating from space. The detectors there observe the debris from photons colliding with particles in the Earth's atmosphere and cosmic rays, which are mostly protons and atomic nuclei. The team members with this new effort were focused on photons that make their way to Earth from far-off places. To measure them, the researchers excluded muon detections, leaving only particles associated with photon collisions. The researchers were able to calculate the energy of a given photon using data from the particles that it struck.

The researchers report that they found what they believe to be 24 photon-initiated showers, with photon energies above 100 trillion electron volts—one of which registered 450 TeV. These finds represent the first measurements of high energy photons over 100 TeV and the highest ever recorded.

The researchers also used the data from the collaboration to track the paths of the photons, and found they originated in the Crab Nebula, the remains of a supernova that exploded in 1054 AD. The Crab Nebula is located in the Perseus Arm of the Milky Way, approximately 6,500 light years away.

The research team has been studying high-energy photons that make their way to Earth as part of an effort to understand why they have so much energy. Current theory suggests that the photons get their energy from other high-energy particles via inverse Compton scattering, in which photons absorb the energy of high-energy particles when they collide, for example, during supernovae. The photons themselves are believed to have been created by processes involved in the Big Bang.


https://phys.org/news/2019-06-highest-energy-photons-crab-nebula.html

Scientists discover highest energy cosmic gamma rays in Tibet
Source: Xinhua| 2019-07-03 16:57:55|Editor: Li Xia

Photo taken on May, 2013 shows the ASgamma Experiment in Yangbajain, southwest China's Tibet Autonomous Region. A joint research team made up of Chinese and Japanese scientists has discovered the highest energy cosmic gamma rays ever observed from an observatory in Tibet, opening a new window to explore the extreme universe. (The Institute of High Energy Physics of the Chinese Academy of Sciences/Handout via Xinhua)

BEIJING, July 3 (Xinhua) -- A joint research team made up of Chinese and Japanese scientists has discovered the highest energy cosmic gamma rays ever observed from an observatory in Tibet, opening a new window to explore the extreme universe.

The energy of the gamma rays is as high as 450 TeV, equivalent to 45 billion times of the energy of X-rays for medical diagnosis, researchers from the Institute of High Energy Physics of the Chinese Academy of Sciences said at a press conference on Wednesday.

Scientists believe that those energetic gamma rays were from the Crab Nebula, a famous supernova remnant in the constellation Taurus, about 6,500 light years away from Earth.

Previously, the highest energy ever observed for a gamma-ray photon was 75 TeV, which was detected by the HEGRA Cherenkov telescope in Germany.

"Before this discovery, many scientists believed that photons could not be accelerated to energy higher than 100 TeV," said Huang Jing, a researcher from IHEP, and the co-spokesperson for the experiment.

"The discovery is a milestone in the search for the origin of the mysterious cosmic rays," said Professor Chen Yang, an expert of supernova remnants from Nanjing University.

Scientists hypothesize the following steps for generating very-high-energy gamma rays: first, the electrons are accelerated up to PeV (one thousand trillion electron volts) in the nebula; then the PeV electrons interact with the cosmic microwave background radiation (CMBR), the remnant radiation from the Big Bang filling the whole universe; and then a CMBR photon is kicked up to 450 TeV by a PeV electron.

The researchers thus conclude that the Crab Nebula is the most powerful natural electron accelerator known in our Galaxy.

The Crab Nebula was produced by a supernova explosion in the year 1054, which was recorded in official historical documents of the Northern Song dynasty (960-1127).

In 1969, scientists discovered a pulsar, rotating 30 times per second, embedded in the nebula. In the modern era, the Crab Nebula has been observed at all electromagnetic wavelengths ranging from radio to very high energy gamma rays.

The observatory, located in the Yangbajing town of Tibet at an altitude of 4,300 meters, has been operated jointly by China and Japan since 1990.

The China-Japan collaboration added new underground detectors in 2014, which can suppress 99.92 percent of the cosmic-ray background noises, and thus improve the sensitivity significantly, Huang said.

During a period of about two years, a total of 24 gamma-ray photons above 100 TeV have been detected from the Crab Nebula, as a result of the innovative upgrading of the experiment, according to Huang.

"This is the very first but a great step forward. It proves that our techniques worked well, and gamma rays with energies up to a few hundred TeV really exist," Huang said.

"This pioneering work opens a new window for the exploration of the extreme universe. The detection of gamma rays above 100 TeV is a key to understanding the origin of very-high-energy cosmic rays, which has been a mystery since their discovery in 1912. With further observations using this new window, we expect to identify the origin of cosmic rays in our Galaxy," Huang said.

The discovery will be published in the journal Physical Review Letters later in July.

