Pan hopes to help China launch its first quantum satellite in 2015. (Photo/CNS)
A prominent scientist in China has shared his plans to develop a quantum satellite within ten years.
Pan Jianwei, who is the youngest scientist at China's Academy of Science, said he entered his field purely out of interest. After receiving his master's degree from the University of Science and Technology in China, Pan went to the Universitat Wien in Austria for his PhD. When he graduated in 1999, quantum was not yet considered a crucial subject to research in China, and it took Pan several years to secure funds for his research.
As more and more quantum researchers sprung up in China, Pan found more partners for his projects. In 2009, Pan and his colleagues created the world's first quantum telephone network. Now Pan says he wants to complete a quantum satellite by year 2015. Pan has brought on board a former professor from Austria to assist with the project and says the project will help the nation.
A team of 15 Chinese researchers from Tsinghua University in Beijing and the Hefei National Laboratory for Physical Sciences, a government-directed research center, in May published a research paper announcing a successful demonstration of "quantum teleportation" (liangzi yinxing chuan) over 16 kilometers of free space.
These researchers claimed to have the first successful experiment in the world. The technology on display has the potential to revolutionize secure communications for military and intelligence organizations and may become the watershed of a research race in communication and information technology.
Although much of the science behind this technology is still young, quantum technologies have wide-ranging applications for the fields of cryptography, remote sensing and secure satellite communications. In the near future, the results from this experiment will be used to send encrypted messages that cannot be cracked or intercepted, and securely connect networks, even in remote areas, with no wired infrastructure, even incorporating satellites and submarines into the link .
Roots in quantum physics, applications in intelligence
Rather than transporting matter from place to place, quantum teleportation's most practical applications currently involve using photons for instantaneous, almost totally secure data communication. Using the term "teleportation" to describe this effect can be justified by what Albert Einstein called "spooky action at a distance": after two particles are linked together through quantum entanglement, any change in the state of one particle immediately alters the other, even from kilometers away. In effect, the state of the particle at the sender's end is destroyed and reappears as an exact replica at the receiver's end, with a negligible chance of undetected third-party interception .
While the teleportation of physical matter remains science fiction at this point, quantum teleportation could be immediately implemented as a means for secure communications and cryptography. Current encryption techniques are based upon mathematical functions involving very large prime numbers and secure key management and distribution, but this strategy has a number of drawbacks and is nearing the end of its shelf life.
In particular, as computing power continues to double every year and computer bits speed up through the use of quantum particles, the cryptographic keys used for encoding and decoding must now be changed more often to prevent encrypted data from being cracked. As a result, it has become very difficult to "future proof" the encryption of data, and were any major breakthrough in quantum computing to be achieved in the near future, current encryption techniques could become obsolete and encrypted data could suddenly become unprotected .
The security of using quantum teleportation to distribute cryptographic keys, on the other hand, is upheld by the laws of physics and has a seemingly infinite time horizon. These keys cannot currently be detected and cracked even with the help of the most powerful computers. Owing to the Heisenberg Uncertainty Principle, the quantum states of photons cannot be observed without changing the state of the particle, which has the result of immediately informing the sender and receiver of any eavesdropping. Quantum communication can thus be used to send the most sensitive information, including keys to decode encrypted data sent over less secure means.
Significance of the China's achievement
As a result, the issue has found itself at the center of a rapidly developing geopolitical race to apply quantum technology to military and intelligence work. Since secure quantum key distribution (QKD) provides a much higher level of security between communication networks, employing quantum teleportation over a satellite network allows for completely secure communications, even in sensitive and remote areas, without fiber optic infrastructure, as long as all parties are able to maintain line of sight with a satellite. This could have wide applications in communications and intelligence for ground troops, aircraft, surface ships and submarines, and fits into China's current plans to grow its satellite network even further.
Using quantum teleportation to send this type of information has been technically possible for several years, but according to the Chinese research paper, it had been previously demonstrated experimentally only over an enclosed fiber optics network and then only over a distance of several hundred meters .
