A portion of a massive Chinese rocket is expected to fall back to Earth as early as Saturday, but neither its Chinese handlers — nor anyone else — can say for certain exactly where.
The Pentagon and White House both acknowledged this week they are tracking the uncontrolled Chinese rocket that is anticipated to reenter Earth’s atmosphere shortly, amid speculation that the flight path as it falls could take it over a string of U.S. cities.
“Its exact entry point into the Earth’s atmosphere cannot be pinpointed until within hours of its reentry, which is expected around May 8,” Pentagon spokesman Mike Howard told reporters. “All debris can be potential threats to spaceflight safety and the space domain.”
European space officials, also keeping an eye on the rocket, say its orbital path is believed to take it on a trajectory just north of such major cities as New York and Madrid and as far south as southern Chile and New Zealand.
The Long March 5B rocket had launched a section of China’s first permanent space station last week, but the discarded rocket section was not guided into a controlled demolition as is usually the case. Critics say China has not given out key details about the rocket’s stage and trajectory, or whether its core stage will make an uncontrolled landing or not, according to the Associated Press. “An exact prediction is not yet possible as there is still a considerable level of uncertainty,” said Heather Golden, spokeswoman for the Aerospace Corporation. She said the nonprofit’s predicted re-entry time for the rocket as of Wednesday afternoon is May 9 at 02:29 UTC, with a 22-hour window on either side of the estimate.
While the Earth’s atmosphere burns up most smaller space debris, there are concerns that pieces of this 21-ton rocket could survive the fiery re-entry phase and potentially land in an inhabited area.
Beijing has stepped up its rivalry to the U.S. in space, landing a mission last year for the first time on the dark side of the Moon, and has expressed irritation with the international focus on its wayward craft. The state-controlled Global Times, which has close ties to the ruling Chinese Communist Party, reported that debris from the carrier rocket is very likely to land in international waters and cited Chinese space analysts who assured people there was no cause for concern.
The newspaper, published by the Chinese Communist Party, said wreckage from rocket launches falling back to Earth is a common incident, “nothing but Western hype” of the China threat in space technology advancement.
Jonathan McDowell, an astrophysicist at the Astrophysics Center at Harvard University, tweeted that people shouldn’t lose sleep over the possibility that the rocket might hit them.
He said the risk of the rocket causing damage is “pretty small,” but “not negligible,” CNN reported. The astrophysicist noted that pinpointing where the debris will land is almost impossible at this point due to the rocket’s speed, which can circle the world 30 times in a two-day period.
The European Union’s Space Surveillance and Tracking agency on Wednesday tweeted that its radars can confirm the rocket is tumbling and that the narrowed window for re-entering Earth’s atmosphere is May 8 to 9.
About 50 or 60 incidents where objects weighing an average of 100 tons re-enter the Earth’s atmosphere in a similar uncontrolled way, Holger Krag of the European Space Agency, told SpaceNews. But since 1990, no object weighing more than 10 tons has deliberately been left in orbit and allowed to re-enter Earth’s atmosphere with no clear landing plan, Snopes.com reported.
The Long March 5B rocket carried its core capsule of its space station on April 29, launching the biggest and heaviest spacecraft China has ever constructed to a low-Earth orbit, the China National Space Administration said. The country is planning 10 more launches to bring more parts of the space station into orbit.
Mike Glenn contributed to this article, which is based in part on wire service reports.