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News Article | January 6, 2016
Site: www.nature.com

A Swiss company is set to become the first firm to capture carbon dioxide from the air and sell it on a commercial scale, a stepping stone to larger facilities that could one day help to combat global warming. Around July, Climeworks will start capturing some 75 tonnes of CO per month at its plant near Zurich, then selling the gas to nearby greenhouses to boost crop growth. Another company — Carbon Engineering in Calgary, Canada, which has been capturing CO since October but is yet to bring it to market — hopes to show that it can convert the gas into liquid fuel. Facilities worldwide already capture the gas from power-plant exhausts, but until 2015 only small demonstration projects sucked it up from air. Human trials will get under way for treatments that use DNA-editing technologies. Sangamo Biosciences in Richmond, California, will test the use of enzymes called zinc-finger nucleases to correct a gene defect that causes haemophilia. Working with Biogen of Cambridge, Massachusetts, it will also start a trial to look at whether the technique can boost a functional form of haemo-globin in people with the blood disorder β-thalassaemia. Scientists and ethicists hope to agree on broad safety and ethical guidelines for gene editing in humans in late 2016. And this year could see the birth of the first gene-edited monkeys that show symptoms of the human disorders they are designed to model. Physicists think there is a good chance that they will see the first evidence of gravitational waves — ripples in space-time caused by dense, moving objects such as spiralling neutron stars — thanks to the Advanced Laser Interferometer Gravitational-Wave Observatory (Advanced LIGO). And Japan will launch Astro-H, a next-generation X-ray satellite observatory that, among other things, could confirm or refute the claim that heavy neutrinos give off dark-matter signals known as bulbulons. Hints of a potential new particle from the supercharged Large Hadron Collider (LHC), which has been running at record energies since last June, could become clearer as the machine rapidly accumulates data. Even if the particle is not confirmed, the LHC could still unearth other exotic phenomena, such as glueballs: particles made entirely of the carriers of the strong nuclear force. Scientists will soon hear whether funding for research that makes viruses more dangerous can resume. In October 2014, the US government abruptly suspended financial support for ‘gain-of-function’ studies. These experiments could increase understanding of how certain pathogens evolve and how they can be destroyed, but critics say that the work also boosts the risk of, for example, accidental release of deadly viruses. A risk–benefit analysis was completed in December 2015, and the US National Science Advisory Board for Biosecurity will issue recommendations in the next few months on whether to resume funding — potentially with tightened restrictions on the research. One lucky research group will win a $50-million grant for heart-disease research from Internet giant Google and the American Heart Association. Google’s disease-research portfolio is growing, and neuroscientists are eager to see what Thomas Insel, former director of the US National Institute of Mental Health, will do at the firm, where he has been leading a mental-health effort since November. Private funding could also make its mark in space: the non-profit Planetary Society in Pasadena, California, plans to launch a US$4.5-million mission in April to test its light-driven spacecraft, LightSail. The orbits of Earth and Mars will bring the planets close to each other this year, creating the perfect opportunity for a trip to the red planet. A joint mission between the European Space Agency (ESA) and Roscosmos will capitalize on that chance. Launching in March, ExoMars 2016 will analyse gases in Mars’s atmosphere and test landing technology. Farther afield, NASA’s Juno mission will arrive at Jupiter in July. In September, ESA’s craft Rosetta will make a death dive into the comet it orbits; mourners can console themselves with the launch of NASA’s OSIRIS-REx, a mission to bring back samples from the asteroid Bennu. Hot on the heels of the launch of the US$100-million Dark Matter Particle Explorer (DAMPE) last December, China’s National Space Science Center will launch the second and third space-science probes in its planned series of five. The world’s first quantum communications test satellite will blast off in June, and the Hard X-ray Modulation Telescope — which will scour the sky for energetic sources of radiation, such as black holes and neutron stars — will fly by the end of the year. September will see China complete construction of the 500-meter Aperture Spherical Radio Telescope (FAST), which will supersede Puerto Rico’s Arecibo Observatory as the world’s largest radio telescope. In Hawaii, the team behind the controversial Thirty Meter Telescope, which had its construction permit revoked in December, will try to work out whether and how it can move the project forward. The first results from an ambitious project to analyse the world’s microbial communities are expected this year. The Earth Microbiome Project, which launched in 2010, aims to sequence and characterize at least 200,000 samples of microbial DNA taken from everything from Komodo dragon tongues to soil in the Siberian tundra. The project promises to uncover unprecedented levels of biological diversity. In November, the United States will elect a new president. If a Republican takes the White House, long-debated plans to bury nuclear waste at Yucca Mountain in Nevada may well resurface, and federal funding for climate and social science could face the chop. And if Canada’s Liberal government lives up to its pre-election promises, the country will get a chief science officer, who researchers trust will arrive with a drive to rebuild the depleted ranks of government scientists. Neuroscientists hope to finally identify genes that are crucial to regulating the timing and duration of sleep but have been difficult to tease out, possibly because they also have other functions in the brain. Pinpointing these genes could shed light on sleep disorders and some psychiatric illnesses, which scientists now realize are linked to highly disrupted sleep patterns. The SESAME (Synchrotron-light for Experimental Science and Applications in the Middle East) facility will switch on in Jordan towards the end of 2016. The ring-shaped particle accelerator will generate intense light to probe materials and biological structures down to the atomic level. It is the region’s first major international research facility, and a rare collaboration between governments including Iran, Israel and the Palestinian Authority. Support to build a similar facility in Africa is likely to gather pace. And in June, scientists will get to use bright X-ray beams at the world’s first fourth-generation synchrotron, MAX IV in Lund, Sweden.


