At 1.40am this morning, China launched a new Space Race with the world's first quantum satellite, recently named Micius after an ancient Chinese philosopher and engineer, who, more than 2,400 years ago, proposed that light always travelled in a straight line and that the physical world was made up by particles. Quantum teleportation technology would be able to eliminate the 20-minute time delay in communication between earth and Mars and would allow tiny spacecraft to send back images and videos of planets many light years away without the need to carry a huge antenna. It could even give us a glimpse of what’s inside a black hole.
The small object began its journey into space on top of a Long March 2D rocket launched from the Jiuquan Satellite Launch Center in Inner Mongolia’s Gobi Desert. The Quantum Experiments at Space Scale (QUESS) satellite, which successfully entered orbit at an altitude of 500 kilometers is believed to be the first of a fleet of quantum-enabled satellites, which will together create a super-secure communications network, potentially linking people anywhere in the world.
The satellite, weighing less than a Smart car, will be looking for a universe different from Einstein’s. One where a cat can be alive and dead at the same time, where bits of information can be “teleported” from one galaxy to another faster than the speed of light, where the internet cannot be hacked, and where a calculator can run faster than all the world’s super computers combined.
“The QSS missions are something never attempted by other nations,” Wang said. “China has been trailing the footsteps of others for more than a century. QSS will be our first step ahead of others. It is a tiny step, but it is a step for the human race.”
Eventually, quantum teleportation in space could even allow researchers to combine photons from satellites to make a distributed telescope with enormous resolution creating an aperture the size of Earth. “You could not just see planets,” says Kwiat, “but in principle read licence plates on Jupiter’s moons.”
Quantum properties – the states of a particle – cannot be measured or cloned without destroying the particle’s original quantum states, so the cryptographic keys, in theory, could not be stolen. A message would encrypted by a unique cryptographic key chain in Beijing and sent to Vienna through the conventional telecommunications network. At the same time, the key chain would be beamed to the quantum satellite by Beijing in the form of photons with various quantum properties such as clockwise or counterclockwise spins, and then the satellite would relay the cryptographic keys to the receiver in Vienna to decipher the message.
“The quantum satellite will for the first time prove that quantum communication on a worldwide scale is possible,” Wang said. “This is a crucial step to the future quantum internet.”
Eight years ago, quantum physicist Pan Jianwei, the project’s chief scientist. and space engineer Wang Jianyu teamed up to build the world’s first quantum satellite in the hope of finding the portal to a whole new universe. “Pan has some big ideas, my job is to squeeze them in a satellite,” Professor Wang, commander in chief of China’s quantum science satellite (QSS) project, told the South China Morning Post in an exclusive interview.
“Definitely, I think there will be a race,” says Chaoyang Lu, a physicist at the University of Science and Technology of China in Hefei, who works with the team behind the Chinese satellite.
“Originally, the army wanted to take over the responsibility [to bring quantum technology to space],” Pan told Nature magazine in January. “We at the CAS really worked hard to convince our government that it is important that we have a way to launch science satellites … it was finally agreed that CAS is the right organisation.”
As well as making communications hack-proof, these satellite systems would mark a major step towards a ‘quantum internet’ made up of quantum computers around the world, or a quantum computing cloud, says Paul Kwiat, a physicist at the University of Illinois at Urbana–Champaign who is working with NASA on the ISS project.
So far, scientists have managed to demonstrate quantum communication up to about 300 kilometres. Photons travelling through optical fibres and the air get scattered or absorbed, and amplifying a signal while preserving a photon’s fragile quantum state is extremely difficult.
At the core of Micus is a crystal that produces pairs of entangled photons, whose properties remain entwined however far apart they are separated. The Chinese researchers hope that transmitting photons through space, where they travel more smoothly, will allow them to communicate over greater distances. The craft’s first task will be to fire the partners in these pairs to ground -stations in Beijing and Vienna, and use them to generate a secret key.
During the two-year mission, the team also plans to perform a Bell test to prove that entanglement can exist between particles separated by a distance of 1,200 kilometers. The Chinese researchers hope that transmitting photons through space, where they travel more smoothly, will allow them to communicate over greater distances, and attempt to ‘teleport’ quantum states, using an entangled pair of photons alongside information transmitted by more conventional means to reconstruct the quantum state of a photon in a new location.
Though all the technology and equipment has been tested on the ground, there’s no guarantee it will all work in space. In a ground experiment, the equipment can be fine-turned or fixed; once in space, the hardware on the satellite cannot be modified.
Wang said the biggest challenge was distance. To beam a single photon from the satellite to a one-metre-wide telescope on the ground, or to catch a single photon from the ground with a satellite moving at 7,000km/h to 8,000km/h, with rain, clouds and air turbulence in between, would be “the most difficult sniper shot ever”, he said.
Development of the quantum satellite had taken China’s space technology to new heights in many areas, he said, including ultra-precise tracking, timing and spacecraft control.
But what if the experiments do not find what they are looking for, for instance the particles fail to entangle beyond a certain distance. Wang said it was something he had discussed with Pan. “If the QSS shows some fundamental laws of quantum physics do not work in the universe, we will be equally thrilled,” he said. “It will open another door to the unknown.”
The Daily Galaxy, 2016-08-16, Source: http://www.dailygalaxy.com/my_weblog/2016/08/-china-launches-new-space-race-with-worlds-first-quantum-satellite-a-portal-to-a-whole-new-universe.html