HRL Laboratories and Boeing have completed construction and validation of a fully integrated quantum communication subassembly for Boeing’s Q4S satellite mission, which aims to demonstrate four-photon quantum entanglement swapping in orbit. The subassembly includes an optical board, control electronics, and thermo-mechanical packaging in a 15 kg, space-qualified payload. It is currently undergoing end-to-end software verification and environmental testing at Boeing’s El Segundo Space Simulation Laboratory. The validated system will serve as the ground twin for the on-orbit payload currently in production.
The Q4S mission is designed to demonstrate entanglement swapping, a process that enables the entanglement of previously unconnected nodes—key to realizing future distributed quantum networks and secure quantum communication in space. HRL confirmed quantum entanglement from each of the two single-photon sources in the assembly, detecting over 2,500 matching photon pairs per second with measured fidelities between 0.8 and 0.9. These results meet the mission’s quantum measurement requirements and validate system readiness for orbital deployment.
This milestone follows Boeing’s earlier announcement of the Q4S project, which is among the first missions to attempt quantum entanglement swapping in space. The successful validation of the subassembly represents a major step toward achieving scalable, space-based quantum communication infrastructure.
Read the full press release from Boeing and HRL Laboratories here and read our previous coverage of the Q4S mission here.
April 16, 2025
Leave A Comment