Quantum Physics explains the nature and behaviour of matter and energy on the atomic and subatomic levels. This branch of physics is supposed to be the most complicated. The applications of quantum physics are predicted to bring major changes in the human lifestyle in near future. The meaning of the word quantum indicates that it is the smallest possible discrete unit of any physical property, for instance, energy or matter. To understand the nuances of quantum physics, there is a need to appreciate complex concepts such as entanglement and superposition. However, some applications of quantum technologies are straightforward and there is no need to get into the intricate details of science for appreciating the forte of quantum technology.

At present, there are mainly four types of technological applications in the quantum field, which are under debate. They include quantum computing, quantum communications, and quantum sensing and quantum simulations. Also, research is underway in fields such as quantum metrology (the science of measurement) and quantum internet. Outer space is another domain where some interesting research and innovation are happening. It is important to appreciate that in the space sector, various other applications of quantum technologies are finding much utility. Realising the need to quickly encash the advantages in the domain of quantum space, some countries including the US and China have already begun investing in these fields. In 2019, the European Union came out with a white paper discussing the applicability of quantum sciences in the domain of space, particularly focusing on the growth of patent filing. This report has been prepared by the European Patent Office and the European Space Policy Institute (ESPI) in collaboration with the European Space Agency (ESA).

Quantum technologies in space are mainly relevant in the arena of secure communications. There is a good amount of work happening in the field of Quantum Key Distribution (QKD), Cold Atom Clocks and Cold Atom Interferometers. QKD is the most popular mechanism to develop secure communication. It is all about cryptography, a method of ensuring secure (un-hackable) communications. Secure communications are vital both for the defence and strategic agencies and also for various civilian organisations. While atomic clocks with cold atoms are valuable in the arena of fundamental physics. Such clocks in space allow the investigation of aspects such as dark matter and general relativity. These clocks are important from the point of view of deciding on the most precise and accurate frequency standards, while Cold Atom Interferometers have the potential to transform sectors such as navigation and positioning, resource exploration, geophysical studies, and fundamental physics.

Now, in various cases, sensitive data is found getting encrypted and then sent across fiber-optic cables and other channels along with the required digital keys needed to decode the information. The data and the keys are sent as classical bits via the famously known format of 0s and 1s. However, this format is vulnerable to hacking. This is where Quantum Communications come into play. Here multiple combinations of 0s and 1s, happen simultaneously. These quantum bits (qubits) cannot be tampered with by the hackers without leaving behind a tell-tale sign of the activity. As of date, this technology is not fully matured and needs more research. Significantly, some private corporations have been engaged with the properties of quantum physics to create networks for transmitting highly sensitive data based on QKD.

Second revolution

In the first quantum revolution, which is said to have begun during the 20^th century, a basic understanding of various facets of quantum sciences and their applications was worked on. Interestingly, the research in this area was not restricted to any one agency and simultaneous research was conducted in universities, government laboratories, defence agencies and private institutions.  At present, the second quantum revolution is underway and space is one sector in which research is on in the various quantum research agencies. Particularly, the EU is found spearheading the research in this field. Various agencies supported by them are found promoting the development of quantum technologies for space applications in the fields of secure communication, time and frequency services, Earth sensing and observation and quantum computing for space data processing and mission planning.

Europe’s technological leadership opines that in order to protect (from a long-term perspective) their sensitive data and digital infrastructure investments in quantum communications are a must. For this purpose, they have signed an agreement (2019) with the European Space Agency (ESA) to prepare a secure end-to-end quantum communication infrastructure.  Such a setup is expected to have utility beyond the field of cybersecurity. The applicability could be there in fields like digital signatures, authentication, and clock synchronisation. The broad and long-term aim is to develop Europe’s Quantum Internet. Such a network could help link quantum computers, simulators and sensors to distribute information and make aware (and available) quantum resources. In this connection, all EU member states have signed the European Quantum Communication Infrastructure (EuroQCI) Declaration.

Asian players

There are a few Asian countries such as Japan, Israel and India that are taking much interest in the field of juxtaposing quantum and space applications. However, the main Asian player in this field is China, which has identified quantum communications as one of the major S & T projects reflecting their national strategic intent and plans to complete this project by 2030.

In the quantum field, notable Chinese success has been with the Quantum Experiments at Space Scale (QUESS), a US$100 million research project. The first satellite in the QUESS fleet, Micius (or known as Mozi, who was a Chinese philosopher and scientist in the 5th century BC) with a quantum optical payload, was positioned in a sun-synchronous orbit during August 2016. QUESS is a combined Chinese-Austrian satellite mission operated by CAS (Chinese Academy of Sciences), in cooperation with the University of Vienna and the Austrian Academy of Sciences (AAS). QUESS has been a mission designed to enable quantum optics experiments over long distances to allow the advance of quantum encryption and quantum teleportation technology. The first experiment China conducted after launching the satellite involved sending of a laser beam into a light-altering crystal on the satellite. Subsequently, various experiments involving QKD have been carried out and China has been successful towards transmitting the data between two stations separated by a distance of more than 7500 km on Earth. All of this could be seen as the preliminary groundwork towards building a hack-proof global quantum communication network. China plans to replace the Micius satellite with a more advanced quantum satellite in the near future.

Apart from quantum commutations in which the work is on in the EU and China, very interesting work is happening in the area of the atomic clock in other parts of the world. Such clocks have employability in the Global Navigation Satellite System (GNSS). These technologies are also expected to change the face of global satellite-based navigation in near future.

The ongoing discussion indicates that the use of quantum technologies in the space arena is fast becoming a reality. There is an increasing focus on connecting quantum technologies and space applications since such efforts are expected to bring in a revolution towards achieving secured communication and making space-based navigation more accurate. It is expected that in the coming years, more concrete applications would emerge, which would change the face of the digital era.

-The author is a Security Analyst based at New Delhi. The views expressed are of the author and do not necessarily reflect the views of Raksha Anirveda