A Long March 5B rocket lifts off from the the Wenchang launch site on China’s southern Hainan … [+]
China successfully launched one of its big Long March 5B rockets to space on Sunday, sending the new Wentian laboratory module to be attached to the Tiangong Space Station.
But the big booster that carried the lab to orbit now appears set to make an “uncontrolled re-entry” in the not-too-distant future.
More simply put, the 23-ton, 10-story tall rocket stage is gradually being pulled back towards the surface of our planet by gravity as it circles Earth above us. Eventually, it will be pulled all the way back down and there’s no way of steering it to ensure safe disposal in the ocean or somewhere else remote.
Astronomer Jonathan McDowell confirmed on Twitter that the first stage made it all the way to orbit. This means that, unless there has been an unreported redesign of the booster, it is now just drifting and waiting to fall back to Earth. The rocket’s engines can not be re-ignited, so there is no way to steer it to a safer re-entry trajectory.
McDowell adds that the rocket will most likely break up and “past experience shows that a bunch of 30-metre-long metal fragments will end up crashing into the ground at a few hundred km/hr.”
This is becoming a disturbingly common practice for China’s space program. We saw that same thing happen with the same type of rocket in May of last year. That booster does seem to have wound up in the ocean. The first launch of China’s biggest rocket in 2020 rained debris on western Africa but did not cause any injuries.
And just a few months ago, in April, a smaller rocket from the same Long March family made an uncontrolled and unplanned re-entry, dropped debris over parts of India.
It is very difficult to predict where the remains of an out-of-control object in the clutches of gravity will end up. Roughly, the debris will end up reaching the surface somewhere between and 41.5 degrees north and south of the equator. That means some huge cities like Los Angeles, New York and Sydney aren’t guaranteed to be safe.
Still the odds of any human being injured by falling space junk are vanishingly small. As far as we know, it’s never happened in the six decades we’ve been shooting things into orbit.
But there’s now more things in orbit than ever before and one recent study warns there’s a ten percent chance of an uncontrolled re-entry causing a casualty over a ten-year period.
