NASA - Expedite the Processing of Experiments to the Space Station Logistics Carrier

NASA - National Aeronautics and Space Administration. Fact Sheet. OpNom: The EXpedite the PRocessing of Experiments to Space Station (EXPRESS) Logistics Carrier (ELC) is a platform designed to support external payloads mounted to the International Space Station (ISS) starboard and port trusses with either deep space or Earth views. Gene Cook, Johnson Space Center, Houston, TX, United States. Facility Developer(s) Goddard Space Flight Center, Greenbelt, MD, United States. National Aeronautics and Space Administration (NASA) Previous ISS Missions. Cargo space is a precious commodity onboard the space shuttle, and the EXpedite the PRocessing of Experiments to Space Station (EXPRESS) Logistics Carrier (ELC) is capable of carrying as many as 12 fully integrated payloads, Orbital Replacement Units, or loads of outfitting cargo to the International Space Station (ISS) in the space shuttle cargo bay. Five ELCs are in the ISS baseline and will be mounted on starboard truss 3 (S3) and port truss 3 (P3) through a series of robotic maneuvers that will move them from the space shuttle cargo bay to attachment sites on the ISS. The EXpedite the PRocessing of Experiments to the Space Station (EXPRESS) Logistics Carrier (ELC) is carried in the space shuttle cargo bay to the International Space Station (ISS). Five ELCs will be delivered to the ISS before the space shuttle's retirement in 2010; four ELCs will be attached to starboard truss 3 (S3), and one ELC will be attached to port truss 3 (P3). When the ELC is attached to the S3 and P3 sites, a variety of views—toward the zenith (deep space) or nadir (Earth) with a combination of ram (forward) and wake (aft) pointing—allow many viewing opportunities. Each ELC can accommodate 12 Flight Releasable Attachment Mechanism (FRAM)-based cargos, including two payload attach sites with full avionics accommodation. The mass capacity for an ELC is 4,445 kg (9,800 lb) with a volume of 30 m 3 . The ISS provides power to the ELCs through two 3-kW, 120-Vdc feeds at the ISS-to-ELC interface. The ELC power distribution module converts the 120-Vdc power to 120-Vdc and 28-Vdc power. Both power voltages are provided to each payload attach site by separate buses. The 120-Vdc power is also provided to other cargo attach sites. After ELC installation, it may take up to 4 hours for the power to be connected. At the ISS-to-ELC interface, there are two types of data ports: the High-Rate Data Link (HRDL) and the Low-Rate Data Link (LRDL). The HRDL uses fiber optics to provide ISS-to-ELC communication. At the interface between the ELC avionics module and the payload interface, there are three data ports: HRDL, LRDL, and Medium-Rate Data Link (MRDL, Ethernet). For uplink MRDL, Ethernet is used; the ELC avionics module will convert the MRDL signal from HRDL interface and deliver it to each payload attach site. The transmission rate between the ELC avionics module and the payload attach site is no higher than 10 Mbps. Downlink MRDL and HRDL signals will be transmitted from payload attach site to the ELC avionics module by separated buses. The ELC avionics module will combine these two signals for transmission to the ISS using the HRDL interface. The HRDL rate for downlink service to the ground is no higher than 95 Mbps (megabits per second). The LRDL is used for a two-way data and command link between the ELC and each payload attach site via the ELC avionics module at maximum rate of 1 Mbps. External camera ports are also available for the ELC payloads. At least 14 camera port locations along the trusses can be used for payload observation. Ground Based Results Publications. Artist's representation of the EXpedite the PRocessing of Experiments to Space Station (EXPRESS) Logistics Carrier (ELC) mounted to the port truss (P3) on the International Space Station (ISS). (Image provided by NASA) + View Larger Image. Artist's representation of the EXpedite the PRocessing of Experiments to Space Station (EXPRESS) Logistics Carrier (ELC) mounted to the starboard truss (S3) on the International Space Station (ISS). (Image provided by NASA) + View Larger Image. Computer generated image of the completed International Space Station showing external facilities and platforms. Image courtesy of NASA. + View Larger Image. NASA Image: S130E010286 - Expedition 22 / STS-130 joint operations photograph of ELC 2 taken during a survey of the S3 Truss. + View Larger Image. Schematic showing the configuration of items on ELC 1 Outboard facing side during the increment 33/34 timeframe. Image courtesy of NASA. + View Larger Image. Computer model of a fully loaded ELC platform. Image courtesy of NASA. + View Larger Image.