[ufoolme]

Anyone know why they didn’t just keep it around, surely having a few old batteries and a bit more shielding around the ISS might have come in handy? Was it risky to keep them around or did the extra weight (even in a basically weightless environment) come at a cost to maintaining orbit?

[Leo_Verto]

The ISS has to regularly perform station keeping, i.e. it has to expand fuel to raise its continuously decaying orbit. Any additional weight would increase the fuel required for this.