The global quantum space race
In August 2016, China launched Micius, a low Earth orbit satellite that proved secure, global quantum communications, and an unbreachable quantum internet, were very real prospects. The brainchild of China’s ‘father of quantum,’ Jian-Wei Pan, Micius was built to test the phenomenon of quantum entanglement and realize quantum key distribution (QKD)—encryption that allows data to be sent over a network without being hacked by a quantum computer—over unprecedented distances. Monumental breakthroughs followed.
By September 2017, Pan, a professor at the University of Science and Technology of China, Chinese Academy of Sciences, and colleagues, had set up the first-ever quantum-encrypted teleconference between researchers in China and Austria, some 2,850 miles apart. Micius created quantum encryption keys encoded within polarized photons and shared these first with a Beijing ground station, and then, as the Earth rotated and Austria came into view, with a Vienna ground station. These keys were used to encrypt the 75-minute video conference transmitted across a ground fiber-optic network.
In the same year, Micius generated pairs of entangled photons and simultaneously streamed these to two ground observatories in China, some 745 miles apart, showing these inextricably intertwined photons could survive long-distance transmission to Earth. Come 2020, the satellite had built on this experiment and demonstrated entanglement-based quantum cryptography—a more secure form of quantum encryption. Here, entangled photon pairs were simultaneously sent to two China-based observatories, nearly 700 miles apart, to create encryption keys and establish a secure quantum link between the ground locations.
“Micius has been an experimental tour de force—if there was ever a hero experiment, then that satellite is a good example,” says Daniel Oi, from the Computational Nonlinear and Quantum Optics (CNQO) group at the University of Strathclyde, Scotland.
Oi—also Director of the UK’s International Network in Space Quantum Technologies—has been working on quantum technologies since the early 2000s. As he puts it: “Back then, many scientific groups wanted to do quantum [communication] experiments in space but there just wasn’t funding. But China was always working on this...and nothing has rivalled the seismic shift that Micius represented.”
Since then, Micius has been connected via a ground station to China’s 2000 km, fiber-optic quantum link—the Beijing-Shanghai Trunk Line—forming the first integrated space-to-ground quantum communications network and a massive milestone towards a secure, quantum internet. Meanwhile, a small QKD satellite, Jinan-1, launched to join Micius and expand this remarkable network. Recent reports in China Business News indicate that up to three more satellites will follow in 2025 while the possibility of higher Earth orbit satellites—with greater coverage—have been touted in Yicai News.
Why the quantum rush? Jian-Wei Pan, and several colleagues from University of Science and Technology of China, did not respond to interview requests, but the benefits are clear. Unhackable quantum communications would benefit many sectors—think fraud prevention in finance, secure transmission of sensitive medical data, and immunity to decryption attempts in defense. Such a network would connect quantum computers, as well as sensors, so vast levels of processing power and data could be shared to perform the complex calculations that flummox classical computing. Examples include optimizing global supply chains, modelling complex molecular structures for drug discovery, and simulating global atmospheric patterns for climate change predictions. “Instead of having to transfer all of your data to a central processor for calculations, long-distance quantum links will enable these very powerful distributed quantum information processing tasks,” says Oi.
Global progress
China’s breakthroughs have hardly gone unnoticed, with numerous nations racing to develop and demonstrate their tech. In Canada, a low Earth orbit, small microsatellite—Quantum EncrYption and Science Satellite (QEYSSat)—is set to launch between 2025 and 2026. QEYSSat weighs around 100 kg, some 500 kg less than Micius, and will represent a huge leap forward for quantum space communications.
Funded by the Canadian Space Agency, and designed and implemented by multinational conglomerate Honeywell, QEYSSat has been pioneered by Thomas Jennewein, from the Institute for Quantum Computing (IQC), at the University of Waterloo. Collaborators come from the University of Waterloo and nine other Canadian universities, as well as institutions in Australia, Germany, Japan, Poland, and the UK, as well as NASA, and the US Air Force Research Laboratory (AFRL). All are keen to demonstrate quantum entanglement and QKD between ground and space.
As preliminary work for the QEYSSat mission, in 2016 Thomas Jennewein and colleagues set up a quantum uplink, generating a quantum secure key between an optical ground station in Ontario, Canada, and an airplane, seen as a streak in the night sky. Photo credit: University of Waterloo.
