Progress on ELROI satellite license plate flight prototypes

TL;DR

This paper discusses the development and testing of ELROI, a low-resource optical beacon for satellite identification, including prototype design, validation, and plans for orbital deployment to enable ground-based ID retrieval.

Contribution

It introduces the ELROI satellite beacon concept, details the design and testing of prototypes, and discusses integration into CubeSats for orbital deployment.

Findings

Validated ELROI prototypes in ground tests

Designed a compact PC-104 form factor unit

Scheduled orbital launches for 2018 and beyond

Abstract

The Extremely Low-Resource Optical Identifier (ELROI) beacon is a concept for a milliwatt optical "license plate" that can provide unique ID numbers for everything that goes into space. Using photon counting to enable extreme background rejection in real time, the ID number can be uniquely identified from the ground in a few minutes, even if the ground station detects only a few photons per second. The ELROI concept has been validated in long-range ground tests, and orbital prototypes are scheduled for launch in 2018 and beyond. We discuss the design and signal characteristics of these prototypes, including a PC-104 form factor unit which was integrated into a CubeSat and is currently scheduled to launch in May 2018, and basic requirements on ground stations for observing them. We encourage others to consider observing our test flights.