Falling space junk has up to 10% chance of killing someone in next 10 years: B.C. study

Space junk re-entering Earth's atmosphere could have as much as a one-in-10 chance of killing a person in the next decade, a recent B.C. study suggests.

A team of researchers from the University of British Columbia said there's a six- to 10-per-cent chance someone could be severely injured or killed by falling abandoned rocket pieces. Results of the research were published in Nature Astronomy this week. 

The team explained that rockets are used to launch satellites into space and that parts of those rockets are often left in orbit. But if they're low enough, they can re-enter the atmosphere "in an uncontrolled way."

The researchers are calling for governments to require that rocket stages be guided back to Earth, even though it'll likely increase costs.

"Is it permissible to regard the loss of human life as just a cost of doing business, or is it something that we should seek to protect when we can? And that's the crucial point here: we can protect against this risk," said lead author Michael Byers, professor in UBC's department of political science, in a news release about the team's findings.

The research looked at more than 30 years' worth of data and calculated possible risk to human life over the next 10 years. Byers explained the calculations consider possible casualties for people on the ground, but don't look at the likelihood of a worst-case scenario like a piece of debris hitting an airplane.

The team also determined that rocket debris is three times more likely to land in the global south, along latitudes of Jakarta, Dhaka and Lagos, than those of New York, Beijing or Moscow, because of the orbits used when launching satellites.

Byers explained some measures to mitigate the risk could include having engines that reignite and safely guide rocket bodies to remote areas.

"Risks have been evaluated on a per-launch basis so far, giving people the sense that the risk is so small that it can safely be ignored. But the cumulative risk is not that small," Aaron Boley, associate professor in the department of physics and astronomy, said in the news release.

"There have been no reported casualties yet, and no mass casualty event, but do we wait for that moment and then react, particularly when it involves human life, or do we try and get in front of it?"