The Chinese experiment appears to shatter these records by claiming to be the first to use a high-powered blue laser to exchange quantum information over a free space channel, and to demonstrate the principle over a distance as great as 16km. This distance is significant because it displays approximately the same degree of light distortion as is seen in communication from the earth's surface to a satellite, and so would allow for quantum communication using satellites. If this experiment were indeed the first of its kind, it would appear that China has succeeded in leapfrogging the West, and gained a significant edge in next-generation communications and cryptography.
A quantum space race?
The Chinese claim to be the first may not be entirely accurate, although certain elements of their experiment were unique and innovative. In 2005, a group of universities and defense corporations under a Defense Advanced Research Projects Agency (DARPA) grant and led by BBN Technologies, the company responsible for developing the precursor to the Internet, succeeded in transferring cryptographic keys over a free-space link of 23 km in Cambridge, Massachusetts.
Well beyond the single link employed by the Chinese, the BBN program has developed an expanding, multi-node web of secure quantum communication that will be able to further expand and link seamlessly with existing Internet technology . There are a few differences in the physics of their experiment that still make it notable and may not technically disqualify the Chinese from claiming their status as first, but nonetheless American researchers seem to have had a five-year head start in demonstrating the principles of the technology.
However, one notable difference between the Chinese and American experiments is that the Beijing experiment used a blue laser for their teleportation experiments while the BBN team had been employing infrared. Both have advantages and disadvantages in range and power, but the primary difference in their applications seems to be that blue and blue-green lasers penetrate further into water and so have wider applications for sub-surface communications. China is currently modernizing its submarine fleet as a way to project force further past its coastal waters to deter any US naval response to a potential invasion of Taiwan as well as doing significant research into laser communications in submarines .
Quantum laser links with satellites would allow sub-surface communication without most of the traditional downsides of radio communications and allow subs to operate with even greater autonomy and silence . Judging from the interest in blue lasers for underwater communication and the interesting choice of a blue laser for the teleportation experiment, it would be safe to venture a guess that applications for quantum communication are already beginning to find their way into Chinese military research and development.
Because of its security level and applications for satellite and submarine communications, quantum communication technology figures centrally in the objectives of the Chinese military to upgrade their growing command and control capabilities. A functional satellite-based quantum communication system would give the Chinese military the ability to operate further afield without fear of message interception.
However, Chinese researchers must also be aware of the potential for the United States to employ the same technology and may be seeking ways to counter this eventuality. While it is still almost impossible to intercept quantum messages without being detected, it may be feasible to jam the laser signals that send them with "optical noise" or other lasers. Understanding the ways in which quantum cryptography functions may also eventually expose further weaknesses in the network that can be exploited by a savvy adversary.
China's continuing cutting-edge quantum cryptography, lasers and optics research thus seems as much a reaction to the same research in the United States and an attempt to counter it as it is to develop its own indigenous network.
All of these potential uses are motivations for Chinese labs to be the first to develop successful applications of quantum technology for immediate deployment and to claim milestones like being the first to successfully execute teleportation over several miles of free space.
Besides the military uses and academic prestige, this accomplishment could attract a significant amount of international funding for China's developing optics industry, and if quantum teleportation becomes the new paradigm for the future of secure communications, China would like to make a name for itself as the premier research and development hub. Claims of this recent "first" for China then have that much greater significance for security and the continued health of US technological superiority.
1. Jin Xian-Min, et al. "Experimental free-space quantum teleportation." Nature Photonics 4, 376 - 381 (2010). Published online: May 16, 2010 doi:10.1038/nphoton.2010.87. See also the Chinese Academy of Sciences review.
2. Lei Zhang, Jacob Barhen, and Hua-Kuang Liu. "Experimental and Theoretical Aspects of Quantum Teleportation." Center foe Engineering Science Advanced Research, Computer Science and Mathematics Division, Oak Ridge National Laboratory (2000).
3. David Pearson, "Building a QKD Network out of Theories and Devices," BBN Technologies (December 2005).
4. The Chinese paper cites R Ursin, et al. "Quantum teleportation across the Danube" and I Marcikic, et al "Long-distance teleportation of qubits at telecommunication wavelengths," both descriptions of quantum cryptography over hundreds of meters of optical fiber.
