Crews on both ends would perform repairs and maintenance. It’s just a pizza drone on steroids, but instead of a spindly little hover-copter carrying a cardboard box it’s a steel tube the size of a sperm whale packed with all manner of goodies.
So, I guess they’ll be designed to limp home on back-up systems? If it’s a serious enough issue I guess a repair crew will boat or airlift out to them at sea?