Power consumption is a critical constraint for CubeSat based quantum communication, where tracking systems often dominate the onboard power budget. We demonstrate an energy-efficient approach that enables reliable satellite tracking at substantially reduced beacon power by treating tracking as a weak-signal estimation task. Using a closed-loop system with fine steering mirrors and higher-order Kalman filters on ground, we can maintain stable tracking at a transmitted power equivalent to 34 mW over a -60 dB satellite to ground optical channel. Our results show that the resulting penalties on QKD bit error rates and signal-to-noise ratios are negligible, allowing for more efficient power allocation to quantum payloads in CubeSat missions.
Cite
@article{arxiv.2602.22160,
title = {Energy efficient optical tracking for space quantum communication},
author = {Eric Vokes and Vinod N. Rao and Elinore Spencer and Rupesh Kumar},
journal= {arXiv preprint arXiv:2602.22160},
year = {2026}
}