A Long March 6A rocket carrying 18 satellites lifts off Tuesday from China's Taiyuan Satellite Launch Center.

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One of China’s Long March 6A rockets has broken apart in low-Earth orbit and created a debris cloud consisting of hundreds of pieces, according to multiple space debris-tracking entities.

The rocket launched from the Taiyuan Satellite Launch Center on Tuesday to deliver 18 G60 satellites into orbit, which marks just the first deployment for the Shanghai Spacecom Satellite Technology group’s Thousand Sails constellation.

The megaconstellation of satellites will eventually include 1,296 satellites, and there are plans to expand the capacity to around 14,000 to rival SpaceX’s Starlink satellites.

Shanghai Spacecom Satellite Technology did not respond to CNN’s request for comment. US Space Command, a branch of the US Department of Defense, confirmed the breakup of the rocket on Thursday.

“USSPACECOM has observed no immediate threats and continues to conduct routine conjunction assessments to support the safety and sustainability of the space domain,” according to a US Space Command spokesperson.

US Space Command is continuing to track the debris and provide information to NASA.

“There has been no immediate threat to the International Space Station observed as a result of this breakup,” said Rob Margetta, public affairs officer at NASA headquarters.

The amount of tracked debris changed by the hour Thursday, beginning with more than 50 tracked by Slingshot Aerospace’s Global Sensor Network. Then, US Space Command said it was tracking more than 300 pieces.

Now, radar data from tracking organization LeoLabs has confirmed that the event resulted in at least 700 debris fragments and potentially more than 900.

‘A significant hazard’

It is believed that the rocket broke apart at 503 miles (810 kilometers) above Earth’s surface, and the debris poses “a significant hazard to (low-Earth orbit) constellations” below 497 miles (800 kilometers) altitude, according to Slingshot.

For reference, the International Space Station orbits about 254 miles (408 kilometers) above the Earth.

Slingshot’s Horus sensor systems, which provide satellite tracking in low-Earth orbit, “detected a series of bright, unexpected objects moving along the same orbital path as the rocket body and the G60 satellites it deployed.”

The true risks of the debris cloud won’t be known until experts have a chance to analyze it fully, which could take another day or so. And the reason for the rocket breakup remains unknown.

Because the Chinese satellites were delivered into orbit around Earth’s poles, rather than an equatorial orbit, they will “pack a real punch with other objects not in polar orbit” like two cars colliding in an intersection, said John L. Crassidis, Moog Professor of Innovation within the University at Buffalo’s School of Engineering and Applied Sciences.

Everything in low-Earth orbit travels at 17,500 miles per hour, Crassidis said.

“The worst-case scenario is when any part of the debris field collides with something that is moving around the equator,” he said. “That’s a T-bone intersection case. Imagine two cars going at 17,000 MPH and crashing at a T-bone intersection. Obviously, that’s bad. Overall any object in its path will still be a bad situation.”

Future space debris risks

Given the altitude where the breakup occurred, the debris will likely remain in place for several years, and some could remain for decades, but it’s hard to predict how long without knowing the shapes of the debris, Crassidis said.

It’s the second time one of these rocket bodies has experienced a significant breakup event in low-Earth orbit, according to Victoria Heath, associate director of marketing and communications for LeoLabs.

Another Long March 6A rocket body exploded in a region of low-Earth orbit densely populated by satellites on November 12, 2022, and the resulting 500-plus debris fragments were distributed between 198 miles and 932 miles (320 and 1,500 kilometers) and increased the collision risk with satellites, especially at the center of the debris cloud, according to LeoLabs.

The company conducted an analysis and concluded that the November 2022 event was triggered by an issue related to the spacecraft’s propulsion system, rather than fragmenting due to the rocket colliding with another object.

There are nearly 1,000 abandoned rocket bodies in low-Earth orbit today, according to LeoLabs, and that number only continues to increase due to an uptick in launches as more countries focus on their space ambitions.

“If even a fraction of the launches needed to field this Chinese mega-constellation generate as much debris as this first launch, the result would be a notable addition to the space debris population in (low-Earth orbit),” said Audrey Schaffer, vice president of strategy and policy for Slingshot Aerospace, in a statement.

“Events like this highlight the importance of adherence to existing space debris mitigation guidelines to reduce the creation of new space debris and underscore the need for robust space domain awareness capabilities to rapidly detect, track, and catalog newly-launched space objects so they can be screened for potential conjunctions.”