In 1978, NASA scientists Donald J. Kessler and Burton G. Cour-Palais proposed a scenario where the density of objects in Low Earth Orbit (LEO) would be high enough that collisions between objects would cause a cascade effect. In short, these collisions would create debris that would result in more collisions, more debris, and so on. This came to be known as the Kessler Syndrome, something astronomers, scientists, and space environmentalists have feared for many decades. In recent years, and with the deployment of more satellites than ever, the warning signs have become undeniable.
Currently, there is an estimated 13,000 metric tons (14,330 US tons) of “space junk” in LEO. With the breakup and another satellite in orbit – the Intelsat 33e satellite – the situation will only get worse. This broadband communications satellite was positioned about 35,000 km (21,750 mi) above the Indian Ocean in a geostationary orbit (GSO). According to initial reports issued on October 20th, the Intelsat 33e satellite experienced a sudden power loss. Hours later, the U.S. Space Forces (USSF) confirmed that the satellite appeared to have broken up into at least 20 pieces.
While there are no confirmed reports about what caused the breakup, this is hardly the first time a satellite broke up in orbit. In recent years, satellites have been lost through accidental collisions, increased solar activity, or deliberate destruction (during tests of anti-satellite technology). What is known is that the Intelsat 33e satellite, manufactured by Boeing and operated by the multinational satellite services provider Intelsat, has suffered several issues since it was launched in August 2016, especially where its propulsion is concerned.
An artist rendering of the Mission Extension Vehicle docked to an Intelsat satellite.
Credit: Northrop Grumman
The first occurred less than a year after the satellite was launched when it reached its desired orbit three months later than anticipated. This delay was reportedly due to an issue with its primary thruster, which is responsible for controlling the satellite’s altitude and acceleration. Another occurred when it performed a special maneuver that ensures satellites can maintain the right altitude (a “station-keeping activity”). During the maneuver, Intelsat 33e burned more fuel than expected, which reduced the time it would spend in orbit by three and a half years.
In addition, another Intelsat satellite of the same model (a Boeing-built EpicNG 702 MP) failed in 2019. However, they are hardly alone regarding satellites breaking up and producing debris. In July, the Russian commercial satellite RESURS-P1 fractured in LEO, creating over 100 pieces of debris that could be tracked (and likely many more that were too small to detect). That same month, the decommissioned Defense Meteorological Satellite Program (DMSP) 5D-2 F8 satellite broke up in orbit.
On August 9th, 2024, the upper stage of a Long March 6A (CZ-6A) rocket fragmented in orbit, creating a cloud of at least 283 pieces of trackable debris. The geomagnetic storm that took place on February 3rd, 2022, coincided with the launch of 49 Starlink satellites, most of which were lost as a result. It is unclear how this latest incident will affect objects in orbit. Still, astronomers are hopeful that studying the resulting debris will provide insight into the growing problem of space junk.
According to the ESA Space Debris Office, an estimated 40500 objects in LEO are larger than 10 cm (3.9 inches) in diameter. Moreover, there are an additional 1.1 million objects measuring 1 and 10 cm (0.39 to 3.9 inches) in diameter and 130 million objects 1 mm to 1 cm (0.039 to 0.39 inches). Based on the Space Debris Office’s estimates, this adds up to more than 13,000 metric tons, consisting of pieces of spent rocket stages, satellites, and other objects launched into orbit since 1957 – when Sputnik-1 became the first artificial satellite launched into orbit.
In a 2009 paper, Kessler declared that the orbital situation had already reached the point of instability. As he wrote:
“Modeling results supported by data from USAF tests, as well as by a number of independent scientists, have concluded that the current debris environment is “unstable”, or above a critical threshold, such that any attempt to achieve a growth-free small debris environment by eliminating sources of past debris will likely fail because fragments from future collisions will be generated faster than atmospheric drag will remove them.”
In accordance with the 1972 Convention of International Liability for Damage Caused by Space Objects, the country that launched a satellite into space is responsible for its breakup and debris. However, this is only in cases where fault can be proven, and it has been enforced only once in the more than 50 years since it was signed. It is unclear if Intelsat will be fined by the Federal Communications Commission (FCC) for this latest incident. Regardless, this latest breakup highlights the need for a more robust framework for mitigating future collisions and addressing space debris.
In particular, tracking technology will need to evolve so that more objects can be tracked. At present, about 36,860 space objects are regularly tracked by Space Surveillance Networks (SSNs) worldwide and maintained in their catalogs. In addition, active measures to safely track and remove debris from LEO are being researched and developed, some of which have already been deployed. Examples include the ADRAS-J satellite, which launched on February 18th, 2024.
Developed by the Tokyo-based company AstroScale, ADRAS-J is the first mission to approach and survey a piece of space debris. The Clearsat-1 satellite is also being developed by the ESA and Swiss startup ClearSpace Today. NASA is also developing the Active Debris Removal Vehicle (ADRV), a lightweight, single-use vehicle that will remove debris with a mass of 1,000–4,000 kg (1.1 to 4.4 U.S. tons) and at an altitude of 200–2,000 km (124 to 1240 mi).
In the meantime, Intelsat continues to investigate the loss of both of its satellites. According to the latest update issued by the company, which was posted on October 21st, 2024:
“We are coordinating with the satellite manufacturer, Boeing, and government agencies to analyze data and observations. A Failure Review Board has been convened to complete a comprehensive analysis of the cause of the anomaly. Since the anomaly, Intelsat has been in active dialogue with affected customers and partners. Migration and service restoration plans are well underway across the Intelsat fleet and third-party satellites.”