Space Mirrors
& Astronomy
Every major astronomical organisation in the world has formally opposed space mirror constellations. This page compiles the science: contamination rates by telescope, astronomer quotes, the organisations who filed FCC objections, and what the peer-reviewed research says.
Every Major Organisation Has Filed Objections
The opposition to space mirror constellations is not a fringe position — it represents the unified view of the global professional astronomy community. Every major astronomical society has either filed formal FCC comments, issued public statements, or both. This is unusual. Astronomers rarely speak with one voice; the scale of the concern here is a signal in itself.
Peer-Reviewed Impact Projections
In December 2025, NASA Ames Research Center scientist Dr. Alejandro S. Borlaff, with co-authors Pamela M. Marcum and Steve B. Howell, published a peer-reviewed study in Nature modelling the impact of proposed satellite constellations on both ground-based and space-based telescopes. The study modelled a scenario of approximately 56,000 satellites — the total projected by end of decade from all approved constellations at time of publication, before the SpaceX million-satellite proposal. The results were described by researchers as "staggering."
| TELESCOPE | IMAGES AFFECTED | VERDICT |
|---|---|---|
| Hubble — baseline (2021) | ~4% | Manageable |
| VLT — ESO, Chile | Up to 10% | Significant loss |
| Hubble — at 56k sats | ~33–40% | Severe degradation |
| SPHEREx — NASA | ~96% | Effectively unusable |
| ARRAKIHS — ESA | ~96% | Effectively unusable |
| Xuntian (CSST) — China | ~96% | Effectively unusable |
| Vera C. Rubin | Continuous | Survey mission broken |
Source: Borlaff, Marcum & Howell, Nature Dec 2025 · Based on ~56,000 approved satellites · SpaceX 1M-satellite proposal filed Jan 2026 would increase these figures substantially
In Their Own Words
A Qualitatively Different Problem
Regular satellites like Starlink are bright but passive — they reflect ambient sunlight. The astronomical community has spent years developing algorithms to mask satellite trails in images. It's imperfect but it works at low contamination rates.
Space mirrors are a fundamentally different problem for three reasons. First, they are actively directed — the mirror is pointed deliberately at a target on Earth, concentrating sunlight rather than passively reflecting it. When a mirror passes over an observatory, the concentrated beam is orders of magnitude brighter than a passive satellite. Second, the mirrors orbit along the day-night terminator, meaning they are illuminated and directing light during astronomical twilight and darkness — exactly when observatories are working. Third, at full constellation scale the mirrors would raise the background brightness of the entire night sky by an estimated 3-4× according to the RAS, permanently degrading the signal-to-noise ratio of every ground-based telescope on Earth.
The Borlaff et al. study authors explicitly compared the situation to the early period of industrial CFC use before the ozone crisis — a slow-building catastrophe that was structurally invisible until it became undeniable.
The Vera C. Rubin Observatory in Chile is specifically designed to survey the entire sky repeatedly, creating a time-lapse of the universe. Its 3.2 gigapixel camera captures a 9.6 square degree field — a significant fraction of the night sky per exposure. This survey design makes it uniquely vulnerable: it cannot simply avoid satellite-contaminated parts of the sky, because its scientific mission requires repeated observations of every part of the sky. Satellites that would appear in only occasional images for a pointed telescope appear in essentially every Rubin image of any given sky region over time. The Rubin Observatory cost $473 million to build.
The Limits of Technical Fixes
Software masking: Algorithms can identify and remove satellite trails from images. This works when contamination is low. At 40–96% contamination it becomes impossible — you cannot recover data from behind a satellite trail, and at high contamination rates the masked data gaps exceed the usable data.
Scheduling around passes: Observatories can, in principle, schedule observations to avoid known satellite positions. This requires precise orbital data for all satellites (often not publicly available), sophisticated scheduling software, and acceptance of significant lost observing time. For a million-satellite constellation this becomes computationally intractable.
Darker satellite coatings: SpaceX applied a "VisorSat" dark coating to Starlink satellites after astronomical objection. This reduced but did not eliminate visibility. Reflect Orbital's mirrors are, by design, maximally reflective — a dark coating defeats their entire purpose.
Observatory exclusion zones: Reflect Orbital has proposed avoiding major telescope sites during operations. This is operationally feasible for the demonstration satellite but becomes logistically complex at 50,000 satellites. It also only addresses the direct beam impact — not the background sky brightness increase from thousands of mirrors in orbit simultaneously.
The scientific consensus is that none of these mitigations are adequate at the proposed constellation scales. The AAS's formal position is that the potential for catastrophic interference with federally funded astronomical research outweighs the experimental utility of the Earendil-1 demonstration mission.
What Was Filed and When
The FCC comment period for Reflect Orbital's application (SAT-LOA-20250701-00129) closed on 9 March 2026 with over 1,800 comments — an exceptionally high number for a single-satellite demonstration mission. The AAS filed a formal petition to deny. DarkSky International published a technical hazard analysis classifying Earendil-1 as a Risk Group 3 (High Risk) light source. The RAS, IAU, and ESO all submitted formal comments. The FCC is legally required to consider all of this material before making its decision.
This volume and quality of scientific objection is historically unusual. The FCC has historically granted commercial satellite licences without conducting environmental impact assessments, using a "categorical exclusion" that presumes satellites have no significant environmental impact. Astronomers argue this exclusion is inadequate for mirror constellations that deliberately and actively direct concentrated sunlight at the Earth's surface.