But while other quantum communication satellites, including Micius, have been designed to transmit quantum-encoded photons down to receivers at ground stations, the QEYSSat satellite will receive the quantum signals from a ground station—in effect, turning quantum communication on its head. “Many satellites are primarily downlink satellites and transmit signals from space to Earth as it can be easier to put your quantum source in space and keep your sensitive quantum detectors on the ground,” explains Katanya Kuntz, a research associate from Jennewein’s group and also QEYSS as Science Team Coordinator. “But we believe there’s an advantage in having your quantum sources on the ground as you can then more easily swap in your better technology as it develops.”
Ground station technologies investigated by QEYSSat collaborators include adaptive optics and ultra-bright entangled photon transmitters that could help to counter air turbulence in the long-distance satellite uplink. QEYSSat itself will carry a single telescope and detectors to capture incoming quantum-encoded photons from the ground station, having the necessary algorithms and processing power onboard to sift through the signals and form a secure key.
To set up secure quantum communications, QEYSSat will pass over a ground station, receive the encoded photons, and generate a secure key between itself and that ground station via QKD. That key will be stored as the satellite passes over another ground station for a further key exchange—and with two keys in tow, the satellite can then combine these, setting up the ground stations with a quantum-encrypted communications link.
“We want to demonstrate that we can set up quantum links over the entire country, but we only have one telescope on our satellite, so we make a link over one ground station and then fly over to another ground station to form the second link,” highlights Kuntz. “Micius had two telescopes on board and so could send entangled photons to two ground stations simultaneously.”
The mission’s primary quantum ground station will be built at the Canadian Space Agency headquarters in Quebec, and will perform QKD experiments with QEYSSat shortly after launch. The satellite will also test QKD at ground stations located at the University of Waterloo and the Rothney Astrophysical Observatory, University of Calgary, eventually venturing to stations beyond Canada to set up international quantum communications.
In a similar vein to Micius and the Beijing-Shanghai Trunk line, Kuntz and colleagues also hope to link QEYSSat to one of Canada’s quantum fiber-optic networks. One possibility is Quebec-based Kirq, a public-access quantum communication test-bed, set up to test quantum technologies including QKD. Another option is the city of Calgary’s metropolitan fiber-optic line, on which University of Calgary researchers demonstrated quantum teleportation over a few miles, back in September 2016.
“We’re in talks to link the Rothney Observatory to the Calgary network,” confirms Kuntz. “And this is where things get great as you could have a metropolitan user in Calgary and another in Montreal at, say the Royal Canadian Mounted Police headquarters, that need secure communication between the two cities—you could now do this using a secure key shared by QEYSSat.”
Like-minded plans are afoot in Europe. By early 2026, the European Space Agency (ESA) intends to launch a small satellite, Eagle-1, developed with Luxembourg-based satellite firm, SES, as part of a consortium of more than 20 European companies. Like Micius, this low Earth orbit satellite will carry its quantum-key payload, encrypting photons transmitted from ground stations in Germany and The Netherlands, demonstrating QKD in Europe for the first time. As ESA has said: “[Eagle-1] will allow the EU to prepare for a sovereign, autonomous cross-border quantum secure communications network.”
Eagle-1 is just the beginning, and is intended to serve as a prototype satellite for Europe’s ambitious, $97 million, flagship quantum program, the European Quantum Communication Infrastructure (EuroQCI). Launched in 2019, and akin to China and Canada, the pan-European program will eventually see a constellation of quantum satellites connected to a terrestrial fiber communication network spanning the entire European Union and overseas territories.
Cyrille Laborde, leader for quantum communications at Thales Alenia Space, is working on several EU projects developing QKD hardware that will feed into EuroQCI. Laborde is clear that Europe will demonstrate satellite-based QKD within the next few years. “A main challenge is to demonstrate that your quantum key distribution system is sufficiently secure, although given Micius demonstrated that in 2017, we don’t think this will be a showstopper,” he says.
“The satellites are a building block of a quantum network…and as soon as we have the fiber network in place, there will be no limits [to long-distance quantum communications],” he adds. “If quantum computing delivers what is expected of it, then [a global quantum network] will have a huge impact on everybody—this will be more important than classical computing was in the 1980s and ’90s.”
As these trailblazing quantum satellite programs unfold, myriad researchers have also been exploring how to use CubeSats—nanosatellites that typically weigh less than 10 kg—specifically to generate quantum keys. Such QKD-ready craft could link to form broad networks of satellites and augment larger satellites such as Micius, Jinan-1, QEYSSat, and Eagle-1.
Daniel Oi, and colleagues at the Centre for Quantum Technologies, National University of Singapore (NUS) have been working on this approach for more than a decade. As Oi puts it: “Big space, or traditional space engineering, is characterized by very long mission times and huge costs, so our idea was—how can quantum scientists cost-effectively gain the experience of putting things in space.”
