A California-based startup has unveiled an ambitious and controversial plan to deploy a vast constellation of orbiting mirrors, designed to reflect sunlight onto solar farms long after sunset. The company, Reflect Orbital, aims to solve the fundamental problem of solar power’s intermittency by creating “sunlight on demand,” potentially allowing solar panels to generate electricity through the night. Proponents see it as a way to bolster clean energy production, but the proposal has sparked widespread alarm among astronomers and environmental scientists, who warn of unprecedented light pollution and severe ecological disruption.
The core of the proposal is to transform the night sky into a resource for energy generation. By strategically positioning thousands of satellites in orbit, the company intends to illuminate solar energy facilities for extra hours, bridging the gap between daytime generation and nighttime demand. However, this would be achieved by design, creating what many experts consider a new and dangerous form of light pollution. The project’s feasibility, scalability, and potential impact on science and nature are now at the center of a growing global debate, pitting the quest for renewable energy against the preservation of the natural night.
The Technology of Reflected Sunlight
Reflect Orbital’s plan relies on a large-scale satellite constellation to function as a system of space-based mirrors. The company has applied for permission from the U.S. Federal Communications Commission (FCC) to launch an initial 18-meter experimental satellite, named Earendil-1, in 2026. This test satellite is intended to be the first of many. The company’s roadmap suggests a goal of deploying approximately 4,000 satellites by 2030, with some company projections suggesting an ultimate fleet of up to 250,000 satellites. These spacecraft would orbit at an altitude of about 625 kilometers, each equipped with large, 54-meter-wide mirrors to capture and redirect solar rays.
The physics behind the concept are straightforward, similar to bouncing light off a watch face to create a bright spot on a wall. However, the scale of the operation introduces significant challenges. Because the Sun is not a single point of light in the sky, a beam of sunlight reflected over the vast distance from orbit will inevitably spread out. Calculations show that even from a 625-kilometer orbit, the reflected light would illuminate a patch of ground at least 7 kilometers across. The goal is to deliver an intensity of about 200 watts per square meter, which is roughly 20% of the strength of the midday Sun. While this is 15,000 times dimmer than direct sunlight, it would still be significantly brighter than a full moon.
An Ambitious Energy Solution
Addressing Solar’s Intermittency
The fundamental problem Reflect Orbital aims to solve is the inability of solar farms to generate power at night. Founder Ben Nowack has stated that solar power is an “unstoppable force” for powering humanity, but its primary limitation is that the sunlight “turns off.” By providing illumination after dark, the company hopes to “fix solar everywhere” and allow these facilities to continue producing valuable energy during peak evening demand hours. This would transform solar power from an intermittent daytime source into a more reliable and consistent contributor to the energy grid, reducing reliance on fossil fuels or battery storage during nighttime hours.
Scaling the Constellation
Achieving this vision would require a celestial operation of unprecedented scale. A single satellite, moving at 7.5 kilometers per second, would only be able to illuminate a given location for about 3.5 minutes as it passes overhead. Therefore, maintaining continuous illumination on even one solar farm would require a constant stream of satellites passing over it. Experts estimate it could take around 3,000 satellites working in concert to provide a beam at 20% of midday strength for a single region. Providing this power for just one hour would necessitate thousands more. This operational complexity explains the enormous number of satellites proposed in the company’s long-term vision; the 250,000-satellite figure suggested by Nowack would exceed the total number of all active satellites and tracked space debris currently in orbit.
Widespread Scientific Concerns
Light Pollution and Astronomy
The scientific community, particularly astronomers, has reacted with alarm to the prospect of intentionally illuminating the night sky. Unlike the stray reflections from existing satellites, which are an unfortunate byproduct, Reflect Orbital’s system is expressly designed to create light pollution. Anthony Tyson, the science director at the Rubin Observatory, warned that the reflected light could interfere with the sensitive cameras used in modern telescopes, disrupting research that depends on dark skies. His concerns are widely shared. An August 2025 survey by the American Astronomical Society found that over 1,400 scientists believed their work would be negatively impacted by the project.
Ecological and Health Impacts
Beyond astronomy, the potential environmental consequences are also a major point of concern. Meredith Rawls, an astronomer at the University of Washington, has warned that introducing artificial sunlight at night could disturb nocturnal species, including moths, frogs, and bats, with cascading negative effects on the ecosystem. Constant, large-scale illumination would disrupt the natural cycles of light and dark that countless organisms rely on for navigation, hunting, and reproduction. Furthermore, a growing body of research has linked light pollution to negative health effects in humans, disrupting sleep patterns and contributing to other health issues.
Feasibility and Future Outlook
Regulatory and Financial Hurdles
While the project’s ambitions are clear, its path forward is not. The first major step is securing regulatory approval, starting with the FCC application for the Earendil-1 test launch. The project has attracted significant financial backing from investors, including Sequoia Capital and tech billionaire Baiju Bhatt, indicating confidence in its commercial potential. However, scaling from a single test satellite to a quarter-million is a monumental leap that will require overcoming immense logistical, technical, and financial challenges, in addition to navigating a complex and likely contentious regulatory environment worldwide.
Company’s Response and Projections
In response to the criticism, Reflect Orbital has stated that it will conduct environmental impact assessments and collaborate with local communities where its services are deployed. The company also claims that the carbon emissions generated by its satellite launches would be offset within weeks by the additional clean energy its system enables. For now, the project remains a distant concept. The journey from a single test launch to a fully operational constellation is long and uncertain. Yet, the proposal serves as a critical case study in the clash between technological solutions for climate change and their potential, irreversible consequences for the natural world. For astronomers and anyone who values a dark night sky, the success of such a project would be a dire outcome.