The upper stage of a Chinese rocket launching a suite of internet satellites on Tuesday broke apart in space, leaving a debris field of at least 700 objects in one of the busiest zones in low Earth orbit.
The rocket debris was identified on Thursday by the U.S. Space Command, which tracks orbital objects with a network of radar and optical sensors. The command initially said the accident had produced more than 300 pieces of trackable debris. The service’s ground-based radar can track objects larger than 10 centimeters (4 inches).
Late Thursday, LeoLabs, a commercial space situational awareness company, He said the radar detected at least 700 objects. It is believed to have been hit by a Chinese rocket, and LeoLab said the number of pieces could be as high as 900.
The culprit was the second stage of China’s Long March 6A rocket, which was launched on Tuesday carrying the first of 18 satellites in China’s planned mega-satellite constellation that will eventually include several thousand spacecraft. The Long March 6A second stage appears to have disintegrated after placing the 18 satellites into a polar orbit.
“No imminent threats have been observed,” Space Command said in a statement, and “regular merger assessments are continuing in support of the safety and sustainability of the space domain.”LeoLab said radar data showed the rocket broke apart at an altitude of 503 miles (810 kilometers) at about 4:10 p.m. EDT (20:10 UTC) on Tuesday, about 13 and a half hours after lifting off from northern China.
At that altitude, it would take decades or centuries for the faint effects of air resistance to send the debris back into the atmosphere. If the object went any lower, its trajectory would intersect with SpaceX’s Starlink internet satellites, the International Space Station, other spacecraft, and thousands of other pieces of orbital debris, putting commercial and government satellites at risk of collision.
The new debris field of about 1,000 objects will be a significant addition to the roughly 46,000 objects Space Command tracks in Earth orbit. Statistics compiled by Jonathan McDowellAstrophysicists who monitor launches and spaceflight activity around the world say this would rank in the top five of all debris-creating events since the dawn of the space age.
This rocket has a proven track record.
The Long March 6A medium-sized rocket has been launched seven times since its debut in March 2022, and military and commercial satellite tracking organizations have reported that the rocket’s upper stage has disintegrated several times. In November 2022, the upper stage of a Long March 6A disintegrated in orbit, creating a debris field of more than 500 trackable objects. According to NASA’s Orbital Debris Program Office,.
Commercial satellite tracking companies have observed smaller distributions of debris after several Long March 6A flights this year.
The European Space Agency said in its Space Environment Statistics report that there have been more than 640 “unusual events leading to breakups, explosions, collisions or fragmentation” in orbit, meaning they happen often, but it’s not clear why the Long March 6A, which has a relatively short flight history, is particularly prone to generating debris.
Most rockets in operation today either reignite their engines and re-enter the atmosphere after deploying their payloads, or, if that’s not possible, “deactivate” themselves by emptying their propellant tanks and depleting their batteries to reduce the risk of explosion.
In a report last year, NASA’s Orbital Debris Program Office said the Long March 6A upper stage masses about 5,800 kilograms (12,800 pounds) without its kerosene and liquid oxygen propellants. The rocket is powered by a single YF-115 engine.
Tuesday’s launch marks the start of the rollout of China’s “Thousand Sails” internet network, which will initially consist of 1,296 satellites and could expand to more than 14,000 spacecraft, which will require numerous launches, some of which will likely use the Long March 6A.
“If even a fraction of the launches required to operate China’s massive constellation generate as much debris as this initial launch, it would result in a significant increase in the number of space debris in LEO,” said Audrey Shaffer, vice president of strategy and policy at Slingshot Aerospace, a commercial satellite tracking and analysis company.
China has had several space junk incidents beyond its recent problems with the Long March 6A rocket. In 2007, China destroyed its own spacecraft in an anti-satellite missile test, its worst ever incident of space junk generation, estimated at more than 3,000 trackable objects and more than 150,000 small pieces of debris.
The giant core stage of China’s Long March 5B rocket has re-entered the atmosphere uncontrollably four times between 2020 and 2022, raising concerns that falling debris could endanger people and property on Earth.
China plans further launches of its Long March 5B and Long March 6A rockets. China has continued to launch its Long March 5B rockets, despite the danger they pose to people on the ground. However, while chunks of orbital debris do not pose a direct threat to people on Earth, they do increase the risk to satellites of all nations, including China’s own spacecraft.
“Incidents such as this highlight the importance of adhering to existing space debris mitigation guidelines to reduce the generation of new space debris and underscore the need for strong space domain awareness capabilities to rapidly detect, track and classify newly launched space objects and screen them for potential collisions,” Schaffer said in a statement.
This story has been updated following the discovery of additional debris by LeoLabs.