This photon source, launched on the SpooQy1 CubeSat, creates entangled photons. Photo credit: Centre for Quantum Technologies, National University of Singapore.
As early as 2015, Oi and colleagues developed a compact photon source that generated quantum-correlated photon pairs aboard the Galassia CubeSat. Then, in 2019, entangled photon pairs were generated on the SpooQy-1 CubeSat—something that has previously only been demonstrated on Micius.
Since then, worldwide progress has been rapid. Only months ago, a CubeSat designed by Germany’s Center for Telematics, QUBE, launched on board a SpaceX rocket to generate quantum states of light pulses to test QKD on this smaller scale. And more QKD CubeSats, including SpeQtre, SPOQC, QUBE-II, QUICK³, SpeQtral-1, are set to follow. “With these CubeSats, [researchers] are really demonstrating that modestly-funded research teams can do something significant in the quantum space area,” says Oi.
A different way
So where does the US lie in the quantum space communication race? While the likes of NASA, the AFRL, and private sector organizations are exploring the necessary technologies, no quantum communications satellite launch date has emerged yet. Back in 2018 the Department of Energy unveiled a strategy to develop a national quantum internet with significant investment in ground-based quantum networks—that will eventually link to future quantum satellites—following. But the US is doing things differently.
As China, Canada, Europe, and other parts of the world, including South Korea, Japan, Singapore, and Russia, focus on QKD for quantum communications, the powers-that-be in the US—National Institute of Standards and Technology (NIST) and the National Security Agency (NSA)—are pursuing a different flavor of encryption; post-quantum cryptography (PQC). Unlike QKD, which exploits quantum physics to secure communications, PQC relies on quantum-resistant algorithms that are too complex for quantum computers to crack. Following nearly a decade of work with academic and industry partners including IBM, NIST cryptographers finalized standards for their first PQC algorithms in August 2024. They urge cybersecurity experts to use these to integrate PQC encryption into their systems now.
Dustin Moody, NIST mathematician and PQC Lead, who was instrumental in writing the standards, lists several reasons why the US prefers PQC. For starters, PQC can authenticate the source of a communications transmission by creating digital signatures, unlike QKD. “If you’re going to use QKD, you’re still going to have to use PQC to provide that functionality,” he says.
Moody also points out how PQC is more scalable, being deployable as software in classical computers, laptops, and mobile devices. In contrast, long-distance QKD will rely on novel hardware to extend entanglement over vast distances. And the NIST mathematician also questions if QKD’s theoretical security is actually fail-safe in practice. “Theoretically it [provides] perfect information security but you don’t have the same guarantee when it’s deployed,” he argues.
On the flipside, many point out that PQC users can face an incredibly steep learning curve given the algorithms’ complex mathematical constructs. Still, as Moody says: “You don’t need to choose one or the other—[QKD and PQC] certainly will co-exist for many people. There are hybrid techniques where you can put QKD into a PQC algorithm—and the security is great.”
But has the US made a risky choice, given other nations’ propensity for QKD? Ciel Qi, research analyst at the US-based Rhodium Group China practice, has been tracking quantum progress. She acknowledges the PQC benefits but believes the US should carefully monitor developments from China that may address QKD shortcomings. “If limitations were to be overcome, then the US may need to assess its need to invest in QKD as being more urgent,” she says.
The reasons for urgency run deep—it’s no secret that quantum communications technologies can be applied to civilian and military applications. “[We’re seeing] growing American concern about the dual-use nature of quantum technologies,” points out Qi. “The US government has added several Chinese quantum entities, including QuantumCTex, an organization Pan is affiliated with, to the Commerce Department’s export control list.”
“Moreover quantum communications is expected to be included in proposed US outbound investment rules that aim to regulate US investments in sensitive technologies abroad,” she adds. “This could lead to more restrictions on US-China academic collaboration.”
Still, at a time when Jian-Wei Pan has been elected a fellow of the Royal Society in London for contributions to quantum science, his work is clearly revered by researchers far and wide. Oi recalls how Micius “ignited” satellite-based quantum communications while Laborde comments: “When China is doing something in quantum communications, this is also good for Europe and the US.”
With QEYSSat set for launch, Kuntz reflects how the Micius success story showed that a quantum communication satellite wasn’t “pie in the sky” and made it easier for researchers to win grants. “You know, so much has been done by China’s researchers,” she says. “I think that we all admire what they’ve been doing—and it’s beautiful what they’ve accomplished.”
Rebecca Pool is a UK-based freelance writer