In 2023, Heriot-Watt University took its first major step towards creating a ‘space cluster’ at its Edinburgh campus with approval by the local council to construct an optical ground station on the University Research Park. Due to be completed in Autumn 2024 the facility will:

• conduct research
• support innovation and space sustainability
• enhance teaching at the university.

Led by the Quantum Communications Hub and funded by the Engineering and Physical Science Research Council (EPSRC) through the UK National Quantum Technologies Programme (NQTP). The project is a testament to the Science and Technology Facilities Council’s Rutherford Appleton Laboratory and the collaborative efforts of the Universities of:

• Bristol
• Heriot-Watt
• Strathclyde
• York

Dr Ross Donaldson, Co-Lead of the Quantum Communications Hub Optical Ground Station (HOGS) at Heriot-Watt University explains.

The HOGS Facility

The HOGS facility site is a secure 256 m² area on the Heriot-Watt University Research Park of the Edinburgh campus. It aims to demonstrate UK academic capabilities in satellite quantum secure communications and strengthen the UK’s place as a global leader in quantum technology research. On site we have:

• a self-contained “operations centre” modular building to house the operations and visiting research teams.
• an optical ground station comprising a 4.5m in diameter clamshell-style observatory dome.
• a 70cm diameter optical terminal, which is a Nasmyth observatory telescope with two 100kg ground payload capabilities.
• a 40cm piggyback telescope with an 850nm uplink optical beacon and visible and infrared cameras for coarse tracking. That piggyback is attached to the main telescope with a robotic mount, allowing us to compensate for the flex and movement of the piggyback when the telescope mount moves.
• an environmental monitoring tool to measure local environmental conditions, including atmospheric turbulence, to validate system performance and verify modelling.

On the main telescope we can place equipment including:

• a deformable mirror adaptive optics system with a choice of a visible or infrared wavefront sensor.
• fine steering mirrors and tracking sensors.
• single-photon detection with silicon single-photon detectors or superconducting nanowire detectors (both array and single-pixel detectors).

Link ups

The HOGS site links to a “local dark optical-fibre network”, connecting the HOGS site with local academic buildings and a lab-based network simulator. The academic buildings provide access to “next-generation” quantum and photonic systems, such as quantum memories, superconducting nanowire detectors, and entangled photons, essential for research into quantum networking. The network simulator, made of packaged optical fibre reels, provides access to point-to-point links from 10 to 300 km.

But HOGS is not just a standalone project, it’s a crucial part of a major investment into a scientific quantum satellite communications mission, Satellite Platform for Optical Quantum Communications (SPOQC) to be launched in 2025.

Delivering satellite quantum communications

The SPOQC mission will contain a quantum communication payload(s) that will downlink to HOGS and other optical ground stations in the UK and around the globe. Enabling us to create a globally scaling quantum communications network. 

The Hub’s in-orbit demonstrator is one of two complementary satellite quantum communications research projects currently undertaken by UK organisations and the National Quantum Technologies Programme.

The other is the UK/Singapore bilateral mission (project Speqtre), which also has its own dedicated optical ground station based at STFC Chilbolton. HOGS was funded to be the central downlink node within the UK for the SPOQC mission.

Beyond those two missions, there are already other satellite quantum communications missions being developed by UK teams, as well as missions led by different countries that involve UK teams. We are already looking to use HOGS for all those further missions.

Enhancing capabilities

After the initial investment in the HOGS equipment and the inclusion of the Heriot-Watt University team in other satellite missions, an EPSRC Strategic Equipment Grant and continued investment in the Hub programme provided further funding to enhance capabilities, with additional equipment and support infrastructure.

In addition to enabling us to support future satellite quantum communication missions, the new equipment broadens the remit of HOGS facilitating support for:

• new research
• innovation activities
• space sustainability
• enhanced teaching activities on the campus.

HOGS’ extensive site equipment and local infrastructure set it as a critical infrastructure facility for satellite quantum communications for the UK. Still, the capabilities also lend themselves to many other fields.

Capabilities for multiple fields

For example, in optical communications, we seek to engage with current and future missions exploring high bandwidth capabilities. Whilst in space situational awareness, our latitude gives us great visibility of satellites, debris, and junk in low-earth polar orbit. We are exploring the site’s utilisation to aid in efforts to track and eventually de-orbit debris and junk, helping make space a more sustainable place.

Academics at the university already engage in “astro-photonics,” a field of research seeking to improve astronomical measurements utilising new and novel photonic devices; the local and large telescope systems will aid in testing devices before installation on much larger telescopes.

Beyond academic research, the UK aspires to lead innovation in quantum, photonics, and space. The HOGS facility helps in this journey by providing research facilities essential to demonstration and validation.

Future ambitions

The timing of the HOGS development aligned well with other initiatives on the Heriot-Watt University campus. Ambitions like creating “innovation space” on the university research park and starting a new undergraduate teaching programme in aerospace engineering in 2023.

There are future ambitions to create and connect HOGS to a “Scottish Quantum Network”. This would connect Universities and business centres across the Central Belt of Scotland. HOGS would provide the essential Scottish network node needed to connect to satellites that would link to the UK Quantum Network (an optical fibre network in the South of England) and to other global networks with a satellite connecting node.

The research park's ambitions include:

• using current buildings to host teams
• the creation of a new building to create incubation spaces with laboratories.
• enhancing skills and training for the new aerospace and established engineering programmes (mechanical and electrical engineering as well as physics), offering projects for student dissertations and contributions to teaching courses.

Visit us in Hall 4 on stand 4710 to find out more.

Author – Dr Ross Donaldson, Contact – [email protected]