Last week’s launch of the Chinese Long March 5B rocket was a success, for the most part.
The module is on its way to forming the first of 11 parts of the Chinese “Tianhe,” or “Heavenly Harmony,” space station — but the booster and tanks that launched the rocket are not where they’re supposed to be.
The boosters were supposed to fall to earth in a planned zone over the ocean, but inadvertently flew into the Earth’s orbit.
What goes up must come down, and this means the gigantic “core stage” (a term for the “backbone” of a rocket, including tanks and thrusters) — measuring 98 feet long and 16 feet wide — is now spinning out of control and poised to perform an uncontrolled reentry somewhere on Earth any day now, reports SpaceNews.
The event will mark one of the biggest human-made objects to perform an uncontrolled reentry in the history of space travel.
It’s not yet known why the launcher didn’t detach earlier over the ocean as planned, but a similar mistake happened to a Chinese rocket last year. That launcher reportedly finally fell into the Atlantic Ocean and onto West Africa, with debris possibly causing damage to villages in Cote d’Ivoire. No casualties were reported.
The core stage, which includes four side boosters, has a mass of around 21 tons.
Jonathan McDowell, Astronomer at the Center for Astrophysics, told SpaceNews that this is the fourth biggest ever incident of unplanned reentry of equipment.
“The Long March 5B core stage is seven times more massive than the Falcon 9 second stage that caused a lot of press attention a few weeks ago when it reentered above Seattle and dumped a couple of pressure tanks on Washington state,” McDowell told the publication.
“I think by current standards it’s unacceptable to let it reenter uncontrolled. Since 1990 nothing over 10 tons has been deliberately left in orbit to reenter uncontrolled,” he added.
The gigantic core stage, comparable in height to a 10-story building, may partially burn up on reentry, and it’s highly likely that debris from the booster will fall into the ocean or onto uninhabited areas. This leaves a small but real chance that the falling debris could threaten human lives and property.
The tanks and thrusters are currently spinning around the Earth at a rate of more than 4.4 miles per second, and are being monitored by a U.S. military radar, SpaceNews reports. The debris is flashing periodically, suggesting it’s tumbling and out of control. Surviving objects will fall vertically after deceleration and travel at terminal velocity, according to the publication.
The largest and most famous similar incident occurred in 1979 during the reentry of NASA’s 76-ton Skylab, which scattered debris across the Indian Ocean and Western Australia.
The Long March 5B booster’s orbital inclination of 41.5 degrees means the rocket body passes a little farther north than New York and as far south as New Zealand, so its reentry could occur anywhere around the globe between these latitudes.
A night time reentry, though, could make for spectacular viewing, as with a recent reentry of SpaceX’s Falcon 9 second stage, which was supposed to burn up over the Pacific Ocean but made an uncontrolled reentry over the Pacific Northwest. That incident produced a spectacular light show and dropped a pressure tank onto a farmer’s field, thankfully with no casualties.
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