Experts scramble to pinpoint crash site of uncontrollable 21-tonne Chinese rocket
Governments and scientists are scrambling to pinpoint exactly where the remains of a 100-foot Chinese rocket will crash into Earth this week.
The out-of-control Long March-5B Y2 rocket is falling back to Earth after delivering the first module of China’s upcoming space station Tianhe into orbit.
However, Chinese authorities aren’t able to bring the rocket down safely into the ocean. Instead, debris from its reentry could hit populated areas.
Daily updates on where the rocket will hit are being posted on Space Track, but a US Department of Defense official has said the exact location won’t be known ‘until within hours of its reentry’.
It’s looking likely the rocket will crash back down on Saturday, May 8.
Twisted, scorched bits of metal could land anywhere along the rocket’s flight path – including New York, Beijing or Madrid. The flight path does not seem to take it over the UK.
‘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, which is expected around May 8,’ said DoD spokesperson Mike Howard.
Holger Krag, head of the Space Safety Programme Office for the European Space Agency, told Space News, there is an average amount of mass of about 100 tons re-entering in an uncontrolled way per year.
‘This relates to about 50-60 individual events per year,’ he said. ‘It is always difficult to assess the amount of surviving mass and number of fragments without knowing the design of the object, but a reasonable “rule-of-thumb” is about 20-40% of the original dry mass.’
Meanwhile, Jonathan McDowell, an astronomer who tracks objects orbiting Earth, said the previous Long March 5B launch saw the fourth biggest uncontrolled re-entry ever in May last year.
At the time, it splashed down in the waters off the west coast of Mauritania just off the coast of West Africa, after flying over Los Angeles and New York City.
Speaking ‘Last time they launched a Long March 5B rocket they ended up with big long rods of metal flying through the sky and damaging several buildings in the Ivory Coast,’ McDowell told The Guardian.
‘Most of it burned up, but there were these enormous pieces of metal that hit the ground. We are very lucky no one was hurt.’
The launch was the first of 11 missions necessary to construct and provision the station and send up a three-person crew by the end of next year.
At least 12 astronauts are training to fly to and live in the station, including veterans of previous flights, newcomers and women, with the first crewed mission, Shenzhou-12, expected to be launched by June.
When completed by late 2022, the t-shaped Chinese Space Station, called ‘Heavenly Harmony’, is expected to weigh about 66 tonnes.
This will make it considerably smaller than the International Space Station, which launched its first module in 1998.
Tianhe will have a docking port and will also be able to connect with a powerful Chinese space satellite. Theoretically, it could be expanded to as many as six modules. The station is designed to operate for at least 10 years.
If the remains of the rocket were to cause any damage, China could potentially be liable.
‘International law sets out a compensation regime that would apply in many circumstances of damage on Earth, as well as when satellites collide in space,’ explains Steven Freeland, professorial fellow, Bond University/emeritus professor of international law at Western Sydney University.
‘The 1972 Liability Convention, a UN treaty, imposes liability on ‘launching states’ for damage caused by their space objects, which includes an absolute liability regime when they crash to Earth as debris.
‘In the case of the Long March 5B, this would impose potential liability on China. The treaty has only been invoked once before (for the Cosmos 954 incident) and therefore may not be regarded as a powerful disincentive.’
‘However, it is likely to come into play in the future in a more crowded space environment, and with more uncontrolled reentries. Of course, this legal framework applies only after the damage occurs.’