The primary payload of STS-129 was the ExPRESS (Expedite the Processing of Experiments to the Space Station) Logistics Carrier (ELC-1) and the ELC-2.
Each steel framework has a mass capacity of 9,800 pounds (4,400 kg), with a volume of 30 m³ (total with spares, ELC-1: 13,850 pounds (6,280 kg) and ELC-2: 13,400 pounds (6,100 kg)).
The Goddard Space Flight Center served as the overall integrator for ELC-1 and ELC-2, with the addition of components manufactured by the Brazilian Space Agency.

The spare hardware stored on ELC-1 includes an Ammonia Tank Assembly, a Battery Charger Discharge Unit, a station
robotic arm Latching End Effector, a Control Moment Gyroscope, a Nitrogen Tank Assembly, a Pump Module, a Plasma Contactor Unit and two empty Passive Flight Releasable Attachment Mechanisms.

ELC-2 was launched with an oxygen-filled High Pressure Gas Tank (HPGT), a Cargo Transport Container (CTC-1), a Mobile Transporter Trailing Umbilical System Reel Assembly (MT TUS-RA), a Control Moment Gyroscope, a Nitrogen Tank Assembly, a Pump Module, MISSE attach hardware and one empty site for future payloads.

ELC-1 was installed on the Unpressurized Cargo Carrier Attachment System #2 (UCCAS 2) on the P3 (port side) segment of the main truss.
ELC-2 was installed on the Upper Outboard Payload Attach System on the S3 (Starboard Segment 3) of the main truss.
The primary payload of STS-129 was the ExPRESS (Expedite the Processing of Experiments to the Space Station) Logistics Carrier (ELC-1) and the ELC-2. Each steel framework has a mass capacity of 9,800 pounds (4,400 kg), with a volume of 30 m³ (total with spares, ELC-1: 13,850 pounds (6,280 kg) and ELC-2: 13,400 pounds (6,100 kg)). The Goddard Space Flight Center served as the overall integrator for ELC-1 and ELC-2, with the addition of components manufactured by the Brazilian Space Agency.
The spare hardware stored on ELC-1 includes an Ammonia Tank Assembly, a Battery Charger Discharge Unit, a station
robotic arm Latching End Effector, a Control Moment Gyroscope, a Nitrogen Tank Assembly, a Pump Module, a Plasma Contactor Unit and two empty Passive Flight Releasable Attachment Mechanisms.
ELC-2 was launched with an oxygen-filled High Pressure Gas Tank (HPGT), a Cargo Transport Container (CTC-1), a Mobile Transporter Trailing Umbilical System Reel Assembly (MT TUS-RA), a Control Moment Gyroscope, a Nitrogen Tank Assembly, a Pump Module, MISSE attach hardware and one empty site for future payloads.
ELC-1 was installed on the Unpressurized Cargo Carrier Attachment System #2 (UCCAS 2) on the P3 (port side) segment of the main truss. ELC-2 was installed on the Upper Outboard Payload Attach System on the S3 (Starboard Segment 3) of the main truss.
STS-129