 

[JSCh]

China航天
7月2日 19:03
【这项技术让低温火箭在轨时间可达30天】 近日，火箭院在“低温推进剂蒸发量控制技术”上取得突破，这项技术可以使我国低温火箭在轨时间延长到30天，为我国深空探测以及远距离空间运输提供了可行条件。该技术团队成员张少华介绍，低温火箭还有一个高冷的名字叫“冰箭”，它采用的液氢、液氧等低温化学推进剂无毒、无污染，经济实惠、效率高，因此在国内外运载火箭和上面级都得到了广泛应用。我国的长征五号运载火箭、长征七号运载火箭等都属于低温火箭。不过，低温火箭虽好，但长时间飞行却受到制约。在此之前，国内外低温火箭在轨时间大多只能维持在几十分钟到几小时之间O这项技术让低温火箭在轨时间可达30天

China航天
2nd July 19:03

[This technology allows cryogenic rockets to be in orbit for up to 30 days]
Recently, CALT has made a breakthrough in "Cryogenic Propellant Evaporation Control Technology". This technology can extend the in-orbit time of China's cryogenic rockets to 30 days, providing the conditions for deep space exploration and long-distance space transportation in China. Zhang Shaohua, a member of the technical team, said that the cryogenic rocket also has a nickname called "ice arrow". It uses cryogenic chemical propellants such as liquid hydrogen and liquid oxygen, which are non-toxic, non-polluting, economical and efficient, so is widely used in domestic and foreign launch vehicles and upper stage. China's Long March 5 and Long March 7 carrier rocket are all cryogenic rockets. However, although cryogenic rocket is good, it is restricted for long flight. Prior to this technological breakthrough, most of the cryogenic rockets' in-orbital time at home or abroad can only be maintained between tens of minutes and in hours.

New type polyurethane insulation foam under test​

 

[JSCh]

https://twitter.com/x/status/1146312860739481600

 

[JSCh]

China航天
2nd July 19:03

[This technology allows cryogenic rockets to be in orbit for up to 30 days]
Recently, CALT has made a breakthrough in "Cryogenic Propellant Evaporation Control Technology". This technology can extend the in-orbit time of China's cryogenic rockets to 30 days, providing the conditions for deep space exploration and long-distance space transportation in China. Zhang Shaohua, a member of the technical team, said that the cryogenic rocket also has a nickname called "ice arrow". It uses cryogenic chemical propellants such as liquid hydrogen and liquid oxygen, which are non-toxic, non-polluting, economical and efficient, so is widely used in domestic and foreign launch vehicles and upper stage. China's Long March 5 and Long March 7 carrier rocket are all cryogenic rockets. However, although cryogenic rocket is good, it is restricted for long flight. Prior to this technological breakthrough, most of the cryogenic rockets' in-orbital time at home or abroad can only be maintained between tens of minutes and in hours.

New type polyurethane insulation foam under test​

Scientists make breakthrough that enables rockets to orbit longer
Xinhua | Updated: 2019-07-05 12:20

BEIJING - Chinese scientists have made a breakthrough in cryogenic rocket engine technology that can extend the orbital period of rockets from a few hours to 30 days, providing support for China's future deep space exploration.

Cryogenic rocket engines are specially designed to work at extremely low temperatures. They use non-toxic and non-polluting propellants, such as liquid hydrogen and liquid oxygen, which are more cost-efficient than others.

The engine has been widely used in domestic and foreign launch vehicles, including China's Long March-5 and Long March-7 carrier rockets.

However, most of these rockets can orbit only a few minutes or a few hours. An extended orbital period has puzzled the aerospace community for a long time.

Scientists from the China Academy of Launch Vehicle Technology have developed two insulating materials that can reduce propellant evaporation loss and keep rockets in flight for longer than before.

According to Zhang Shaohua, a member of the research team, a cryogenic rocket will face a severe thermal environment when it flies in orbit, which will cause lots of propellant evaporation, accelerate propellant loss and reduce the time in orbit.

"If a car keeps leaking oil, its range will inevitably be shortened," said Zhang.

In addition, when a rocket is flying, its engine will expel the exhaust gases to keep pressure balance in the propellant storage tank. However, under the microgravity environment in space, gas and liquid cryogenic propellant will be mixed, therefore, a large amount of liquid propellant will also be discharged during engine exhaust.

One of the newly-developed materials is made of polyurethane foam, a chemical composition, which can increase the insulation capacity by more than 50 percent compared with traditional foam materials. The other one using variable density multilayer insulation also shows improved thermal performance, about 18 percent higher than traditional materials.

The test results showed that with the two advanced materials, the daily evaporation of cryogenic propellant can be cut down from 2.5 percent to 0.5 percent, said Zhang.

The material technology breakthrough realizes long-term storage of cryogenic propellant in orbit, proving its readiness for China's future deep space exploration and long-distance space transportation, Zhang said.