5. Chip Elliott, et al. "Current status of the DARPA Quantum Network." In Quantum Information and Computation III, edited by Eric J. Donkor, Andrew R. Pirich, Howard E. Brandt, Proceedings of SPIE Vol. 5815 (SPIE, Bellingham, WA, 2005).
6. See Yingzhuang Liu and Xiaohu Ge, "Underwater laser sensor network: a new approach for broadband communication in the underwater." Department of Electronics & Information Engineering, Huazhong University for Science and Technology (May 2006).
7. These include detectability, the need to surface to communicate, limitations in range, and the reliance on cryptographic keys that may be cracked.
Matthew Luce is a researcher and Chinese linguist at Defense Group Inc’s Center for Intelligence Research and Analysis, where he does primary source research and analysis of China’s science and technology policies and development programs. Mr. Luce's research and writing focuses on cyber security, C4ISR-related technologies, and China's ethnic relations. He has worked and traveled extensively in China and speaks and reads fluent Chinese.
III. (China's)Major (Space)Tasks for the Next Five Years
In the next five years, China will strengthen its basic capacities of the space industry, accelerate research on leading-edge technology, and continue to implement important space scientific and technological projects, including human spaceflight, lunar exploration, high-resolution Earth observation system, satellite navigation and positioning system, new-generation launch vehicles, and other priority projects in key fields. China will develop a comprehensive plan for construction of space infrastructure, promote its satellites and satellite applications industry, further conduct space science research, and push forward the comprehensive, coordinated and sustainable development of China's space industry.
1. Space Transportation System
China will build a stronger space transportation system, keep improving its launch vehicle series, and enhance their capabilities of entering space.
It will enhance the reliability and adaptability of launch vehicles in service, and develop new-generation launch vehicles and their upper stages, implement the first flight of the Long March-5, Long March-6 and Long March-7 launch vehicles. The Long March-5 will use non-toxic and pollution-free propellant, and will be capable of placing 25 tons of payload into the near-Earth orbit, or placing 14 tons of payload into the GEO orbit. The Long March-6 will be a new type of high-speed response launch vehicle, which will be capable of placing not less than 1 ton of payload into a sun-synchronous orbit at a height of 700 km. The Long March-7 will be capable of placing 5.5 tons of payload into a sun-synchronous orbit at a height of 700 km.
It will conduct special demonstrations and pre-research on key technologies for heavy-lift launch vehicles.
2. Man-made Earth Satellites
China will build a space infrastructure frame composed of Earth observation satellites, communications and broadcasting satellites, plus navigation and positioning satellites, and will develop a preliminary long-term, sustained and stable service capability. China will develop new types of scientific satellites and technological test satellites.
1) Earth observation satellites
China will improve its present meteorological, oceanic, and resource satellite series and its small satellites constellation for environmental and disaster monitoring and forecasting. It aims at developing and launching new-generation GEO meteorological satellites, stereo mapping satellites, radar satellites for environment and disaster monitoring, electromagnetic monitoring test satellites, and other new-type Earth observation satellites. It will work to make breakthroughs in key technologies for interferometric synthetic-aperture radar and gravitational field measurement satellites. It will initiate a high-resolution Earth observation system as an important scientific and technological project and establish on the whole a stable all-weather, 24-hour, multi-spectral, various-resolution Earth observation system.
2) Communications and broadcasting satellites
China will improve satellites for fixed communications services, television and radio service satellites and data relay satellites; develop satellites for mobile communication service; and develop a platform of higher capacity and higher power for new-generation GEO communications and broadcasting satellites.
3) Navigation and positioning satellites
Based on "three-step" development plan - from experimental system to regional system and then to global system, China will continue building its Beidou satellite navigation system, implementing a regional Beidou satellite navigation system before 2012, whose navigation and positioning, timing and short-message services will cover the Asia-Pacific region. China aims at completing the global Beidou satellite navigation system by 2020, comprising five GEO satellites and 30 non-GEO satellites.
