Another big Chinese rocket is due to go up on Sunday and once again no one knows where or when it will come down.
It will be a repeat of two previous launches of the same rocket, the Long March 5B, which is one of the largest currently in service and is designed to launch massive modules of China’s Tiangong Space Station into orbit. For about a week after launch, the world’s debris watchers will track the 10-story, 23-ton launch vehicle as air friction slowly pulls it back down.
The likelihood that it will hit anyone on Earth is slim, but significantly higher than what many space experts consider acceptable.
Here’s what you need to know about getting started.
When does it start and how can I see it?
The space station module, named Wentian, is scheduled to launch from Hainan Island in southern China around 2 p.m. Beijing time on Sunday. That’s about 2 a.m. Eastern time in the United States.
The state-sponsored Chinese TV will provide English language coverage of the launch, which you can watch in the video player embedded above.
What is China bringing to the market?
The powerful rocket was specially developed to launch parts of China’s Tiangong space station. The latest launch will carry Wentian, a laboratory module that will expand the station’s scientific research capabilities. Three more dormitories for astronauts and another airlock for spacewalking will also be added.
By April this year, China had completed a total of six missions to build the space station. Three crews of astronauts have lived aboard the station, including the trio who will receive the Wentian module this week.
The completion and operation of the space station are described in state media broadcasts as important to China’s national prestige.
“China is not and has not done anything that the US has not already done in space,” said Joan Johnson-Freese, a professor at the US Naval War College and former chair of the Department of National Security Affairs. “But it’s reaching technical parity, which is of great concern to the US”
She likened China’s space program to a tortoise versus the American rabbit, “although the tortoise has accelerated significantly in recent years.”
What is the risk of using the Long March 5B rocket?
The Long March 5B medium booster stage will propel the more than 50 foot long Wentian module all the way into orbit. This means that the booster will also reach orbit.
This differs from most rockets, where the lower stages usually fall back to earth immediately after launch. Upper stages that reach orbit typically re-ignite the engine after releasing their payloads, guiding them to re-entry over an unoccupied area, like the middle of an ocean.
If the rocket design has not changed, no thrusters will guide the descent, and booster thrusters cannot be restarted.
“It’s going to be the same story,” said Jonathan McDowell, an astrophysicist at the Center for Astrophysics in Cambridge, Mass., who tracks the comings and goings of objects in space. “It’s possible that the rocket designers made some minor changes to the rocket that would allow it to exit the stage with propulsion. But I don’t expect that.”
The final debris shower, with a few tons of metal expected to survive to the surface, could occur anywhere along the booster’s path, going north to 41.5 degrees north latitude and south to 41.5 degrees south latitude.
That means Chicago or Rome, both just north of the orbits, are not at risk, but Los Angeles, New York, Cairo and Sydney, Australia are among the cities the booster will fly over.
China’s space agencies did not respond to a request for an interview about the upcoming launch.
After the Long March 5B’s initial launch in 2020, the booster reentered over West Africa, with debris causing damage but no injuries in villages across the Ivory Coast nation.
The booster from the second launch in 2021 splashed harmlessly in the Indian Ocean near the Maldives. Still, Bill Nelson, the NASA administrator, issued a statement criticizing the Chinese. “It is clear that China is not meeting responsible standards regarding its space debris,” he said.
China dismissed these criticisms with great fanfare. Hua Chunying, a senior State Department spokeswoman, accused the United States of “hype.”
“The US and some other countries have been hyping the Chinese missile debris landing in recent days,” Ms. Hua said. “So far, no damage has been reported from the landing debris.”
Li You contributed to the research.