The Japanese Experiment Module (JEM), nicknamed Kibo (きぼう Kibō?, Hope), is a Japanese science module for the International Space Station (ISS) developed by JAXA. It is the largest single ISS module. The first two pieces of the module were launched on Space Shuttle missions STS-123 and STS-124. The third and final components were launched on STS-127.
Kibō consists of six major elements: 1) Pressurized Module (PM), 2) Exposed Facility (EF), 3) Experiment Logistics Module-Pressurized Section (ELM-PS), 4) Experiment Logistics Module-Exposed Section (ELM-ES), 5) Japanese Experiment Module Remote Manipulator System (JEMRMS), and 6) Inter-orbit Communication System (ICS).
The Pressurized Module (PM) is the core component connected to the port hatch of the Node 2 Module. It is cylindrical in shape and contains twenty-three International Standard Payload Racks (ISPRs), ten of which are dedicated to science experiments while the remaining 13 are dedicated to Kibo’s systems and storage. The racks are placed 6-6-6-5 along the four walls of the module. The end of the JEM-PM has an airlock and two window hatches. The Exposed Facility, Experiment Logistics Module and the Remote Manipulator System all connect to the pressurized module. Kibo is also the location for many of the press conferences that take place on board the station.
The Exposed Facility (EF), also known as "Terrace", is located outside the port cone of the PM (which is equipped with an airlock). The EF has 12 EFU (Exposed Facility Unit) ports that attach to PIU (Payload Interface Unit) connectors on EF-EEUs (EF-Equipment Exchange Units). All experiment payloads are fully exposed to the space environment. For proper functioning of these experiments, the payload requires an ORU (Orbital Replacement Unit) which consists of the EPS (Electrical Power System), CT (Communications & Tracking) and the TCS (Thermal Control System). Of the 12 ORUs, eight are replaceable by the JEMRMS while the other four are EVA-replaceable.