2026/04/29 by Slava G. Turyshev · 2 voices
Engineering · Physics and Astronomy · #eess.SY #physics.gen-ph
paper · pdf · doi:10.48550/arxiv.2604.27197
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 Γ=D\rm sg/E\rm IT, sustained communication ceiling Γmax, effective utilization U\rm eff, and lifetime penalty Π\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 × 103 \rm m2, radiator area A\rm rad=2.50 × 103 \rm m2, and 29.4 kg/kW for photovoltaic, storage, and radiator mass; fixed spacecraft mass raises the total to 34-59 kg/kW. At mkW ~ 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.