Are space-based data centers a key to decarbonizing the digital sector?

Commissioned by the European Commission as part of the ASCEND project, which brought together a consortium of stakeholders ^[1] Under the leadership of Thales Alenia Space, Carbone 4 conducted a feasibility study aimed at determining the technical conditions under which the “space data center” (SDC) scenario could be more carbon-efficient than the “ground-based data center” (TDC) option.

What is a “Space Data Center”?

The "Space Data Center" (SDC) concept proposes placing data centers in orbit around Earth, powered by photovoltaic panels, similar to satellites.

To outperform terrestrial data centers (“TDCs”) in terms of carbon footprint, the SDC assumes a higher load factor for solar panels in orbit compared to those on Earth, and optimized heat dissipation to manage the heat generated by the data centers.

To limit emissions, the launch into orbit would be carried out using environmentally optimized (e.g., with low-carbon propellants) and reusable launch vehicles.

The Results of the Carbone 4 Study

The first part of the prospective study initially made it possible to assess that More than 70% of the SDC's carbon footprint is reportedly attributable to the deployment of data centers into orbit (covering emissions related to the production of launch vehicles, the production of propellants, and emissions generated during rocket launch).

Below are the detailed results:

The second part of the study found that the carbon benefit of the SDC (compared to the TDC) was subject to a a real feat on the part of the European space sector, particularly in order to successfully develop the launch vehicle the world's lowest-carbon. In fact, in order to significantly reduce CO2 emissions from the storage and processing of digital data, the study’s findings suggest that such space-based infrastructure would require the development of a launch vehicle whose carbon intensity per kilogram of payload would be reduced by a factor of ten throughout its entire life cycle.

Project Scope

Finally, the last part of our study focused on highlighting several limitations surrounding the results of our research, which are important to note:

• The study does not take into account emissions into the upper atmosphere, and in particular the warming dynamics between the stratosphere and the troposphere
• The study was unable to investigate the possible rebound effects of SDC, and in particular the increase in data usage that this technology could drive by making data more accessible
• Nor did the study examine any potential spillover effects associated with the development of a heavy-lift launch vehicle, particularly the increase in the volume of payload placed into orbit that such a launch vehicle could bring about in the long term
• There is also some uncertainty regarding the environmental footprint of mineral raw materials (copper, nickel, cobalt, rare earth elements, etc.) needed for the SDC

It is important to remember, however, that such a project must not overshadow a fundamental principle for the smooth progress of the transition: that of simplicity. Furthermore, this project will only be relevant if it focuses on ensuring data exchange necessary and critical for human societies, rather than whether it aims to replicate in space all the digital applications currently in use. Indeed, beyond climate change, it is the overall environmental footprint—including water and air pollution and impacts on biodiversity—of the space and digital sectors that we must examine (and reduce!) through such a project.

For more information:

• Visit the project's official website: https://ascend-horizon.eu/
• Read the consortium's press release: https://www.thalesaleniaspace.com/en/press-releases/thales-alenia-space-reveals-results-ascend-feasibility-study-space-data-centers-0