Canada and spacefaring countries, including the United States and China, are being asked to take action to reduce the risks posed by rocket debris falling back to Earth.
A letter to space agencies around the world, organized by the Vancouver-based Outer Space Institute, a global network of experts, is warning of the “fast-growing risk” to humanity as rocket launches keep rising to put increasing numbers of satellites into orbit.
This is leading to an ever-rising number of rocket bodies being abandoned in orbit.
They warn that countries in the “Global South” – South America, Africa, Oceania and Asia – will face disproportionately high risks of deaths from space junk because of where discarded rocket bodies tend to orbit, and fall to Earth.
The institute, whose co-directors include Michael Byers, the Canada Research Chair in Global Politics and International Law at the University of British Columbia, has gathered about 200 signatures from academics, astronauts, former politicians and former space agency leaders asking countries to beef up rocket launch rules to require the “controlled re-entry” of space debris, starting with rocket bodies. This would mean guiding these objects back to Earth so they don’t risk killing people.
Signatories include retired Canadian astronaut Chris Hadfield, Brian J. Egan, a former chief legal adviser to the U.S. Department of State during the Obama administration, and three former directors of space agencies, including France’s Gérard Brachet.
They urge countries to act before a disaster hits. In the letter, the signatories note how the global shipping industry resisted calls to require double-hulls for oil tankers, and it was only after the 1989 Exxon Valdez oil spill off Alaska that the world acted.
“With rocket body re-entries, the only unclear thing is whether the major spacefaring states will require a safer approach before an accident occurs,” the letter warns.
It is addressed to the leaders of space agencies around the world, including Lisa Campbell, president of the Canadian Space Agency, and her counterparts in the U.S. (the National Aeronautic and Space Administration), China, Russia, the European Union, Japan and India.
In 2021, the number of rockets making it into orbit hit 135, the largest number in one year, according to Spaceflightnow.com. And about 65 per cent of the rocket launches into low-Earth orbit – 100 kilometres to 2,000 kilometres above the surface – led to the uncontrolled re-entry of rocket bodies.
“Although most of the debris pieces are small, even a small piece could be enough to kill a person or critically damage an aircraft,” the letter warns.
In 2020, pieces of China’s Long March 5B rocket falling back to Earth damaged buildings in the Ivory Coast. In 2018, titanium pressure vessels from the upper stage of a Russian Zenit rocket crashed in Peru.
As countries and corporations strive to put a growing number of satellites in orbit, the number of rockets required is going to rise steeply. An estimated 18,500 satellites are predicted to enter orbit between 2022 and 2031, according to a recent estimate by Euroconsult, a consultancy specializing in the space market. That would be a big increase from the approximately 5,500 active satellites in orbit today.
But another, widely repeated estimate, from a 2021 research paper prepared for the National Science Foundation in the United States, predicts 100,000 satellites could be in orbit by 2030.
The letter writers note that some countries have set a safety threshold below which they do not require controlled re-entry of rocket bodies, based on the probability of casualties that would result. Even then, countries such as the United States frequently grant exemptions from their own rules, allowing higher-risk launches. Between 2011 and 2018, they said, the U.S. waived what are called “orbital debris mitigation” practices in more than half of the launches conducted on its behalf.