Crew equipment on board the orbiter is stowed in lockers with insertable trays. The trays can be adapted to accommodate a wide variety of soft goods, loose equipment and food. The lockers are interchangeable and attach to the orbiter with crew fittings. The lockers can be removed or installed in flight by the crew members. There are two sizes of trays: a half-size tray (two of which fit inside a locker) and a full-size tray. Approximately 150 cubic feet of stowage space is available, almost 95 percent of it on the middeck.

The lockers are made of either epoxy- or polyimide-coated Kevlar honeycomb material joined at the corners with aluminum channels. Inside dimensions are approximately 10 by 17 by 20 inches. The honeycomb material is approximately 0.25 of an inch thick and was chosen for its strength and light weight. The lockers contain about 2 cubic feet of space and can hold up to 60 pounds.

Dividers are used in the trays to provide a friction fit for zero-g retention. This will reduce the necessity for the straps, bags, Velcro snaps and other cumbersome attach devices previously used. Soft containers will be used in orbiter spaces too small for the fixed lockers.

The trays are packed with gear so that no item covers another type of gear. This method of packing will reduce the confusion usually associated with finding loose equipment and maintaining a record of the equipment.

Stowage areas in the orbiter crew compartment are located in the forward flight deck, the aft flight deck, the middeck, the equipment bay and the airlock module.

In the aft flight deck, stowage lockers are located below the rear payload control panels in the center of the deck. Container modules can be mounted to the right and left of the payload control station. Since these side containers are interchangeable, they may not be carried on every mission, depending on any payload-unique installed electronic gear.

In the middeck, container modules can be inserted in the forward avionics bay. Provisions for 42 containers are available in this area. In addition, there is an area to the right side of the airlock module where nine containers can be attached.

Harness stowage bags stowed in a middeck stowage locker or airlock are used on orbit to stow flight crew members' launch equipment, such as helmets, harnesses, boots and waste/trash materials.