SpaceX Says 4,400 “Star Chain” Satellites Will Drop to Orbit This Year, Provoking Discontent among Astronomers from All Countries
By the end of 2025, the number of “Star Chain” Internet satellites in orbit by the U.S. space exploration technology company (SpaceX) had approached 10,000, causing growing controversy. The U.S. “Space” website said on January 2 that the company announced that for “safety reasons,” it would reduce the current 4,400 “Star Chain” satellites operating at a distance of 550 kilometers from the ground to about 480 kilometers in 2026. This move also caused dissatisfaction among astronomers from various countries.
“Star Chain is undergoing a major restructuring of its satellite constellations, with a focus on improving space safety,” the report said on January 1 on social media platform X. According to Nichols, this move will reduce the time it takes for a defective satellite to burn out in the Earth‘s atmosphere and reduce the “probability” of collisions with other satellites and space debris.
According to SpaceX‘s plan, if the “Star Chain” satellite fails or is retired, it will gradually lower its altitude due to the thin air resistance in its operating orbit, eventually returning to the atmosphere within a few months and burning itself out. However, as solar activity shifts from its current peak of activity to a very low minimum period (around 2030), the air resistance in near-Earth orbit decreases, which also means that the “Star Chain” satellite will take longer to return to the atmosphere. Nichols said that, due to the minimum period, the satellite may take more than four years to return to the atmosphere from an orbital altitude of 550 kilometers. If it chooses lower orbits, the process takes only a few months.
Nichols also said, “These measures will further improve the safety of the constellation, especially in dealing with uncontrollable risks, such as uncoordinated maneuvers and launches by other satellite operators.” The U.S. “business insider” website noted that last December, SpaceX reported that a “Star Chain” satellite brushed past nine Chinese satellites and nearly collided. The company also reported that another “Star Chain” satellite was suspected to have exploded late last year and released a small amount of “traceable low-relative velocity objects” in orbit. Hong Kong‘s South China Morning Post reported on January 2 that the Chinese representative spoke at a meeting of the UN Security Council last December, saying that the unbridled expansion of the commercial satellite constellations of individual countries, lacking effective regulation, poses obvious security challenges. “Take ‘Star Chain’ as an example. Its orbiting satellites severely overcrowd orbital resources, increasing the risk of spacecraft collisions and creating space debris.”
According to the European Space Agency‘s monitoring data, by the end of 2025, more than 14,000 satellites from around the world were operating in different altitude orbits around the Earth. In particular, near-Earth orbits are becoming increasingly crowded, with “Star Chains” being the main reason: about two-thirds of the orbiting satellites belong to “Star Chains” Internet satellites. Related statistics show that SpaceX has about 9,400 orbiting satellites, including more than 8,000 already operational “Star Chains” satellites, as well as hundreds of satellites being tested and waiting to be activated. This situation has raised concerns about the risk of satellite collisions and could increase the number of massive debris in orbit. The European Space Agency estimates that there are approximately 1.2 million pieces of space between 0.4 inches (1 inch is about 2.54 centimeters) and 4 inches in orbit, all of which are orbiting the Earth at speeds of 17,000 miles per hour (1 mile is about 1.6 kilometers), potentially causing damage to satellites and manned space launches.
Nichols said that although lowering the operational altitude of the 4,400 “Star Chain” satellites to lower orbits would cause their distances to get closer to each other, the effect “contrary to people‘s intuition, would reduce the risk of collisions”. He explained that because there are fewer satellites and space fragments in lower orbits, although the “Star Chain” satellites are arranged more densely, they follow pre-arranged operational paths distributed across dozens of orbits, which can reduce the probability of safety accidents.
In addition to this, SpaceX has other plans — making the satellites operate at higher altitudes closer to the ground will slightly improve latency, that is, reduce the time required for internet signals to travel between the transmitter and receiver, thereby improving the online experience for Star Chain users. SpaceX founder and CEO Elon Musk says this is actually the “greatest advantage” of reducing the operational altitude of Star Chain satellites. He writes on social media platform X: “With the same antenna size, the beam diameter is smaller, which allows Star Chain to serve higher density users.”
However, this move was also opposed by astronomers from various countries. This was because dense “Star Chain” satellites would form bright light streaks when moving through the night sky, directly destroying long-exposed deep-space images, thereby affecting astronomers‘ observations of the starry sky. And lower orbital altitudes would make the “Star Chain” satellites appear brighter in the sky.