SpaceX has asked the FAA to correct a report that says there is a growing danger of falling debris from satellites being launched. The FAA acknowledged that the risk from Starlink satellites is minimal if the company guarantees their destruction upon re-entry
SpaceX has asked the Federal Aviation Administration (FAA) to correct a report to Congress that states that by 2035, falling debris from low Earth orbit (LEO) satellite constellations could injure or kill someone every two years if the pace of launches remains.
In an Oct. 9 letter to the FAA and Congress, SpaceX chief engineer David Goldstein said the report relied entirely on “fundamentally flawed analysis” based on assumptions, speculation, and outdated research. In the report, the regulator said that by 2035, up to 28,000 potentially dangerous pieces of debris from satellites and the rockets that launch them could remain in Earth’s orbit each year, especially if the pace of expansion of SpaceX’s Starlink satellites continues.
SpaceX has launched 5,000 Starlink satellites since 2019, has permission from the FCC to expand the constellation to 12,000 units, and is seeking international approvals to further expand to 40,000 units in orbit. According to the FAA report, Starlink satellites account for more than 85% of the expected risk of danger to people and aviation from falling space debris.
In 2020, Congress directed the FAA to submit a report on the risks associated with the controlled and uncontrolled return of satellites from “mega-constellations” from orbit to Earth. In 2021, the FAA commissioned Aerospace Corp., a federally funded nonprofit organization focused on space, to conduct a technical assessment of the growth of satellite constellations and the risks resulting from the return of such satellites and the rocket stages that launch them.
The FAA has directed Aerospace Corp to focus on satellites launched by the US under FAA license. Aerospace Corp has concluded that the probability of a “downed aircraft accident” resulting from falling space debris in 2035 would be 0.0007 events per year, which would likely result in the death of the entire crew of the aircraft.
Dispute between SpaceX and FAA over the risk of falling satellite debris
By 2035, if the expected growth in the number of satellites in orbit materializes and Starlink satellite debris persists as it passes through the atmosphere, the number of dangerous pieces of debris each year will be 28,000, and the number of casualties will be 0.6 per year – we can expect that every two years one person will be injured or killed. Some debris also poses a risk to people on board aircraft. A fragment that could harm or kill a person on Earth could fatally damage an aircraft. The probability of a collision with an airplane in 2035 will be 0.0007 per year.
However, the FAA acknowledged that if SpaceX reports valid information that there is zero debris from the Starlink satellites to date and that their components are fragile enough to burn up completely in the atmosphere, then “the increase in risk on return is minimal compared to the current risk.”
According to satellite tracking data and observations by astrophysicist Jonathan McDowell, 358 Starlink satellites have already left orbit. However, there were no reports that fragments reached the Earth’s surface.
Determining the exact risk associated with the return of satellite debris is difficult due to errors in calculations of their persistence. Marlon Sorge, executive director of the Center for the Study of Orbital and Re-entry Debris, said: “The phenomenon is quite complex, and the actual data available is limited.” He also noted that their analysis sought to provide insight into what actions lead to consequences from debris returning to Earth so that steps can be taken to reduce potential risks: “Such information will help develop possible future changes in regulations due to possible increased flows orbital traffic.”
According to Goldstein, Aerospace Corp. did not attempt to review the actual data on the Starlink debris, and errors in the analysis “could have been avoided if Aerospace had simply asked basic questions to SpaceX, but it chose not to do so.”
Goldstein also criticized Aerospace Corp and the FAA for outdated data in a 2021 analysis of the size of satellite constellations. The report suggests there are 54,902 FCC-licensed satellites in space, according to 12 applications from nine operators, but updated data reduced that number by 7,518. Constellations licensed by China and other foreign countries were included in the report, while Amazon plans to launch its own The satellite “constellation” of more than 3,200 satellites was not taken into account next year.
“The fact that the FAA accepted Aerospace’s report without question or review raises concerns about the FAA’s competence,” Goldstein wrote.
