Experts warn that falling rockets and satellites might endanger airplanes as Earth’s orbit fills.
“There is a real risk,” University of British Columbia associate professor Aaron Boley told CTVNews.ca. “The uses of space are simply expanding, and as we put large objects in orbit, they come down eventually, and if they’re uncontrolled, that’s a hazard to people on the ground, at sea, and in airplanes.”
Boley and a colleague said that recent increases in flights and satellite launches might lead to an aviation disaster unless rocket re-entries are effectively tracked, regulated, and responded to. UBC political scientist Michael Byers, Boley’s co-author, estimates a 10% probability space debris may kill someone in the next decade.
Boley said it should have a controlled re-entry if it can. “And if it absolutely cannot have a controlled re-entry then there are other things that need to be done so that we have as much knowledge as we can moving ahead to make educated judgments and we’re not just suddenly responding to every new large object that’s coming down. Right now.”
Rockets launch satellites into orbit and then leave them for uncontrolled re-entries.
“The atmosphere is slowly causing that orbit to decay and at some point it re-enters and you don’t know where along its trajectory it’s ultimately going to re-enter,” Boley said.
Controlled re-entries, like astronauts returning from the International Space Station, are planned.
“You have things like re-ignitable engines, which many rockets have, and they can direct the trajectory then so it goes into a place, say, in the ocean that is out of way,” Boley added. “That extra fuel weighs down payload delivery.” It costs.”
Several incidences have generated worries, but no rocket or satellite debris has damaged an airliner. A Chinese rocket crashed in May 2020, scattering debris across the Ivory Coast. France and Spain barred airspace for another Chinese rocket that crashed into the Pacific Ocean in November 2022.
“So they had this sudden rerouting of aircraft and it caused large delays, there was a large economic hit associated with it,” Boley added.
The Canadian government’s aviation incident database indicates suspected space debris falling over or near the nation, including on Jan. 18, 2007, when a United Airlines aircraft “reported a large flaming ball with… debris or wreckage emanating from it” over the arctic.
“It’s largely a Wild West,” Boley remarked of rocket launch laws. When a state launches a satellite and lets it fall uncontrolled, it exports risk. So, the rest of the globe takes on a lot of that launch’s risk.”
The International Civil Aviation Organization and the Air Line Pilots Association have taken note.
UBC’s Outer Space Institute’s “Montreal Recommendations” called for “global standards” on uncontrolled re-entries in March 2023, when over 7,000 objects were in low earth orbit.
“Tens of thousands more satellites are licensed, while hundreds of thousands more are proposed…” “Many will reenter Earth’s atmosphere in years and decades,” it said. “Due to their relative speed of impact, even small or light pieces of debris that may be harmless for people on the ground could fatally damage an aircraft in flight or otherwise necessitate emergency action by its crew.”
UBC’s Boley and Byers, retired astronaut and former Canadian cabinet minister Marc Garneau, the French Space Agency’s inspector general, and the U.S. Air Force’s space safety officer signed the letter.
Boley thinks international regulations will be established before an uncontrolled rocket re-entry causes an aviation tragedy.
“Ultimately, [we’re] throwing stuff up and letting things just crash down under the paradigm that the earth is so large, we don’t need to worry about it,” Boley added. But, you know, that’s something we’ve done several times: the seas are so huge, we don’t need to care about this plastic we’re throwing in; the atmosphere contains so much stuff, we don’t need to worry about all the carbon we’re putting in it. We repeat.”