The International Space Station (ISS) has to occasionally jettison various items as it orbits Earth 250 miles up.
Sometimes it’s just general trash that accumulates on the space-based laboratory over time, while on other occasions it could include parts of the station that are no longer needed.
On Thursday, March 11, mission controllers in Houston commanded the space station’s Canadarm2 robotic arm to jettison an external pallet containing old nickel-hydrogen batteries into Earth orbit.
The nickel-hydrogen batteries were once used for the ISS’s power system but have since been replaced with newer lithium-ion batteries featuring improved power capacity, smaller size, and lighter mass.
Fortunately, the pallet and the batteries inside it won’t remain as space junk indefinitely (there’s enough of that already orbiting our planet), as the whole lot will burn up when it enters Earth’s atmosphere in several years’ time.
NASA astronaut Mike Hopkins captured several images of Thursday’s release process from inside SpaceX’s Crew Dragon spacecraft, which is currently docked at the space station after transporting Hopkins and three other astronauts to the ISS in November 2020.
Crew Dragon Resilience watched as @NASA ground controllers released a pallet that will eventually burn up in the atmosphere. pic.twitter.com/pgQCx1ocSJ
— Mike Hopkins (@Astro_illini) March 11, 2021
It’s not always a robotic arm that releases objects from the space station. Sometimes it’s the astronauts themselves who execute the process.
In January, for example, NASA astronaut Victor Glover jettisoned a decommissioned science antenna cover during his first-ever spacewalk, with the process captured on video and posted online.
Jettisoning something from the ISS is actually a very delicate procedure requiring a carefully calculated maneuver to send it on its way. This ensures the item enters an orbit that will prevent it from crashing into the space station later on.
There’s a busy weekend ahead for several members of the current seven-person crew with final preparations now underway for a spacewalk on Saturday, March 13. NASA astronauts Mike Hopkins and Victor Glover will conduct the extravehicular activity (EVA) — as spacewalks are officially known — spending nearly seven hours carrying out a range of maintenance work and upgrades on the exterior of the orbiting outpost. You can watch the spacewalk live via NASA TV.