Li X.,National Space science Center | Zheng J.,National Space science Center | Wu X.,National Space science Center
Beijing Hangkong Hangtian Daxue Xuebao/Journal of Beijing University of Aeronautics and Astronautics | Year: 2012

The analysis of gravity-assist effects is of great importance on the design stage to specify both the swingby sequence and the initial parameters. An improved Tour-Map graphical method for this purpose was introduced, which permits a quick identification of key parameters in ballistic gravity-assist. By the patched conic assumption, the graphical method was developed according to the geometric relationship of excess velocity and the position and velocity of the gravity-assist planet, followed by analytical developments of key heliocentric orbit elements after swingby, such as period, inclination and eccentricity. Then the complicated requirements of gravity-assist was described as contours on two dimensional Tour-Map conveniently. A design example of high-inclination solar orbit with Jupiter assist was included to illustrate the usage.


He H.,National Space Science Center | Xie W.,National Space Science Center | Peng X.,National Space Science Center
Proceedings of the International Astronautical Congress, IAC | Year: 2013

An integrated monitoring system was developed for monitoring the operational status of sounding rockets. Driven by real- Time data, the system eliminated abnormal data which were spoiled in transmission process, exhibited information, such as sounding rocket's trajectory, attitude, rocket's key components' working status, movement and scientific data during launch phase, in a variety of ways such as three-dimensional view, two-dimensional view, curves, charts, and etc. After launching mission, the system can re-exhibit history launching process in the same way by history data which were recorded during real- Time mission. The experiments proved that the integrated monitoring system provided a powerful tool for monitoring real- Time status of launching missions, supporting post- Analysis and evaluation for missions. Copyright ©2013 by the International Astronautical Federation.


Wang Z.,National Space Science Center | Xie C.,National Space Science Center | Xiong W.,National Space Science Center
Proceedings of the International Astronautical Congress, IAC | Year: 2013

