Aboard Leonardo were six Resupply Stowage Racks, four Resupply Stowage Platforms, and two new scientific experiment racks for the station's U.S. laboratory Destiny. The two new science racks (EXPRESS Racks 4 and 5) added further science capability to the station. EXPRESS stands for Expedite the Processing of Experiments to the Space Station. EXPRESS Rack 4 weighs and EXPRESS Rack 5 weighs . The empty weight of each EXPRESS rack is about . EXPRESS Racks 1 and 2A were delivered aboard the Raffaello cargo module during STS-100/6A in April 2001. EXPRESS Rack 3 was brought to the station during STS-111 in 2002. The racks were manufactured at the Space Station Processing Facility.