4) Scientific satellites and technological test satellites
China will develop and launch a Hard X-ray Modulation Telescope satellite, Shijian-9 new technology test satellite, and returnable satellites. It will begin to implement projects of quantum science test satellite and dark matter probing satellite.
3. Human Spaceflight
China will push forward human spaceflight projects and make new technological breakthroughs, creating a foundation for future human spaceflight.
It will launch the Shenzhou-9 and Shenzhou-10 spaceships and achieve unmanned or manned rendezvous and docking with the in-orbit Tiangong-1 vehicle.
China will launch space laboratories, manned spaceship and space freighters; make breakthroughs in and master space station key technologies, including astronauts' medium-term stay, regenerative life support and propellant refueling; conduct space applications to a certain extent and make technological preparations for the construction of space stations.
China will conduct studies on the preliminary plan for a human lunar landing.
4. Deep-space Exploration
China carries out deep-space exploration in stages, with limited goals.
Based on the idea of "three steps" -- orbiting, landing and returning -- for continuing lunar probe projects, China will launch orbiters for lunar soft landing, roving and surveying to implement the second stage of lunar exploration. In the third stage, China will start to conduct sampling the moon's surface matters and get those samples back to Earth.
China will conduct special project demonstration in deep-space exploration, and push forward its exploration of planets, asteroids and the sun of the solar system.
5. Space Launch Sites
China will enhance the reliability and automation level of launch site facilities and equipment, strengthen the comprehensive capability of launch of spacecraft, and satisfy the launch demands. It will also complete the construction of the Hainan space launch site and put it into service.
6. Space TT&C
China will improve its space TT&C network, build deep-space TT&C stations, develop advanced TT&C technologies, and enhance its TT&C capabilities in all respects to satisfy the demands for remote TT&C.
7. Space Applications
China will further improve its satellite application and service system, expand satellites application scope, and promote the national new strategic industries, to meet demands of national economic and social development.
1) Applications of Earth observation satellites
China will improve its ground facilities for receiving, processing, distributing and applying satellite data, and will strengthen the development of calibration fields and other facilities. It will improve the sharing and comprehensive application of data retrieved from Earth observation satellites, make more self-obtained space data, and guide social resources to actively develop market-oriented data application services. It will implement application demonstration projects, and promote the wide utilization and industrialization of Earth observation satellites.
2) Applications of communications and broadcasting satellites
China will strengthen the applications of communications and broadcasting satellites in public service and major industries of the national economy. It plans to expand value-added business in the satellite communication field, further commercialize satellite communication, and expand the industrial scale of the application of communications and broadcasting satellites.
3) Applications of navigation and positioning satellites
China will build and improve ground TT&C segments and develop a system for monitoring and assessing performance of the global satellite navigation system, strengthen technological research, product development and standardization system of navigation and positioning satellites, enhance application level, promote position-based services, expand the industrial scope, and focus on promoting further use of the Beidou satellite navigation system in various fields of China's national economy.
8. Space Science
China will strengthen the development of its space science research system, upgrade the quality of space science research, and enhance popularization of space science knowledge in the whole nation.
By the implementation of lunar exploration projects, China will make in-situ analyses, morphological and structural surveys of the lunar surface in landing and roving areas, conduct environmental surveys of the lunar surface and make moon-based astronomical observations.
By using spacecraft, China will study the properties of black holes and physical laws under extreme conditions, explore properties of dark matter particles, and test basic theories of quantum mechanics. It will also conduct scientific experiments on microgravity and space life science, explore and forecast the space environment and study their effects.
9. Space Debris
China will continue to strengthen its work on space debris monitoring and mitigation and its work on spacecraft protection.
China will develop technologies for monitoring space debris and pre-warning of collision, and begin monitoring space debris and small near-Earth celestial bodies and collision pre-warning work. It will set up a design and assess system of space debris mitigation, and take measures to reduce space debris left by post-task spacecraft and launch vehicles. It will experiment with digital simulation of space debris collisions, and build a system to protect spacecraft from space debris.