It's an age-old question that is now getting a new space-age twist: What day is bin day?

So far, the process for disposing of trash on the International Space Station (ISS) has been to store it on board for months and wait for a cargo ship to arrive with new supplies. At that point, the festering mess diligently collected and stored by the astronauts and cosmonauts would be sent back to Earth on board the empty(er) ship.

The craft often used for these supply missions are, you might be surprised to learn, disposable. The Cygnus space freighters, once they are loaded up with trash, descend to Earth and burn up in our atmosphere, ship and all. Essentially, it's like if on Earth you gave your trash to the Amazon truck after they deliver your parcel, before setting that truck on fire. It is, to say the least, not the most environmentally friendly way of disposing of waste.

Now, there is a new method: sending a trash bag out of the new commercially funded airlock, which boasts five times the volume of the older airlock on the ISS. On Saturday, the new system was tested for the first time, successfully jettisoning approximately 78 kilograms (172 pounds) of waste from the ISS. 

This more direct route of disposing of trash has been done before in space, including on the Soviet space station Mir. With other ships able to run resupply missions to the ISS, the new method of disposal could lead to a more sustainable way of disposing of trash in space that doesn't involve burning a spaceship to a crisp.

“Waste collection in space has been a long-standing, yet not as publicly discussed, challenge aboard the ISS,” Cooper Read, Bishop Airlock program manager at Nanoracks, who worked on the airlock and trash disposal system, said in a press release.

“Four astronauts can generate up to 2,500 kg of trash per year, or about two trash cans per week. As we move into a time with more people living and working in space, this is a critical function just like it is for everyone at home.”