The European Robotic Arm (ERA) is a robotic arm that is attached the Russian Orbital Segment (ROS) of the International Space Station. Launched to the ISS in July 2021; it is the first robotic arm that is able to work on the Russian Segment of the station. The arm supplements the two Russian Strela cargo cranes that were originally installed on the Pirs module, but were later moved to the docking compartment Poisk and Zarya module. The ERA was developed for the European Space Agency (ESA) by a number of European space companies. Airbus Defence and Space Netherlands (formerly Dutch Space) designed and assembled the arm and was the prime contractor; it worked along with subcontractors in 8 countries. In 2010, a spare elbow joint for the arm was launched preemptively, attached to Rassvet or Mini Research Module 1(MRM-1). The Nauka Module and Prichal module serves as home base for ERA; originally, the arm was going to be attached to the canceled Russian Research Module and later to the also canceled Science Power Platform. Technical characteristics The European Robotic arm consists of two 'limbs' that are symmetrical sections made primarily of carbon fibre reinforced plastic, and are approximately 5 m (16 ft) long. At either end of the arm are identical gripper mechanisms called End Effectors (EES), which the arm uses to hold onto the station, grab onto payloads, and to assist in EVA activities. In total there are seven motorized joints, three are located at each of the wrists, and allow for roll, yaw, and pitch movements, giving 7 degrees of freedom of movement. The elbow consists of one motorized joint, which is limited to pitch movements. The arm is controlled by the ERA Control Computer (ECC), or On Board Computer (OBC) which is located towards the elbow. The two limb design of the arm gives it the ability to 'walk' around the exterior of the Russian segment of the station under its own control, moving hand-over-hand between the pre-fixed base points. When fully extended the arm has a total length of 11.3 m (37 ft), and can reach and has 7 degrees of freedom. It has a mass of 630 kilograms (1,390 lb) and can hold a total payload mass of 8,000 kilograms (18,000 lb). The arm's tip can reach a speed of 0.1 metres per second (0.33 ft/s) and has an accuracy of 5 mm (0.20 in).