Elon Musk’s SpaceX has renewed its push for approval to significantly expand the Starlink satellite constellation, seeking permission from the Federal Communications Commission (FCC) to launch nearly 30,000 more satellites into low-Earth orbit.
This latest request, which seeks to deploy up to 29,988 satellites, aims to improve global internet connectivity by bringing gigabit speeds and “ubiquitous mobile connectivity to all Americans” and billions of other users worldwide. However, astronomers are raising the alarm over the potential risks such a massive deployment poses to scientific research and the pristine night sky, according to The Independent.
The application, filed on October 11, seeks permission not only for a larger satellite constellation but also to operate at lower orbits for the second-generation system and to utilize more radio frequencies. SpaceX argues that the additional frequencies will not significantly interfere with other spectrum users. If approved, the company plans to launch the satellites using its powerful Starship mega-rocket.
SpaceX’s current request mirrors a similar one made over two years ago when the company also sought permission to deploy up to 30,000 satellites. At that time, the FCC granted approval for the deployment of only 7,500 satellites, citing the need to protect other satellite operators from harmful interference and to maintain a “safe space environment.” The latest 20-page filing, however, does not address how the new proposal would mitigate potential impacts, which is fueling concerns among scientists.
Astronomers Sound the Alarm
The rapidly increasing number of satellites orbiting Earth has raised serious concerns among astronomers, who argue that large satellite constellations threaten both optical and radio astronomy. Piero Benvenuti, director of the International Astronomical Union’s (IAU) Centre for the Protection of the Dark and Quiet Sky from Satellite Constellation Interference, pointed out that the potential impact has been recognized for years.
“Obviously, the impact is what we have already known for several years,” Benvenuti told The Independent on Monday, adding that there is a “severe impact on astronomy, both optical and radio astronomy, and also the visibility of the pristine sky.”
One of the main issues is the satellites’ brightness. The reflected sunlight from these objects can create bright streaks in the sky, disrupting telescopes’ ability to capture clear images of stars, planets, and other celestial objects. The light pollution caused by satellite reflections can compromise long-exposure observations, which are critical for studying faint objects in the cosmos.
Radio Astronomy Under Threat
Concerns extend beyond visual observations to radio astronomy, where the impact could be even more severe. The radio frequencies used by the Starlink satellites for communication can generate electromagnetic interference that affects the ability of radio telescopes to detect faint signals from space.
Last month, astronomers highlighted that radio emissions from Starlink satellites had complicated efforts to observe exoplanets and black holes using the European Low-Frequency Array (LOFAR) network.
“Although the bandwidth they are using is not among the so-called ‘protected’ radio bands for radio astronomy, they are very close to them,” Benvenuti explained. “And so, there is always spillover of noise, and it’s very difficult, in that case, to avoid interference.”
International Efforts to Mitigate Impacts
In response to growing concerns, the IAU has been collaborating with SpaceX to develop mitigation strategies aimed at protecting astronomy. One approach under consideration is to reduce the satellites’ reflectivity to make them “essentially invisible to the naked eye.”
This could involve using advanced materials and coatings that absorb sunlight rather than reflecting it, which would help minimize the light pollution caused by satellite reflections. However, Benvenuti noted that achieving such invisibility for thousands of satellites is a challenging technical hurdle.
“That is very hard to obtain, but at least they try to work on the material science to find the coating of the satellite that would not reflect, like a mirror, the light of the sun,” he explained.
Another strategy being discussed involves improving satellite tracking accuracy. Knowing the exact positions of satellites could allow astronomers to adjust their observations and avoid satellite trails. However, implementing this solution is complex, as satellites are constantly maneuvering to avoid collisions with other objects in space, such as the International Space Station and other debris.
To address radio frequency interference, one suggestion is for satellite operators to adjust the transmission beams away from major radio astronomy facilities when passing overhead. Yet, as the number of satellites in orbit continues to grow, managing such coordination becomes increasingly difficult.
An Exponentially Crowded Sky
The surge in satellite numbers is happening at a staggering pace. Just four years ago, there were approximately 2,200 satellites orbiting the Earth in low-Earth orbit. Today, the figure has ballooned to around 14,000, driven in large part by Starlink’s rapid expansion. With SpaceX’s latest proposal, the trend shows no signs of slowing down.
Moreover, the International Telecommunications Union has received requests to launch an astonishing 1.7 million satellites in total, although only a small fraction of this number is expected to be realized. Even so, launching just a few percent could increase the total number of satellites in orbit to over 150,000.
“The scary news is that the International Telecommunications Union currently has received requests for launching 1.7 million satellites,” Benvenuti remarked. “That will become … quite challenging.” The increased congestion in low-Earth orbit not only heightens the risk of collisions and the creation of space debris but also complicates efforts to maintain the safety of orbital operations.
Starlink’s Expansion Plans
Despite the concerns, Starlink continues to expand its reach. In September, the satellite internet service reached four million subscribers, underscoring the high demand for reliable global internet access. To accommodate this growing user base and meet future connectivity needs, Musk recently outlined plans for deploying third-generation Starlink satellites at an altitude of 350 kilometers.
These new satellites will feature larger antennas capable of multi-gigabit bandwidth, reducing latency to an estimated 5 milliseconds for round-trip communications. This lower orbit placement is designed to improve the network’s speed and responsiveness, making it even more appealing for high-performance applications.
SpaceX intends to deploy the third-generation satellites using its Starship mega-rocket, a next-generation launch vehicle capable of carrying large payloads into orbit. The success of Starship is central to Musk’s vision of creating a vast satellite constellation that not only powers global connectivity but also supports human space exploration and other ambitious space endeavors.
While Starlink-powered internet access can drive economic growth and improve quality of life, particularly in underserved regions, the impact on scientific research and the night sky has become a big issue.
