HTV-X2

HTV-X2 is the second flight of JAXA’s upgraded resupply freighter — the successor to the original Kounotori vehicle that flew nine missions between 2009 and 2020. It lifts off from Tanegashima on an H3 rocket and carries about 5,800 kg of cargo, of which roughly a third is in an unpressurised section bolted to the outside of the spacecraft. The biggest single mass any single freighter brings to the Station this year.

On the external pallet are two replacement lithium-ion battery units, part of the long-running effort to swap out the Station’s original nickel-hydrogen power packs. The Canadian robotic arm reaches into HTV-X’s exposed bay, lifts the units out one at a time, and walks them across the truss to the worksites. The empty vehicle then unberths, reboosts the Station’s orbit on its way out, and burns up over the Pacific weeks later.