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Japanese Experiment Module on the ISS

In its second phase, RRM is now moving on to demonstrate how a space robot can complete intermediate tasks required to replenish croygen in the instruments of "legacy" satellites: existing, orbiting spacecraft that were not designed to be serviced. Initial activities to demonstrate this on-orbit capability were completed with the aid of the original RRM tools and activity boards.

Experiments on RRM will also include evaluation of advanced solar cell technology. + Go to Phase 2 of the RRM Tasks

Schedule at a Glance

September 6-7, 2011
+ Launch Lock Removal and Vision

March 7-9 and June 19-22, 2012
+ Gas Fittings Removal, Parts I and II

January 14-25, 2013
+ Refueling
May 1-3 and 6-10, 2013
+ SMA cap removal
+ Screw Removal
+ Thermal Blanket Manipulation
August 4, 2013 and 2014
+ New RRM tools and taskboards launch to orbit
Summer 2013 - into 2015
+ RRM - Phase 2

What is RRM?

The Robotic Refueling Mission is an International Space Station demonstration that proves the tools, technologies and techniques to refuel and repair satellites in orbit - especially satellites not designed to be serviced.

RRM gives NASA and the emerging commercial satellite servicing industry the confidence to robotically refuel, repair and maintain satellites in both near and distant orbits - well beyond the reach of where humans can go today.

Why is NASA Testing Robotic Servicing Technologies?

Since 2009, SSCO has been aggressively advancing the robotic technologies for a notional free-flying servicer spacecraft that could access, repair and refuel satellites in geosynchronous Earth orbit, or GEO. RRM is a critical part of this technology development campaign.

Located about 22,000 miles above Earth, GEO is home to more than 400 satellites, many of which deliver such essential services as weather reports, cell phone communications, television broadcasts, government communications and air traffic management.

By developing robotic capabilities to repair and refuel GEO satellites, NASA hopes to add precious years of functional life to satellites and expand options for operators who face unexpected emergencies, tougher economic demands and aging fleets. NASA also hopes that RRM technologies will help boost the commercial satellite-servicing industry that is rapidly gaining momentum.

How RRM Works

RRM consists of the "RRM module" and four RRM Tools. The International Space Station's twin-armed Canadian "Dextre" robot acts as a skilled spacecraft refueling and servicing technician.

During operations, controllers on the ground remotely control Dextre to reach into the RRM module and pick up RRM tools. Dextre then goes to work on RRM's components and activity boards, demonstrating such servicing tasks such as cutting and peeling back protective thermal blankets, unscrewing caps, turning valves, and transferring fluid.

RRM Tools

Designed by NASA's Satellite Servicing Capabilities Office, the same team that developed astronaut tools for the Hubble Servicing Missions, the four unique RRM tools cut and manipulate wires, unscrew caps, open and close valves, and transfer fluid.


Now that the RRM is securely mounted onto the International Space Station, the operations team is dedicating the next two years to demonstrating robotic servicing and refueling and repair tasks using the RRM module and Dextre. See a breakdown of RRM's tasks.

The RRM Module

The RRM team at NASA's Goddard Space Flight Center broke down robotic servicing activities into distinct, testable tasks, then built the cube-shaped RRM module to contain the components, activity boards, and tools to practice them.

The module is about the size of a washing machine and weighs approximately 550 pounds, with dimensions of 33" by 43" by 45." RRM includes 0.45 gallon (1.7 liters) of ethanol to demonstrate fluid transfer in orbit. Protective thermal blankets, caps, valves, simulated fuel, and other spacecraft components allow the team to practice a wide range of satellite-servicing tasks.

RRM Photo [Above] Spacewalking astronauts successfully transferred the RRM module from the Atlantis shuttle cargo bay to an temporary platform on the ISS's Dextre robot. [full gallery]

What Makes RRM Unique?

First demo to test the robotic refueling of satellite interfaces not designed to be accessed or serviced. The Orbital Refueling System tested by astronaut Kathryn D. Sullivan during the 1984 STS-41-G shuttle flight and DARPA's robotic Orbital Express Mission were very successful, but had different objectives.

First use of the International Space Station's Dextre robot for technology research and development

Operations completely controlled from the ground

RRM tools execute activities at the end of more than 70 feet (21.34 meters) of combined Dextre and Canadarm2 robotics

Launch and Mounting on ISS

The shuttle Atlantis carried RRM to the International Space Station on July 8, 2011 during STS-135, the last shuttle mission. Spacewalking astronauts Mike Fossum and Ron Garan then transferred RRM onto a temporary platform on Dextre on July 12, 2011. RRM is the last payload an astronaut ever removed from a shuttle cargo bay.

On September 2, 2011, Canadarm2 and the Dextre robot transferred RRM to its permanent location on space station, the ExPRESS (Expedite the Processing of Experiments to the Space Station) Logistics Carrier-4.

Mission Operations

RRM operations are entirely remote controlled by flight controllers at NASA's Goddard Space Flight Center in Greenbelt, Md., Johnson Space Center in Houston, Marshall Space Flight Center in Huntsville, Ala., and the Canadian Space Agency's control center in St. Hubert, Quebec.

Development and Testing

Each RRM task requires a high level of robotic precision and demonstrates state-of-the-art technology, tools, and techniques. RRM maneuvers, tools and algorithms were tested and verified in the Goddard Satellite Servicing Center in Greenbelt, Maryland.


RRM is a joint effort between NASA and the Canadian Space Agency (CSA).