Novel Use of Photovoltaics for Backup Spacecraft Laser Communication System

TL;DR

This paper proposes a novel backup laser communication system for spacecraft using photovoltaics as receivers, aiming to address spectrum licensing issues and improve emergency contact capabilities.

Contribution

It introduces a new concept of photovoltaic-based laser communication for spacecraft, including laboratory feasibility analysis and a preliminary CubeSat demonstrator design.

Findings

Laboratory experiments verify the photovoltaic laser reception concept.

Preliminary CubeSat design demonstrates potential for real-world application.

The system offers an alternative to RF communication for emergency scenarios.

Abstract

Communication with a spacecraft is typically performed using Radio Frequency (RF). RF is a well-established and well-regulated technology that enables communication over long distances as proven by the Voyager 1 & II missions. However, RF requires licensing of very limited radio spectrum and this poses a challenge in the future, particularly with spectrum time-sharing. This is of a concern for emergency communication when it is of utmost urgency to contact the spacecraft and maintain contact, particularly when there is a major mission anomaly or loss of contact. For these applications, we propose a backup laser communication system where a laser is beamed towards a satellite and the onboard photovoltaics acts as a laser receiver. This approach enables a laser ground station to broadcast commands to the spacecraft in times of emergency. Adding an actuated reflector to the laser receiver on the spacecraft enables two-way communication between ground and the spacecraft, but without the laser being located on the spacecraft. In this paper, we analyze the feasibility of the concept in the laboratory and develop a benchtop experiment to verify the concept. We have also developed a preliminary design for a 6U CubeSat-based demonstrator to evaluate technology merits