This article describes a much simplified, Digital and analog mixed architecture that support general S-band transponder operation. The mass is reduced to under 1.4kg (including TCXO), and the dimension is about 170 *70*100mm. The power consumption is less than 11W measured in the side of 28V input with 1W SSPA transmitter output. The mass cut down is benefit mainly from the progress of digital design techniques and the improvement of the FPGA technologies. The designer implements the IF command and tracking demodulation by a 3 million system gates FPGA. Furthermore, the device is employed with tri-mode-redundancy. The algorithm of the main carrier tracking is based on phase lock loop, the command demodulation is based on Costas loop for sub carrier tracking and DTTL loop for bit synchronization. The carrier acquisition threshold is under -128 dBm with PM/BPSK demodulation losses < ldB. The dynamic range is from -128 dBm to -55 dBm. The second technique that decreases the complexity is the structure of RF front-side. We use a small size saturated amplifier replacing the AGC amplifier, the saturation amplifier depresses the mostly of the signal dynamic and DSP deal with the dynamic left. We select a low power A/D converter with working frequency under 3Msps in under-sampling mode; however, the IF frequency is about 9.3MHz that can diminish the order of RF front-side down converter and the difficulties of analog band pass filter design. For the standard of the USB transmitter is only support modulation type: BPSK/PM, so we build a RF-IF close loop transmitter architecture that eliminate the components used in up converter architecture, the saved mixers and band pass filters extremely reduce the amount and the volume of PCB. Moreover, we creatively put the coherent forwarding signal generator and the Frequency-Phase Detector together in FPGA. The digital phase noise or jitter is wonderfully filtered by a well-designed analog low pass loop filter. To conclude, there is not any DAC or RF-filter in transponder's transmitter loop. The other advantage is that we can adjust the modulation index easily by digital parameter. The transponder developed by NSSC is under flight verification. ©2013 by the International Astronautical Federation. All rights reserved.


Yin H.,National Satellite Meteorological Center | Lan A.,National Space Science Center | Zhang S.,National Space Science Center
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2014

When observing unchanging targets or slow-changing targets, a rotating array can be used instead of a stationary array in an interferometric radiometer to reduce the complexity and the cost. The configuration of a stationary array determines its coverage in spatial frequency domain. But for a rotating array, the baselines were distributing on a series of concentric circles with radiuses of the baseline lengths, no matter what its configuration was. According to the characteristics of the distribution of the baselines, the expressions of system sensitivity and spatial resolution of a rotating interferometric radiometer were deduced in thwas paper. For a rotating interferometric radiometer with big synthetic aperture, like the Geostationary Interferometric Microwave Sounding (GIMS) prototype, it was very difficult to find a suitable calibration source to measure the system sensitivity. Therefore, the system sensitivity of the GIMS prototype was estimated based on the sensitivity of all channels by the sensitivity formula. Since the array factor of an interferometric radiometer was the pulse response of a point target, the spatial resolution of the GIMS prototype obtained by imaging an artificial quasi point target was used to demonstrate the formula in this paper, and the results were nearly identical. In addition, some different window functions were used to weight visibility samples of the prototype, and their effects on the sensitivity and the spatial resolution were analyzed. The principle of selecting the weighted window was described at the end. © 2014 SPIE.


News Article | April 19, 2016
Site: phys.org

A photo in China Daily showed two-cell mouse embryos, four hours before launch. The report said that mouse embryos carried by the return capsule completed the entire developing process within 96 hours from the launch, the first reported successful development of mammalian embryos in space. Therein lies the significance of this exploration. A researcher and professor said that there now was proof that the most crucial step in our reproduction – early embryo development – was possible in outer space. What is China's SJ-10? This is a microgravity satellite which launched on April 6. According to China Daily, "The return capsule on the satellite will stay in orbit for several days before heading back to Earth. An orbital module will continue to conduct experiments for a few more days." Actually, the Shijian-10 (SJ-10) spacecraft carries 20 experiments covering fluid physics, materials science, and the effects of radiation and microgravity on various biological systems, according to Science. That report on the spacecraft talked about the kinds of tests at play. Science quoted National Space Science Center (NSSC) Director General Wu Ji in Beijing, who referred to the scientific payload as a grab bag of experiments. Science described them: "Two combustion experiments will test how materials used in spacecraft burn in space to find ways of making safer capsules for human spaceflight, for example, while another experiment will study crystal growth in semiconductor materials and alloys. Three experiments will investigate how radiation affects genetics, also partly to make future human spaceflight safer. Early mouse embryos will be watched to see whether they develop normally, for clues to whether humans or other mammals could reproduce in space." Nonetheless, these are only clues about reproduction in space and scientists will need to figure out whether it is possible for us to survive and reproduce in outer space environments as we do on Earth, said Duan Enkui, Professor of the Institute of Zoology affiliated to the Chinese Academy of Sciences, and principal researcher of the experiment. Items and research process: The SJ-10 carried over 6,000 mouse embryos in a self-sufficient enclosed chamber. China Daily said it was the same size as a microwave oven. "A camera takes pictures of the embryos every four hours and sends the pictures back to Earth. It turns out some embryos developed into advanced blastocysts in four days." Next steps: "After the embryos are recovered from the returning capsule, scientists will immediately transport them to Beijing and perform further analyses on the developmental speed and changes in embryonic gene and protein expression."


