Half of all active satellites are now from SpaceX. Here’s why it can be a problem

SpaceX’s rapidly growing fleet of Starlink internet satellites now accounts for half of all active satellites in Earth orbit.

On February 27, the aerospace company launched 21 new satellites to join its Starlink broadband internet fleet. This brought the total number of active Starlink satellites to 3,660, or approximately 50% of the approximately 7,300 active satellites in orbitaccording to an analysis by astronomer Jonathan McDowell using data from SpaceX and the US Space Force.

“These large low-orbit internet constellations came out of nowhere in 2019, to dominate the space environment in 2023,” says McDowell, of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. “It’s really a massive change and a huge industrialization of low orbit.

SpaceX has been launching Starlink satellites since 2019 with the aim of bringing high-speed internet to remote areas of the globe. And for just as long, astronomers have been warning that the bright satellites could ruin their view of the cosmos leaving trails on the telescope images as they scroll (SN: 3/12/20).

Even the Hubble Space Telescope, which orbits more than 500 kilometers above the Earth’s surface, is vulnerable to these satellite trails, as well as those from other satellite constellations. From 2002 to 2021, the percentage of Hubble images affected by light from low-orbiting satellites increased by about 50%astronomer Sandor Kruk of the Max-Planck Institute for Extraterrestrial Physics in Garching, Germany, and his colleagues report on March 2 to natural astronomy.

The number of images partially blocked by satellites is still low, the team found, rising from almost 3% of images taken between 2002 and 2005 to just over 4% between 2018 and 2021 for one of the cameras. from Hubble. But there are already thousands more Starlink satellites than there were in 2021.

“The fraction of [Hubble] the images traversed by satellites are currently small with negligible impact on science,” Kruk and colleagues write. “However, the number of satellites and space debris will only increase in the future.” The team predicts that by the 2030s, the probability of a satellite crossing Hubble’s field of view every time it takes an image will be between 20 and 50 percent.

The sudden jump of Starlink satellites also poses a problem for space traffic, says astronomer Samantha Lawler of the University of Regina in Canada. Starlink satellites all orbit at a similar distance from Earth, just over 500 kilometers.

“Starlink is the densest parcel of space that has ever existed,” Lawler says. The satellites are constantly moving apart from each other to avoid collision (SN: 02/12/09). And it’s a popular orbital altitude – Hubble is there, as is the International Space Station and the Chinese Space Station.

“If there is some kind of collision [between Starlinks]some sort of accident, it could immediately affect human lives,” Lawler says.

SpaceX launches Starlink satellites about once a week — it launched 51 more on March 3. And it’s not the only company launching constellations of internet satellites. By the 2030s, there could be 100,000 satellites in low Earth orbit.

So far, there are no international regulations to limit the number of satellites a private company can launch or to limit the orbits they can occupy.

“The speed of business development is much faster than the speed of regulatory change,” McDowell says. “There needs to be an overhaul of space traffic management and space regulation in general to deal with these massive commercial projects.”