Satellite swarms in low-Earth orbit are worsening. A prototype satellite, BlueWalker 3, launched in September 2022, is now among the top 10 brightest night sky objects. US-based AST SpaceMobile plans to deploy a full constellation of these super-bright satellites called BlueBird soon, intensifying the issue.
Satellite Constellations Obstructing View of Cosmic Objects
An international team of astronomers, led by Sangeetha Nandakumar from the University of Atacama, conducted meticulous observations of this satellite's luminosity, and their alarming findings were published in the prestigious journal Nature.
BlueWalker 3, a satellite from AST SpaceMobile, has highlighted the urgent need for regulatory measures. It boasts a large 64.3 square meter (693 square feet) antenna and was launched within a cylinder called the Launch Vehicle Adapter (LVA).
Observations of the satellite revealed significant fluctuations in brightness, starting brightly with a magnitude of 1, dimming to magnitude 6 by December 25, 2022, and then brightening to magnitude 0.4 by April 4, 2023.
Researchers found that its brightness correlated with its elevation and solar phase angle, impacting observations. The jettisoned LVA's magnitude exceeded recommended levels and was not promptly cataloged, posing risks to satellite path tracking.
AST SpaceMobile has unveiled an ambitious plan to launch the first five BlueBird satellites in early 2024, with an additional 20 slated for later in the same year. Should the satellite design remain unaltered, this could potentially introduce 25 objects into the night sky that outshine all but seven stars.
Currently, 8,693 artificial satellites orbiting Earth, primarily in low Earth orbit, and over 16,650 objects have been launched into space, with a significant increase in launches since 2019, including nearly 5,000 Starlink satellites.
It's estimated that by 2030, around 100,000 constellation satellites will be in Earth's orbit, substantially changing the appearance of the night sky. Some satellite operators, like Starlink, are attempting to mitigate their satellites' impact by applying paint to reduce brightness and addressing radio signal leaks.
The proliferation of such intensely bright satellites, exemplified by projects like Amazon's Project Kuiper and SpaceX's StarLink, poses a formidable challenge for astronomers, impeding their ability to conduct celestial observations across a range of electromagnetic spectra, including visible light, radio signals, and infrared emissions.
Addressing Satellite Swarms
Despite concerted efforts by the aerospace industry, policymakers, and astronomers to mitigate the disruptions caused by satellites to ground-based astronomy, the troubling trend of launching ever-larger and brighter satellites shows no signs of slowing down.
To address the growing issue of satellite luminosity, various mitigation strategies have been explored. One approach involves applying dark coatings to satellites, similar to StarLink's efforts, which can reduce their brightness by approximately half.
Nandakumar and her research team stress the importance of comprehensive assessments of potential sky impact before satellite launches, advocating for rigorous evaluations to be integrated into the approval process overseen by the Federal Aviation Administration.
Meanwhile, the problem of terrestrial light pollution continues to escalate, resulting in the night sky becoming approximately 10% brighter each year. A recent study has raised the unsettling prospect that within a generation or two, a significant portion of the global population may lose the opportunity to witness a starry night sky, with their view replaced by an uniformly glowing celestial expanse.
As we grapple with these challenges, the future of stargazing and celestial research hangs in the balance, prompting a crucial discussion on the need for balanced technological progress and the preservation of our view of the cosmos.
RELATED ARTICLE: SpaceX's Starlink Satellites Pose Radio Astronomy Concerns with 'Leaking' Low-Frequency Signals, Study Finds
Check out more news and information on Space in Science Times.