News Article | December 23, 2015
Site: www.nature.com

Against a purple morning sky, in a cloud of brown smoke, the Monkey King took off. China’s first space-based dark-matter detector — nicknamed Wukong (or Monkey King) after a warrior in a sixteenth-century Chinese novel — rocketed into the air on 17 December, marking the start of a new direction in the country’s space strategy. From Earth’s orbit, the craft aims to detect high-energy particles and γ-rays. Physicists think that dark matter — a substance thought to make up 85% of the Universe’s matter but so far observed only through its gravitational effects — could reveal itself by producing such cosmic rays as its constituent particles annihilate. Wukong, officially called the Dark Matter Particle Explorer (DAMPE), is also notable for being the first in a series of five space-science missions to emerge from the Chinese Academy of Sciences’ Strategic Priority Program on Space Science, which kicked off in 2011. China is already one of the world’s major space powers, but so far has focused on human and robotic exploration, with little investment in space science. (A notable exception is the Double Star probe launched in collaboration with the European Space Agency in 2003 to study magnetic storms on Earth.) The DAMPE lift-off from the Jiuquan Satellite Launch Center in northern China will be followed next year by a further two missions: the world’s first quantum-communications satellite and an X-ray telescope observing in a unique energy band. Together, these missions mark a new start for space science in China, says Wu Ji, director-general of the National Space Science Center (NSSC), which runs the programme. Other countries have had Moon missions, adds Pan Jian-Wei, chief scientist for the quantum-science satellite, but with the space-science satellites, “we can do something new and something really great and not only for China — for the whole world”. The public gave DAMPE its nickname, Wukong, earlier this week, as part of an outreach drive in China’s space programme; a similar open effort also produced the name Yutu, or Jade Rabbit, for the nation’s lunar rover, which landed in 2013. Wukong will use its relatively large detection area to observe high volumes of cosmic rays, as well as where they come from. It will survey the sky at energies much higher than do existing detectors such as the Alpha Magnetic Spectrometer (AMS), which is currently attached to the International Space Station. “We don’t know if this is a better way to search for dark matter, because dark matter has not yet been found,” says Michael Capell, an AMS physicist at CERN, Europe’s particle-physics laboratory near Geneva, Switzerland. The detector could help to clear up some mysteries. In 2013, the AMS team announced that it had seen hints of dark matter, but so far it has detected too few high-energy particles to say for sure. DAMPE lacks the equipment to clarify the situation directly, but it could reveal whether the signal is from an astrophysical source other than dark matter, such as pulsars, says Capell. Although it will collect fewer incoming photons than existing γ-ray telescopes such as NASA’s Fermi-LAT, DAMPE is better at pinpointing the energies of these particles, says Miguel Sánchez-Conde, a physicist at the Oskar Klein Centre for Cosmoparticle Physics in Stockholm. This capability should allow DAMPE to see sharp spikes in radiation that are predicted by some dark-matter models. The two experiments that will follow hot on Wukong’s heels are no less ambitious. The quantum-science satellite, to launch in June, will be the world’s first space experiment to probe the phenomenon known as quantum entanglement. The mission will test whether a pair of entangled photons beamed from the satellite to two ground stations can remain entangled over a record-breaking distance of more than 1,000 kilometres. The experiment will also test whether a quantum connection can be set up between a ground station and the satellite and used to ‘teleport’ information instantly and securely. Previously, such experiments have transmitted photons on Earth through optic fibres or air, and over much shorter distances. The eventual goal is to create a global quantum-communications network, says Anton Zeilinger, a physicist at the University of Vienna who is collaborating with Pan on the quantum satellite. By pushing the limits of quantum entanglement, Pan says, the satellite may also help to solve fundamental mysteries about the Universe, such as how to unite quantum mechanics with Einstein’s theory of general relativity. In the second half of the year, China will launch the Hard X-ray Modulation Telescope (HXMT), looking for bright and brief sources of radiation, such as growing black holes. The HXMT will do a broad sweep of the sky, with a sensitivity at the top of its large energy range that exceeds those of existing wide-field telescopes, says Luigi Piro, an astronomer at Italy’s National Institute for Astrophysics in Rome. All three are cutting-edge missions, with the potential to make real discoveries, says Wu — but he is still not satisfied. Space science in China is funded in 5-year cycles, receiving around 3 billion yuan (US$460 million) in the current round. As a result there is no permanent funding, unlike in the United States and Europe, which makes it difficult to make long-term plans. “We don’t feel it is secure,” says Wu. “It is better than nothing. But we are still catching up.” He believes that until China makes discoveries in space science, “we are not a real space power”. The current funding round runs out next year. Although Wu thinks that the Chinese Academy of Sciences will continue to support the programme for another five years, that will be confirmed only next year. The funding will have to cover the remaining two missions — a satellite, Shijian-10, to conduct microgravity and life-sciences experiments, and a space-weather satellite known as Kuafu. Piro notes that most of the present and future Chinese scientific satellites include research contributions from scientists worldwide. Such collaborations “sharpen scientific goals, optimize resources and avoid overlap”, he says. Zeilinger attributes China’s pioneering work in space-based quantum communications to fast decision-making processes “oriented towards getting things done”. The US Congress passed a law in 2011 that prevents NASA from collaborating with China except in rare circumstances. By contrast, the European Space Agency wants to work with China and is already collaborating with the Chinese academy on a small space-weather observatory, the Solar wind Magnetosphere Ionosphere Link Explorer (SMILE). China’s limited experience in space science, alongside its politics, has hampered collaboration so far, says Joan Johnson-Freese, who specializes in China’s space programme at the US Naval War College in Newport, Rhode Island. But the country is anxious to develop and establish its expertise, she adds. Chinese scientists would like to collaborate with the United States, says Wu, but the severed ties hurt the United States more than China. “It gave a good chance for the Europeans. The US should realize that.


