Rocket debris may crash land somewhere

CHINA LAUNCH

China’s latest launch of a huge rocket is, once again, raising alarm that the debris will crash into the Earth’s surface in an uncertain location and at great speed.

On Sunday afternoon local time, the Long March 5B blasted off from the Wenchang launch site on the southern island province of Hainan, carrying a solar-powered new lab, the Wentian experiment module, to be added to China’s Tiangong Space Station.

But the size of the heavylift rocket — it stands 53.6 metres tall and weighs 837,500 kilograms — and the risky design of its launch process have led experts to fear that some debris from its core stage could fail to burn up as it re-enters Earth’s atmosphere.

As with two previous launches, the rocket shed its empty 23-ton first stage in orbit, meaning that it will continue to loop the Earth over coming days as it gradually comes closer to landing. This flight path is difficult to predict because of fluctuations in the atmosphere caused by changes in solar activity.

Although experts consider the chances of debris hitting an inhabited area very low, many also believe China is taking an unnecessary risk. After the core stage of the last launch fell into the Indian Ocean, NASA Administrator Bill Nelson said China was “failing to meet responsible standards regarding their space debris,” including minimizing risks during reentry and being transparent about operations.

China rejects accusations of irresponsibility. In response to concerns about last year’s launch, the Chinese Foreign Ministry said that likelihood of damage was “extremely low.”

Before the launch, Jonathan Mcdowell, an astronomer at the Center for Astrophysics who closely tracks space launches, wrote on Twitter that he had hoped China would have adopted a new design to allow the core stage to be actively deorbited.

Late on Sunday, Mcdowell added that U.S. Space Command orbital data about two objects from the launch had confirmed that the core stage “remains in orbit and was not actively deorbited.”

Many scientists agree with China that the odds of debris causing serious damage are tiny. Yet an article published in the journal Nature Astronomy this month put the chance that, under current launch practices, someone would die or be injured from parts of a rocket making an uncontrolled reentry at 1 in 10 over the next decade.

Many believe launch designs like the Long March 5B’s are an unnecessary risk.

“Launch providers have access to technologies and mission designs today that could eliminate the need for most uncontrolled re-entries,” the authors wrote. They proposed global safety standards mandating controlled re-entry.

China’s program has achieved many victories over the past decade, including placing the Tiangong Space Station in orbit last year.