Most of the time when the International Space Station needs to get rid of the trash, the crew just stuff unneeded items into a used cargo capsule. When it gets full, they drop it into the atmosphere where the capsule burns up. At least, this is what usually happens. Just like how garbage trucks occasionally leave items behind, the astronauts sometimes have waste that is too big to go in that outbound cargo craft turned trash can.

For the ISS, Thursday, March 11, was the big garbage day. A three-ton pallet of old nickel hydrogen batteries had been hanging around, unused, on the outside of the station, and the time to finally throw them out had come.

These batteries had provided the station with power, but, like all batteries, the day came when they needed to be replaced. They got set aside rather than thrown out because three tons of batteries is a bit big for most of the cargo vehicles.

Astronauts using the ISS’ Canadarm released the pallet of old batteries from the side of the station and sent it on its way. These discarded batteries are the largest object ever jettisoned from the Space Station. The pallet is expected to re-enter the atmosphere in a few years. Until then, it will be yet another object for new fleets of low orbiting commercial spacecraft such as CubeSats and SpaceX’s Starlinks to maneuver around as they raise themselves into their operational orbit.

In general, this is not how batteries should be disposed of people.

For the longest time, the astronauts had done exactly what so many of us do; they had kept the dead batteries hanging around in a box, or in their case on a pallet.

This unceremonious jettison was necessary because a Japanese HTV spacecraft that could have brought the batteries down in a controlled destructive re-entry was unavailable. The ascent abort of Soyuz MS-10 in 2018 caused a ripple-effect that delayed the schedule for replacing the old nickel batteries with new lithium ion batteries. This resulted in one of the HTV spacecraft returning empty, leaving an extra set of old batteries on the station.

Prior to this pallet of old batteries, the largest thing that had been released from the ISS was a 635-kilogram tank of ammonia from an interim ISS cooling system that was released during an EVA in 2007.

While this jettison will make life more complex for other spacecraft for the next few years, this does have the same eventual outcome that an HTV spacecraft would have allowed: the batteries will burn-up in the upper atmosphere where it can’t affect life or pollute our world.

Don’t try this method of battery disposal unless you are in space.

More Information

Gizmodo article

Houston Chronicle article