News Article | December 23, 2015
Site: www.techtimes.com

Scientists reported on Monday, Dec. 21, that China’s ground stations received data from its first satellite dedicated to investigating dark matter. A Kashgar station situated in Xinjiang tracked and obtained data from “Wukong,” officially known as the Dark Matter Particle Explorer (DAMPE) Satellite, last Sunday, Dec. 20 at 8:45 a.m., taking around seven minutes to receive and record the data. The information signifies that a transmission link was successfully established between DAMPE and ground stations. It was then transmitted to the National Space Science Center, reported the Chinese Academy of Sciences (CAS) in a statement. The satellite also sent data to ground stations in Miyun District, Beijing and in Sanya in the province of Hainan. CAS announced that the data received is in the right format and of good quality. China launched DAMPE to seek high-energy particles to learn further about dark matter, the mysterious and unseen force believed to make up a majority of the mass of the universe. It was dubbed “Wukong” (Monkey King) to honor a character from the classic novel “Journey to the West.” Carried into orbit by a Long March 2D rocket of the country, DAMPE is a collaborative project led by CAS, the University of Geneva and various academic institutions from Italy. DAMPE boasts of a massive surface area, not only capably observing high cosmic ray volumes but also surveying the sky at high energies. It uses four instruments for capturing the high-energy particles and tracing them back to their origin: a BGO calorimeter, a plastic scintillator detector, a neutron detector and a silicon-tungsten tracker. The particle sources are believed to be dark matter collisions, possibly giving scientists new insight into the dark matter. “[It’s] an exciting mission,” said Princeton University’s David Spergel of the DAMPE mission. A recent study in the Astrophysical Journal proposed that the solar system might be growing dark matter “hairs,” speculated to exist and sprout from Earth. Dark matter has evaded over three decades of research but has indirect proof in the cosmos, such as a powerful gravitational pull in action. "When gravity interacts with the cold dark matter gas during galaxy formation, all particles within a stream continue traveling at the same velocity," explained study author Gary Prézeau. Dark matter can potentially help scientists follow a wealth of scientific pursuits, including studying oceanic depths on icy moons and mapping out layers of celestial bodies. DAMPE is part of the CAS program called Strategic Priority Program on Space Science, where China is launching four other space missions. The four-year initiative will launch two new satellites in 2016, one of which is touted as the first satellite for quantum communications and will probe if photos from Earth can be utilized as part of a quantum network. Another mission will situate an X-ray telescope with one-of-a-kind energy band sensing ability into orbit, aimed at monitoring black hole radiation.


