Inside the Danger Zone: Bay Area Experts Reveal the Looming Threat of ‘Kessler Syndrome’

Much of what we desire from our iPhones relies on satellites. This has made the sky above us busier than it has ever been.

Indeed, it’s concerningly congested. The recent surge of satellites for personal internet, Earth observation, and broad-scale communications is generating a newly packed aerial environment — SpaceX has deployed more operational satellites over the last five years than were in existence before. Astronomers in the Bay Area are divided on when this spatial congestion may pose a problem, but there is almost unanimous consensus that humanity has cause for concern regarding the so-called “Kessler Syndrome.” 

Named after astrophysicist Donald Kessler, stemming from a paper he authored on the proliferation of satellites, the “Kessler Syndrome” describes a situation where debris colliding with satellites above Earth initiates a chain reaction — fragmented components collide with other orbiting devices, forming a belt, or cloud, of space debris surrounding the planet. This cloud wouldn’t be visible from the ground, Paul Lynam, an astronomer with the University of California’s Lick Observatory, informed SFGATE, yet the debris could hinder or delay other launches, obstruct ground-based telescopes and disrupt the crucial modern systems that depend on satellite technology. Consider GPS, meteorological predictions, satellite television.

“It’s critical that individuals comprehend, it’s not going to be a distant, out-of-reach occurrence,” stated Lynam, who favors the term “cascade” over “syndrome” when describing the event. “It would influence everyone on the globe.”

Lynam indicated that in 2019 there were approximately 4,000 satellites orbiting. By the close of the decade, that number could exceed 60,000 — and their solar panels render them vulnerable targets for debris. Consequently, when operators such as SpaceX establish their satellites’ formations in orbit a few hundred miles above Earth, they strategically position them to avert collisions. However, near-collisions occur frequently, and Lynam mentioned that regulation is falling behind with regards to potential collision standoffs. In 2019, the European Space Agency reported having to alter a satellite’s trajectory after SpaceX declined to move its Starlink satellite off course.

The environment hasn’t always been so fortunate. In 2009, a commercial satellite from the United States collided with a decommissioned Russian satellite at over 15,000 mph, shattering it into thousands of debris bits and necessitating evasions by the International Space Station. The U.S., China, Russia, and India have each conducted anti-satellite missile tests at least once, destroying the units and generating orbital clouds of high-speed metal — the U.S. committed to ceasing such launches in 2022. A publicly available catalog backed by the U.S. currently monitors 19,100 debris pieces, plus an additional 17,400 so-called “analyst objects,” most of which are also debris.

All those fragments and those satellites pose a significant traffic management challenge, along with a regulatory quandary, Lynam explained. Governments, alongside, increasingly, private entities, would need to collaborate in developing a strategy.

“Historical precedent indicates that reaching any consensus or policy often takes several decades,” he remarked. “However, given the speed at which we are filling space with all these satellites, this matter needs to be resolved promptly.”

Nevertheless, space remains unfathomably vast, diminishing the likelihood that 4-inch debris pieces will collide with other objects out there. Many astronomers believe a resolution will be discovered before triggering a prolonged chain reaction of orbital collisions. (Two astronomers consulted by SFGATE, along with a CNN report released on December 27, referenced the 2013 film “Gravity” — it portrays the “Kessler Syndrome” scenario but is somewhat unrealistic regarding the cascade’s velocity.)

Abhishek Tripathi, from the UC Berkeley Space Sciences Lab, informed Aerospace America that “a multitude of issues must occur for us to find ourselves in a gradual Kessler Syndrome” and expressed concern that it could originate from a conflict where nations engage in satellite shoot-downs. Gerald McKeegan, an astronomer at Chabot Space & Science Center, pointed out the threat of meteoroids striking satellites in a message to SFGATE, but noted it would require “several years” of such impacts to induce serious alarm regarding a debris field.

SFGATE received a mix of concern and hope from UC Berkeley astronomer and educator Alex Filippenko. He indicated that the risk of a “Kessler Syndrome” is “certainly not existential in the forthcoming year or decade.” Atmospheric drag eventually decelerates and retrieves low-orbit satellites and debris back to Earth. At greater altitudes, there is a lower resistance, but fewer new satellites. Filippenko expressed optimism that industry coalitions will tackle the cleanup challenge and that creative solutions will attract venture funding to maintain the viability of space.

“If we don’t begin to take this issue seriously, it will escalate into a monumental problem in the coming decades, particularly within the next fifty to one hundred years,” Filippenko cautioned. “…If this syndrome were to materialize … launching further communications satellites or meteorological satellites would likely result in their destruction.”