At 4:27 p.m. EST, shuttle Atlantis and space station astronauts attached the Express Logistics Carrier -1 (ELC) to the Earth-facing side of the station’s left truss, or backbone. This is the first of two ELCs that will be installed on the station’s exterior during STS-129, providing easily-accessible spares to increase the longevity of the station.
The spare hardware stored on ELC-1 includes an Ammonia Tank Assembly, a Battery Charger Discharge Unit, a Control Moment Gyroscope, a station robotic arm Latching End Effector Unit, a Nitrogen Tank Assembly, a Plasma Contactor Unit, a Pump Module Assembly and a Passive Flight Releasable Attachment Mechanism.