ERA (space station robot arm)

The European Robotic Arm (ERA) is a robotic arm to be attached to the Russian Segment of the International Space Station.

Major features and tasks

The intelligent space robot has several interesting features. Most prominent are its ability to 'walk' around the exterior of the station under its own control, hand-over-hand between pre-fixed basepoints and its ability to perform many tasks automatically or semi-automatically, thereby freeing its operators to do other work. Specific tasks of ERA include:

• Installation and deployment of solar arrays
• Replacement of solar arrays
• Inspection of the station
• Handling of (external) payloads
• Support of cosmonauts during space walks

The International Space Station already features one robotic arm, the Canadarm2 but because of the different types of basepoints and payload mounting units that arm can not be used on the Russian part of the ISS.

Developed for the European Space Agency (ESA) by the European space industry with Dutch Space as prime contractor and subcontractors in 8 countries, the robot arm will be launched by a Russian Proton rocket to be put to work in space by Russian cosmonauts. During the launch, ERA is attached to the Multipurpose Laboratory Module (MLM). This Russian module will also serve as home base for ERA during operations with the robot arm.

Control of ERA

Cosmonauts can control the robot from both inside as well as outside the space station. Control from inside the space station (Intra Vehicular Activity-Man Machine Interface (IVA-MMI)) uses a laptop which shows a model of the ERA and its surroundings. Control from outside the space station (Extra Vehicular Activity-Man Machine Interface (EVA-MMI)) uses a specially designed interface that can be used while in a spacesuit.

Arm components

• Two approximately 5 metres long, symmetrical arm sections made of carbon fibre ('limbs')
• Two identical gripper mechanisms (End Effectors 'EE') also capable of transferring data, power or mechanical actuation to payloads
• Two wrists with three joints each
• One elbow joint
• One central control computer within the arm ('ECC')
• Four camera and lighting units ('CLU')

Project status

• 2005 final qualification and delivery to the customer
  
• 2007 (November) planned launch to the International Space Station

Technical data

• Total length - 11.3 m
  
• Mass - 630 kg
  
• Maximum payload mass - 8000 kg
  
• Maximum speed of movement - 0.2 m/s
  
• Positioning accuracy - 3 mm