European Robotic Arm

In 2010, a spare elbow joint for the arm and ERA's Portable Workpost was launched preemptively, attached to Rassvet or Mini Research Module 1(MRM-1).

[3] 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.

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.

Since the ROS uses different base points than the US Orbital Segment, the arm is unable to operate and access the other parts of the station.

[4] The EES consists of two Basic End Effectors (BEE) that connect to Base Points (BP) and Grapple Fixtures (GF).

[5] At the same time, the second end effector provides mechanical and electrical power to the grappled objects, and allows for data transfer.

Both of the end effectors are also capable of measuring torques/forces as well as contain a Camera and Lighting Unit (CLU) which aids in the control of the arm; an additional two CLUs are located on both limbs.

The application layer contains the high level command, mission plan, and event handling; the service layer contains the main robot motion control loops, motion related checks and image processing; together the AL and SL constitute the Application software (ASW).

The main CPU is a Temic designed ERC32 with 10 MHz clock, addressing 1.5 megabytes (Mb) of memory, as well as 32 kilobytes (Kb) of ROM.

[7] Located in each wrist and in the elbow, there is one microprocessor that takes care of the bus communication, local inhibits, and safety checks, as well as general housekeeping.

Using a torque/force sensor inside the end effectors, the ECC actively controls the arm's pose to keep the contact forces within tight limits.

Also on the console is the emergency stop button which, when pressed, will activate brakes in all joints and at the same time send a command to the Russian Segment to switch the whole arm off.

[10] Control from inside the space station is done by the Intra Vehicular Activity-Man Machine Interface (IVA-MMI), using a laptop, which shows a computer generated model of the ERA and its surroundings.

It functioned similarly to the Canadarm on the American Space Shuttle; being located within the cargo bay and controlled from the cockpit.

[12][9] With the shift to the ISS, the ESA and Roscosmos signed a cooperation agreement about the ERA in 1996, and would have the arm be a part of the canceled Russian Research Module, with development beginning in 1998.

[13] Following the cancellation of the Research Module ERA was moved to the Russian Science Power Platform, which would have become the base of operations for the arm.

In March of that year the Weightless Environment Test model "WET" underwent acceptance activities at the Gagarin Cosmonaut Training Centre.

The following year, ESA signed a contract with Airbus Defence and Space Netherlands to prepare the ERA to launch on a Proton rocket in November 2007.

In 2010, the Space Shuttle Atlantis delivered Rassvet (Mini Research Module 1) on STS-132, (as a part of an agreement with NASA) to the station, which included a spare elbow joint with 2 limbs to allow the actual to repair itself while in orbit and the Portable Work Platform for the ERA, which will be used during EVAs.

The first of these, originally scheduled for January 2022 but were delayed to 18 April 2022, will involve the removal of external covers and launch restraints, following which the ERA will be activated and undergo an In-Orbit Validation.

All necessary checks and assembly of ERA were originally planned to occur within 6 months of Nauka docking with the ISS but have since been pushed back.

Communication links between the ISS, Russian Mission Control Centre, and the European Robotic Arm Support center in the Netherlands were successfully tested.

[30] Initial checks also included the validation of the external Man Machine Interface and that the ERA can communicate properly while connected to a base point located on the outside of the ISS.

[17] On 18 April the first in a series of space walks was conducted by cosmonauts Oleg Artemyev and Denis Matveev; taking seven hours to complete.

During the EVA the EVA-MMI was installed the outside of the station and subsequently conducted a diagnostic test to confirm that the panel was receiving power and in good working order.

Following the completion of the installation of the EVA-MMI the cosmonauts removed covers from the arm's grapple fixtures and base plates, as well as on the elbow.

[17] The final two stages of preparation of the ERA for full operation was checking its motion performance as well the procession of data on the ground.

[11][14] To complement the training astronauts receive on the ground, The Refresher Trainer provides the crew on board the ISS with the capability to rehearse their missions.

[40] An additional arm is fixed on the Japanese Experiment Module, the Remote Manipulator System (JEM-RMS), also known as Kibo.

The Canadarm2 has to be controlled by a human, whether that be by astronauts on board the ISS or be a ground team at the CSA headquarters or NASA[43] The ERA is less powerful and smaller than the Canadarm2 as it is not required to dock spacecraft with the station.

A grapple fixture used by the European Robotic Arm, located on the Rassvet Mini-Research Module 1 (MRM1) of the International Space Station. This fixture, along with others allows for the European Robotic Arm to grapple and move around the station.
Control and data interfaces of ERA
An illustration of the Science Power Platform, including the ERA. Prior to its cancellation the ERA would have launched on the SSP module.
The Multipurpose Laboratory Module (MLM) Nauka after it successfully docked to the International Space Station. The European Robotic Arm is loaded on the module awaiting deployment.
ERA spare elbow on MRM-1 below the Russian flag and Energia symbol covered under thermal blankets
MLM outfittings on MRM-1 including the black ERA portable workpost on the left near the docking port
The flight model of the European Robotic Arm well on display during a media day at Airbus Defence and Space Netherlands on 5 April 2006. During the day, the flight model was set up in a similar configuration to how it would be configured for launch.
The European robotic arm is pictured extending out from the Nauka multipurpose laboratory module during a mobility test several days after Roscosmos cosmonauts Oleg Artemyev and Denis Matveev activated the ERA during a seven-hour and 42-minute spacewalk.