China is set to launch the next piece of its space station on Sunday — in a rocket that previously rained parts back onto Earth

The second module of China's new space station is expected to be launched on Sunday, but it's not yet known if the rocket that will bring it down will work again.

There are three different crews that have visited the live-in laboratory. The astronauts are waiting for the Wentian module, which is intended for science and biology experiments, to arrive and be attached.

China Manned Space Engineering Office/cnsphoto/Reuters

Brian Harvey, author of "China in Space: The Great Leap forward", said thatWentian is a critical stage in the building of China's space station. Nothing can be taken for granted, even for the first time, because the crew has overseen numerous undockings and redockings.

When there are airspace-clearance notices over China's facilities on Hainan Island, it's likely that Wentian will be launched on Sunday. On Monday, the Long March 5B rocket rolled out from its assembly building and onto the launch pad, with the Wentian module inside its fairing.

China might let the rocket's body fall back to Earth uncontrolled — for the third time

When China launched a Long March 5B rocket in April 2021, it drew international outrage as the rocket's body slowly lost altitude until it fell into the ocean.

It traveled from Los Angeles to New York to Beijing, as well as down through most of Australia, Africa, and South America.

The rocket body fell into the Indian Ocean more than a week after it was launched. The chances that it would hit humans or property were low, but space- industry experts called for China to redesign the rocket or its launch plans so that it wouldn't happen again.

It is not clear if the space agency did that for Wentian.

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Normally, rockets are programmed to push themselves into the atmosphere after launch, controlling their fall back to Earth so that they land in remote ocean areas.

John Logsdon, the founder of George Washington University's Space Policy Institute, told Insider as the world waited for the rocket body to fall that there was rarely concern about reentering.

Is it just carelessness with the guidelines? It wasn't designed so it could do a controlled reentry. Logsdon said whatever. A lot of people are at risk.

The Long March 5B was launched in May 2020 in a test. The rocket's core stage fell without warning. The US Space Force's 18th Space Control squadron said it reentered Earth's atmosphere over the Atlantic Ocean. According to some reports, parts of the rocket fell in Cte d'Ivoire.

In May 2021, Logsdon said that China owes an explanation.

It was common practice across the world for upper stages of rockets to burn up while reentering the atmosphere according to the Chinese foreign ministry spokesman.

According to the publication, local clearance notices have outlined drop zones for the rocket's boosters, but not for its body, which has fallen in the past.

The third module will be launched in October by China.