Electrical engineering

Physics

Aerospace engineering

Topology (electrical circuits)

Key (lock)

Constellation

Operating system

Software deployment

Astronomy

Engineering

Satellite

Geography

CubeSat

Computer science

Quantum mechanics

Quantum key distribution

Spacecraft

Computer security

Environmental science

Remote sensing

Telecommunications

Quantum

Cryptography

Quantum key distribution (QKD) offers future proof security based on fundamental laws of physics. Long-distance QKD spanning regions such as the United Kingdom (UK) may employ a constellation of satellites. Small satellites, CubeSats in particular, in low Earth orbit are a relatively low-cost alternative to traditional, large platforms. They allow the deployment of a large number of spacecrafts, ensuring greater coverage and mitigating some of the risk associated with availability due to cloud cover. We present our mission analysis showing how a constellation comprising 15 low-cost 6U CubeSats can be used to form a secure communication backbone for ground-based and metropolitan networks across the UK. We have estimated the monthly key rates at 43 sites across the UK, incorporating local meteorological data, atmospheric channel modelling and orbital parameters. We have optimized the constellation topology for rapid revisit and thus low-latency key distribution.

QUARC: Quantum Research Cubesat—A Constellation for Quantum Communication