located on one side of the center module segment. Each of the two berthing ports on Destiny contains a hatch. Both hatches are normally open, and remain open unless a situation arises requiring a module to be isolated. Each hatch has a window. The hatches can be opened or closed from either side. The hatches have a pressure interlock feature, which prevents the hatch from being opened if there is a negative pressure across the hatch (higher pressure on the outside of the hatch). The hatch openings are a square-like six sided shape - which is associated to that module. Destiny has a optically pure, telescope-quality glass window located in an open rack bay used primarily for Earth science observations. Station crewmembers use very high quality video and still cameras at the window to record Earth's changing landscapes. A window shutter protects the window from potential micrometeoroid and orbital debris strikes during the life of the ISS. The crew manually opens the shutter to use the window. Imagery captured from Destinys window has given geologists and meteorologists the chance to study floods, avalanches, fires and ocean events such as plankton blooms in a way never seen before, as well as given international scientists the opportunity to study features such as glaciers, coral reefs, urban growth and wild fires. Specifications Length: Diameter: Mass: Pressurized Volume: Equipment As with the European and Japanese laboratories of the station, payloads inside Destiny are configured around International Standard Payload Racks (ISPRs), that can be removed or reconfigured for various experiments and equipment. Made out of a graphite composite shell, each rack weighs about , and is about high, and wide. The eight rack bays are equipped with curtains that provide around of temporary stowage space when not occupied by experiments. Destiny arrived at the station pre-configured with five racks housing electrical and life support systems that provide electrical power, cooling water, air revitalization, and temperature and humidity control. Seven additional racks were flown to Destiny in the Leonardo Multi-Purpose Logistics Module by STS-102, and ten more were delivered on subsequent missions. Destiny can hold up to 13 payload racks with experiments in human life science, materials research, Earth observations and commercial applications. The laboratory has a total of 24 racks inside the laboratory, six on each side. Internal to the laboratory are racks, rack stand-offs, and vestibule jumpers. The lab racks house the system hardware