There is an estimated 10 percent risk of uncontrolled space rocket reentry casualties within the next decade, a guest speaker said in Philippine Space Agency (PhilSA)'s webinar entitled "Should We Worry About Orbital Debris?"
Ewan Wright, a Ph.D. student from the University of British Columbia, added that countries in the Global South will likely be the ones affected if ever one or more space rockets reenter the planet.
"Because of the latitudes of all of the rocket bodies currently in orbit, it’s more likely that they will reenter at or around the equator. This means that the populations there are more likely to have casualties.
"This is in some ways bad luck, but it represents an exportation of risk from space-faring states, such as the US and China, to the Global South," he explained.
Global South refers to regions in Latin America, Asia, Africa, and Oceania.
Wright noted that space rockets do not completely burn up upon reentry to Earth's surface and 20 to 40 percent of its mass survives and reaches the ground.
"When they do survive the reentry, there’s a small risk that it could hit a person, or a house, or a building, or maybe even something like a plane," he warned.
PhilSA said that this prediction will still change over time with "better use of controlled reentries" which, on the other hand, requires a bigger budget.
Meanwhile, Dr. Quentin Verspieren from the University of Tokyo’s Graduate School of Public Policy stated that "mitigation and remediation" are two of the approaches that can be done for better space debris management.
He is an assistant professor in the Science, Technology, and Innovation Governance program of the university.
Debris mitigation refers to the space actors generating less debris by "implementing better operational practices and satellite designs, post-mission disposal, and on-orbit repairs, among others" while debris remediation is the removal of existing and active debris.
There are technologies currently being developed to carry this out such as modification of debris orbits through shooting lasers and usage of net to "grab the satellites," Verspieren said.
"There are few countries investing on that," he added.
Aside from rockets, PhilSA said that satellites, non-functional spacecraft, satellite parts, and even fragments such as chipped-off paint are among the orbital debris that "could fall back to Earth or collide with other objects in orbit."