Orbital Data Centers: Spacecraft Constraints and Economic Viability

TL;DR

This paper evaluates the technical and economic feasibility of orbital data centers, deriving conditions for competitiveness based on power, mass, communication, and cost metrics, highlighting current launch cost challenges.

Contribution

It introduces a set of necessary conditions for orbital data center viability, integrating technical constraints with economic analysis, and compares them to current launch costs.

Findings

Orbital data centers require specific power, mass, and communication parameters to be feasible.

Current launch costs are significantly higher than the thresholds for economic viability.

Early regimes like edge compute are more credible than general terrestrial compute for orbital platforms.

Abstract

Orbital data centers are being evaluated as solar-powered compute constellations and relay-integrated processing platforms. Their feasibility is not set by orbital solar flux alone, but by simultaneous closure of photovoltaic generation, eclipse recharge, radiative heat rejection, sustained space-to-ground communications, utilization, replacement cadence, and delivered compute-years over finite mission life. This paper derives necessary cluster-level competitiveness conditions using delivered information-technology (IT) electrical power $P_{\rm IT}$, deployed mass per delivered IT power $m_{\rm kW}$ in kg/kW, communication intensity $\Gamma=D_{\rm sg}/E_{\rm IT}$, sustained communication ceiling $\Gamma_{\max}$, effective utilization $U_{\rm eff}$, and lifetime penalty $\Pi_{\rm life}$. For a representative $P_{\rm IT}$=1 MW high-sunlight anchor, the base case gives beginning-of-life photovoltaic area $A^{\rm BOL}_{\rm PV}=5.64 \times 10^3 {\rm m}^2$, radiator area $A_{\rm rad}=2.50 \times 10^3 {\rm m^2}$, and 29.4 kg/kW for photovoltaic, storage, and radiator mass; fixed spacecraft mass raises the total to 34-59 kg/kW. At m_kW ~ 40 kg/kW, a terrestrial infrastructure benchmark of 10-40 k\$/kW allows only 250-1000 \$/kg for the combined launch and spacecraft-build cost before space-to-ground communications, operations, utilization, and lifetime terms are included. That allowance is 3.4-13.5 times below the current public Falcon 9 dedicated low-Earth-orbit launch-price benchmark alone, before spacecraft build is included. Space-native preprocessing and communications-integrated edge compute are credible early regimes; terrestrial-user general compute closes only for low Earth-coupled communication intensity, high effective utilization, long delivered lifetime, and very low combined launch-plus-build cost.