An overhead crane in the Operations and Checkout Building lowers one of four gas tanks onto the Spacelab Logistics Double Pallet while workers help guide it. Part of the STS-104 payload, the storage tanks two gaseous oxygen and two gaseous nitrogen comprise the high pressure gas assembly that will be attached to the Joint Airlock Module during two spacewalks. The tanks will support future spacewalk operations from the Station and augment the Service Module gas resupply system