The new satellite constellation proposed by SpaceX aims to power AI computational centers providing an annual amount of energy of order of 1000 TWh; this substantial amount would be obtained from solar energy captured in space. This goal is achieved by requiring the production of 100 GW of power available for computation from a system of satellites that would necessarily have a total collecting area of solar panels of at least 100 km2. In practical terms, these requirements with the current technology translate into operating of the order of 1 million satellites each weighing about 1 ton and with solar panels of several hundred square meters. The unprecedented scale of the project in terms of number and characteristics of the satellites poses several serious challenges to the near-Earth space environment. The project would drastically alter the Low Earth Orbit (LEO) satellite ecosystem, and would have severe consequences for scientific observations, especially for Astronomy. The considerations provided here apply to the specific SpaceX project under review by FCC but have general validity.
The Accademia Nazionale dei Lincei:
• Expresses grave concern about the proposed Orbital Data Centers (ODCs).
• Notes that for the proposed 30 degree inclination belt and sun-synchronous high inclination orbits, assuming reflectivities similar to those of SpaceX satellites, the ODC satellites are expected to drastically affect the sky. Depending on the season and night time, the number of Sun-reflecting ODC satellites would outnumber that of visible stars causing a severe change in the human perception of the night sky. Even adopting the current mitigation measures regarding satellite reflectivities as recently implemented by SpaceX (as a result of an ongoing dialog with astronomical institutions), the ODC satellites would very negatively affect astronomical optical observations on the ground.
• Further notes that radiative cooling of ODC satellites, of which no detail is provided by SpaceX, would produce widespread infrared and submillimeter spurious sources that would hamper astronomical observations.
• Further notes that satellite radio communication in the frequency window of a few tens of GHz and satellite electromagnetic “noise” at lower frequencies would drastically affect radiotelescopes’ observations.
• Emphasizes the risk of accidental collisions and/or failures of the alleged autonomous on-board system for satellite avoidance, a situation that would create an uncontrolled number of space debris.
• Further notes that scientific LEO satellites crucial for Earth monitoring and astronomical research would be subject to interference and collisions with ODC satellites.
• Emphasizes that launching in LEO orbits of the order of a million tons per year, as considered by SpaceX, would deposit million tons per year of fuel (mostly kerosene and methane) in the stratosphere and mesosphere with significant environmental consequences.
• Further notes that launching, operating, deorbiting/disposal, and even partial replenishing of a 1 million satellite constellation constitutes a formidable technological challenge with many technical aspects not currently specified.
• Further expresses concern about the unspecified use of the requested many waivers that could avoid normal checks on the placement of the satellite ODC system into orbit.
Attached please find a pdf document