The International Space Station was slightly lighter last week.
The orbiting laboratory dumped a 2.9-ton (2.6-ton) pallet of used batteries on Thursday morning (March 11) – the most massive object it has ever discarded, NASA representative Leah Cheshier said. to Gizmodo.
The space debris is expected to fall back to Earth in two or four years, agencies wrote in an update last week. That update also said the pallet will burn “safely in the atmosphere,” but not everyone is convinced that’s the case.
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“This seems to me (haha, a pun depending on the circumstances) as dangerous. It seems big and dense so unlikely to burn completely,” astronomer and author Phil Plait, whose blog “Bad Astronomy” works on Syfy Wire, wrote on Twitter Thursday.
“Yes. On the other hand eg Tiangong-1 was 7500 kg [kilograms], much larger. But I would say, considering how dense EP9 is, it worries, albeit at the concern of care, ” answered astronomer and satellite Jonathan McDowell, which is based at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts.
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Tiangong-1 was China’s first prototype space station that hosted astronaut crews in 2012 and 2013. The school bus giant craft ended up crashing back to Earth over the South Pacific Ocean in April 2018.
EP9, an abbreviation of “Exposed Pallet 9”, is the recently discarded object. EP9 came to the station last year with a Japanese H-II Transfer Vehicle (HTV), as part of an effort to replace the lab’s old nickel-hydrogen batteries with new lithium-ion ones – an extended process that required a number of spacewalks over the past five years.
Previously, the old batteries were packed into the disposable HTV, which carried them until their destruction in the Earth’s atmosphere. But the October 2018 launch failure of a Soyuz rocket carrying NASA astronaut Nick Hague and cosmonaut Alexey Ovchinin disrupted this pattern, Spaceflight Now reported. (The Hague and Ovchinin finally landed safely, thanks to the launch-stop system of their Soyuz capsule.) And EP9 appeared on the ninth and final HTV, meaning it was left without a doomsday ride.
So space station managers decided to discard the battery pallet. Thursday morning ground controllers at NASA’s Johnson Space Center in Houston commanded the robot arm of the orbit lab’s 57.7-foot-long (17.6 meters) release EP9 into orbit, NASA officials wrote in the update.
The SUV-sized pallet has a lot of space junk company up there. According to the European Space Agency, researchers estimate that the Earth’s orbit is depleted by about 34,000 rubble objects at least 4 inches (10 centimeters) wide and 128 million pieces wide or larger.
Mike Wall is the author of “There“(Grand Central Publishing, 2018; illustrated by Karl Tate), a book about the search for a foreign life. Follow him on Twitter @michaeldwall. Follow us on Twitter @Spacedotcom or Facebook.