News Article | December 18, 2015
Site: phys.org

China has successfully placed a satellite called the Dark Matter Particle Explorer (DAMPE) into a sun-synchronous orbit around the Earth. Its mission is to study high-energy particles and γ-rays as part of an overall objective to learn more about dark matter. The satellite was boosted into the sky by a Chinese Long March 2D rocket, launched from a northwest province in China. The satellite, nicknamed "Wukong" (Monkey King) by the Chinese public is part of a collaborative effort between China's Academy of Sciences, several academic institutions in Italy, and the University of Geneva—its launch marks a major advance for the country into the study of space science, from space. The satellite has four sensors onboard: a BGO calorimeter, a silicon-Tungsten Tracker a neutron detector and a plastic scintillator detector. Each is part of the overall goal to capture high energy particles and then to trace them back to their origin, which the team believes would be dark matter particle collisions. The sensors have been designed to detect photons and electrons with a higher resolution than can be found by testers residing in underground sensor facilities or the AMS aboard the International Space Station. Tracking dark matter back to its source, the team believes, should shed some light on dark matter itself, which continues to defy observation despite many efforts across the globe. One focused mission by the team working with data from DAMPE will be to see if the new satellite can be used to reveal the source of signals seen by AMS, such as if they are caused by pulsars or dark matter collisions. The DAMPE mission is the first of five space science missions the Chinese have developed—two more will take place next year–one of which is being billed as the first quantum-communications satellite (its purpose is to see if photons sent from ground stations to the satellite can continue to be entangled with their Earthbound counterparts, which, if so, could eventually lead to a quantum network.) The other mission will have the Chinese sending an X-ray telescope into orbit with unique energy band sensing capabilities—it will be used mostly to study radiation emitted from black holes. Director of the National Space Science Center, Wu Ji, told the press that the country is embarking on the new space science missions to seek further progress in the field.


