Dirty Bits in Low-Earth Orbit: The Carbon Footprint of Launching Computers
Abstract
Low-Earth Orbit (LEO) satellites are increasingly proposed for communication and in-orbit computing, achieving low-latency global services. However, their sustainability remains largely unexamined. This paper investigates the carbon footprint of computing in space, focusing on lifecycle emissions from launch over orbital operation to re-entry. We present ESpaS, a lightweight tool for estimating carbon intensities across CPU usage, memory, and networking in orbital vs. terrestrial settings. Three worked examples compare (i) launch technologies (state-of-the-art rocket vs. potential next generation), (ii) operational emissions of data center workloads in orbit and on the ground and, (iii) in-orbit aggregation with raw data transmission. Results show that, even under optimistic assumptions, in-orbit systems incur significantly higher carbon costs - primarily due to embodied emissions from launch and re-entry. Our findings advocate for carbon-aware design principles and regulatory oversight in developing sustainable digital infrastructure in orbit.
Keywords
Cite
@article{arxiv.2508.06250,
title = {Dirty Bits in Low-Earth Orbit: The Carbon Footprint of Launching Computers},
author = {Robin Ohs and Gregory F. Stock and Andreas Schmidt and Juan A. Fraire and Holger Hermanns},
journal= {arXiv preprint arXiv:2508.06250},
year = {2026}
}
Comments
This is the authors' version of a paper that was originally presented at the 4th Workshop on Sustainable Computer Systems (HotCarbon'25) and subsequently published in the ACM SIGENERGY Energy Informatics Review, see https://doi.org/10.1145/3757892.3757896. v2 fixes incomplete author affiliations; v3 fixes incorrect use of constants relating to chemical effects (greenhouse warming potential)