ELROI: A License Plate For Your Satellite

TL;DR

ELROI is a compact, low-power optical beacon that provides a persistent, autonomous identification signal for space objects, simplifying tracking and identification without interfering with operations.

Contribution

The paper introduces ELROI, a novel milliwatt-scale optical license plate for satellites that requires no power or control from the host and is suitable for small space objects.

Findings

Validated with ground tests

Designed for small satellites like CubeSats

First flight test scheduled for 2018

Abstract

Space object identification is vital for operating spacecraft, space traffic control, and space situational awareness, but initial determination, maintenance, and recovery of identity are all difficult, expensive, and error-prone, especially for small objects like CubeSats. Attaching a beacon or license plate with a unique identification number to a space object before launch would greatly simplify the task, but radio beacons are power-hungry and can cause interference. This paper describes a new concept for a satellite license plate, the Extremely Low Resource Optical Identifier or ELROI. ELROI is a milliwatt-scale self-powered autonomous optical beacon that can be attached to any space object to transmit a persistent identification signal to ground stations. A system appropriate for a LEO CubeSat or other small space object can fit in a package with the area of a postage stamp and a few millimeters thick, and requires no power, data, or control from the host object. The concept has been validated with ground tests, and the first flight test unit is scheduled for launch in 2018. The unique identification number of a LEO satellite can be determined unambiguously in a single orbital pass over a low-cost ground station.