BEIJING (AP) — The largest section of the rocket that launched the main module of China's first permanent space station into orbit is expected to plunge back to Earth as early as Saturday at an unknown location.
Usually, discarded core, or first-stage, rockets reenter soon after liftoff, generally over water, and don't go into orbit as this one did.
China's space agency has yet to say whether the "core stage" of the vast Long March 5B rocket is being controlled or will make an out-of-control descent.
Defense Department spokesperson Mike Howard said to CNN that the "exact entry point into the Earth's atmosphere" can't be pinpointed until within hours of reentry.
According to CNN, the 18th Space Control Squadron will post updates about the rocket's location on the Space Track website.
Jonathan McDowell, an astrophysicist at the Astrophysics Center at Harvard University, said in an interview with CNN that there is no need for people to take precautions, adding that the "risk that it will hit you is incredibly tiny."
This isn't the first time such an event has occurred.
Last May, another Chinese rocket fell uncontrolled into the Atlantic Ocean off West Africa.
The U.S. Defense Department expects the rocket stage to fall to Earth on Saturday.