News Article | March 9, 2016
Site: www.nature.com

In the wake of last month’s historic detection of gravitational waves by a US-led collaboration, a range of Chinese proposals to take studies of these ripples in space-time to the next level are attracting fresh attention. The suggestions, from two separate teams, are for space-based observatories that would pick up a wider range of gravitational radiation than ground-based observatories can. The most ambitious plan could give China an edge over the leading European proposal to detect gravitational waves from space, but whether a single country can achieve that on its own is unclear. Also under consideration are a possible collaboration between Chinese researchers and the European effort, and a cheaper Chinese plan. Although an Earth-based detector — the US Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) — was the first to confirm a prediction made by Albert Einstein a century ago, launching the field of gravitational-wave astronomy, such detectors can pick up only limited frequencies. Advanced LIGO compares laser light beamed along two perpendicular detector arms to reveal whether one beam has been compressed or stretched by gravitational waves. Each LIGO arm measures 4 kilo­metres, but picking up the frequencies that are richest in gravitational waves requires distances of hundreds of thousands of kilometres or more. This can be achieved only in space, where spacecraft equipped with lasers can be positioned at these distances. Space-based detectors also avoid fluctuations in Earth’s gravitational field, which can obscure signals. With such considerations in mind, the European Space Agency (ESA) is pursuing a space-based gravitational-wave detector. One of the Chinese proposals, Taiji, meaning ‘supreme ultimate’, is to create a more ambitious version of the leading proposal for the European project, which is called eLISA (Evolved Laser Interferometer Space Antenna). Like eLISA, Taiji would consist of a triangle of three spacecraft in orbit around the Sun, which bounce lasers between each other (see ‘China’s choices’). The distance between eLISA’s components is still under discussion, but current plans suggest it could be 2 million kilometres, says eLISA member Karsten Danzmann of the Max Planck Institute for Gravitational Physics in Hanover, Germany. Taiji’s spacecraft would be separated by 3 million kilometres, giving the detector access to different frequencies. Taiji would launch in 2033, slipping in a year ahead of eLISA’s current schedule. “If Taiji produces a Chinese version of eLISA, then it will bring China to the frontier,” says Yanbei Chen, a gravitational-wave physicist at the California Institute of Technology in Pasadena, who works on LIGO. Gerhard Heinzel, an eLISA physicist also at the Max Planck Institute in Hanover, cautions against a single country going it alone on such a large project. It “is definitely too big — mainly in terms of cost but also resources in terms of scientists and experts in the presence of competing science projects”, he says. Taiji project leader Wu Yue-Liang, a particle physicist at the Chinese Academy of Sciences’ Institute of Theoretical Physics in Beijing, estimates that the project will cost 14 billion yuan (US$2 billion), roughly twice as much as ESA is budgeting for its gravitational-wave detector. A second Chinese proposal, led by Luo Jun, a physicist at the Sun Yat-Sen University campus in Zhuhai, would lower the bar in terms of cost and resources. Called TianQin, a name that refers to the metaphor of nature playing a stringed instrument (a zither) in space, the project has three satellites that orbit Earth at a distance of about 150,000 kilometres from each other. It would cost 2 billion yuan, says Luo. TianQin would be more limited than Taiji in terms of what it could detect: rather than acting as an observatory for the waves emitted by myriad objects including black holes and neutron stars, it would mainly target a particular pair of orbiting white dwarf stars, called HM Cancri. TianQin’s simplicity makes it cheaper and more certain of success, Luo says. The spacecraft could launch in 15–20 years, he adds, around the same time as the Taiji group says that it could launch. Luo thinks that a simpler project is more realistic now, but says that TianQin could lay the groundwork for a Taiji-like project in the future. Wu Ji, director-general of the Chinese Academy of Sciences’ National Space Science Center, says that the TianQin and Taiji teams should merge. “If China decides to have a space gravitational mission, there should be an integrated one, with a new name probably. There is no way to support two missions at the same time.” Both Wu Yue-Liang and Luo are confident that their proposals will move forward to the concrete design phase in the next five years. Taiji currently receives money from the Chinese Academy of Sciences and TianQin from the city of Zhuhai — but both need much more cash. The LIGO discovery could increase their chances of success. The “government will know more the importance of fundamental research” in gravitational waves, says Wu Ji. “China should catch up in this area,” he adds. On 5 March, the Chinese central govern­ment released a draft list of 100 strategic projects that will be emphasized in the country’s next five-year plan, which includes “a new generation of heavy launch vehicles, satellites, space platforms and new payload” and a “deep-space station”. Chinese researchers could also end up collaborating with Europe. As well as its main project, the Taiji group has outlined the possibility of a direct collaboration with eLISA: it would either contribute 1.5 billion yuan directly or develop its own scaled-down, 8-billion-yuan version of eLISA that would coordinate closely with the European effort, sharing data. Heinzel recommends that a united Chinese group work on one of these less ambitious options. The direct contribution from China in particular could be a boon for eLISA. Originally, NASA collaborated with ESA on a planned space-based gravitational-wave observatory, named LISA. But the United States pulled out of LISA five years ago and ESA had to pare down the mission, resulting in the eLISA proposal. China’s entry into the project could fill that hole, says Rainer Weiss, a physicist at the Massachusetts Institute of Technology in Cambridge, who is credited as the chief inventor of LIGO. This would perhaps allow Europe to pursue a design closer to that of LISA, which was better equipped than the eLISA proposal and would have had a longer mission lifetime. A decision is needed soon if China is to achieve a launch date around 2030, cautions Heinzel. “Now is the time to do very serious technology development,” he says. “It is time to start making decisions.”

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