Chinese rocket could cause damage equivalent to plane-crash on reentry
The massive 30-meter tall Long March 5B rocket stage that launched China's space station into low-Earth orbit is expected to reenter Earth's atmosphere sometime around May 8-9. The uncontrolled nature of the rocket's reentry makes it impossible to predict the impact point of the debris, with the "exact entry point into the Earth's atmosphere" being incalculable until within hours of reentry.
US Space Command expects uncontrolled reentry around May 8
"US Space Command is aware of and tracking the location of the Chinese Long March 5B in space, but its exact entry point into the Earth's atmosphere cannot be pinpointed until within hours of its reentry," said US Department of Defense spokesman Mike Howard.
Impact from several 100 kg pieces expected by weekend
The primary concern with the uncontrolled reentry is the Long March 5B's massive weight of 22 tons. Usually, space objects reentering Earth's atmosphere are vaporized by the ensuing friction and heat long before they reach the surface. However, Harvard-based astrophysicist Jonathan McDowell estimates several pieces as large as 100 kg could impact Earth. This could cause damage equivalent to a small aircraft crash.
Harvard astrophysicist downplays risk of Chinese space debris impact
"I don't think people should take precautions. The risk that there will be some damage or that it would hit someone is pretty small—not negligible, it could happen—but the risk that it will hit you is incredibly tiny," reassures McDowell.
Harvard astrophysicist tweets evidence of damage caused by previous reentry
Reports of a 12-m-long object crashing into the village of Mahounou in Cote d'Ivoire. It's directly on the CZ-5B reentry track, 2100 km downrange from the Space-Track reentry location. Possible that part of the stage could have sliced through the atmo that far (photo: Aminata24) pic.twitter.com/yMuyMFLfsv— Jonathan McDowell (@planet4589) May 12, 2020
Harvard University was indicted of infiltration by Chinese spies
While the Harvard astrophysicist summarily downplays the risk, it is important to note that China has been infiltrating US Universities by means of the Confucius Institute program, which also led to the arrest of a Harvard professor last year. Interestingly, McDowell had himself tweeted evidence showing 12-meter-long debris from the previous Chinese rocket stage causing damage in Cote d'Ivoire, West Africa.
Massive 7 tons of previous Chinese rocket survived 2017 reentry
The US Space Command tracks around 27,000 man-made space debris orbiting Earth. It expects reentry around May 8, but it's impossible to predict the point of impact due to its uncontrolled trajectory and environmental variables. Typically, between 20 and 40 percent of the rocket's dry mass is expected to survive, with seven tons of the previous Long March 5 rocket surviving the 2017 reentry.
Another instance of Chinese debris hit businesses, homes in Africa
While the 2017 reentry of the rocket landed in the Pacific Ocean, in May 2020 another one caused damage to West African businesses and homes. China is expected to make two additional space station launches using the same rocket. Such incidents are entirely avoidable by designing rockets to either return in a controlled manner or engineering them to be maneuvered on reentry.
Chinese rocket doesn't incorporate common safeguards preventing uncontrolled reentry
China's Long March 5B rocket wasn't built with any of the aforementioned good practices followed by space agencies across the world. That's also why the only incidences of large man-made space debris impacting Earth for the longest time have been these Chinese rockets. This has prompted calls for tightening rules governing rocket manufacture from members of the international space community.