Robotic Refueling Mission Phase 2 (RRM-Phase 2) - 09.17.14
ISS Science for Everyone
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The Robotic Refueling Mission Phase 2 (RRM-Phase 2) tests the tools and techniques required to service and refuel satellites in space.
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Goddard Space Flight Center, Greenbelt, MD, United States
Sponsoring Space Agency
National Aeronautics and Space Administration (NASA)
Human Exploration and Operations Mission Directorate (HEOMD)
ISS Expedition Duration
March 2013 - Ongoing
Previous ISS Missions
RRM-P2 demonstrates the robotic technologies and techniques required to robotically replenish cryogen in legacy satellites in space: existing, orbiting spacecrafts that were not designed to be serviced. Activities include the intermediate steps leading to cryogen replenishment, but do not include actual cryogen transfer.
RRM-P2 continues the satellite-servicing demonstrations that began in the first phase of RRM operations: http://www.nasa.gov/mission_pages/station/research/experiments/778.html
New RRM hardware, delivered in August 2013 and summer 2014, is outfitting the existing RRM module for this new round of activities.
NASA's Robotic Refueling Mission (RRM) is an external International Space Station (ISS) investigation that demonstrates and tests the tools, technologies and techniques needed to robotically refuel and repair satellites in space, especially satellites that were not designed to be serviced. A joint effort between NASA and the Canadian Space Agency (CSA), RRM is the first in-orbit attempt to test robotic refueling and servicing techniques for spacecraft not built with in-orbit servicing in mind. Its first phase of demonstrations, conducted between September 2011 and May 2013, included a first-of-its-kind robotic refueling demonstration.
The RRM Phase 2 (RRM-P2) demonstrates how space robots can replenish cryogen (a type of refrigerant) in the instruments of “legacy” satellites: existing, orbiting spacecraft that were not designed to be serviced.
To perform these operations, two new modular task boards and the Visual Inspection Poseable Invertebrate Robot (VIPIR) tool are being delivered to the ISS and added onto the existing RRM module that was installed on the ISS ELC-4 in August 2011. The task boards are designed to mimic satellite interfaces that a robot would interact with during a servicing activity. The boards also include various mechanical adapters which the RRM tools pick up and use during operations to execute servicing tasks. The new VIPIR is a "boroscope" inspection tool that provides a set of eyes for internal satellite repair jobs.
With the help of the twin-armed Dextre robot, the newly installed RRM task boards, and the RRM tools, the RRM team works its way through intermediate steps leading to cryogen replenishment. After retrofitting valves with new hardware, peering into dark places with the aid of VIPIR and creating a pressure-tight seal, the RRM and Dextre duo stop short of actual cryogen transfer for this round of tasks.
RRM-P2 operations are scheduled to begin in 2014. Initial activities to demonstrate this in-orbit capability – cutting wires and removing caps – were completed in 2012 with the aid of the original RRM tools and activity boards.
The new RRM-P2 hardware is being delivered to the ISS in two shipments. In September 2013, the Japanese H-II Transfer Vehicle-4 delivers the RRM Task Board 3 and the RRM On-orbit Transfer Cage (ROTC), a novel device designed to facilitate the transfer of RRM hardware outside of the space station. A second shipment on the European Space Agency Automated Transfer Vehicle-5 in summer 2014 delivers a second task board and VIPIR to ISS.
Astronauts mount the ROTC on the sliding table within the Japanese airlock and install the RRM hardware onto the ROTC, giving the Canadian Dextre robot an easy platform from which to retrieve and subsequently install the new components on the RRM module. The Dextre robotic hardware transfer is entirely controlled from the ground without astronaut assistance.
The cutting-edge technologies RRM demonstrates could one day be used to extend the lives of many of the hundreds of satellites traveling the busy space highway of geosynchronous Earth orbit, or GEO. Located about 22,000 miles above Earth, this orbital path is home to more than 400 satellites, many of which beam communications, television and weather data to customers worldwide.
Servicing capabilities could greatly expand options for government and commercial fleet operators in the future, potentially delivering stakeholders significant savings in spacecraft replacement and launch costs.
A capability to fix and relocate "ailing" satellites also could help manage the growing orbital debris problem that threatens continued space operations, ultimately making space greener and more sustainable.
Refueling and repairing satellites in space would extend their lifetimes, allowing owners to avoid launching costly replacements. Some RRM technologies could potentially be adapted to fuel spacecraft robotically on the ground.
During the mission, Dextre uses unique RRM tools to demonstrate a suite of satellite-servicing tasks, including unscrewing caps and accessing valves, removing and installing coolant lines, and visual inspection of spacecraft components under a variety of lighting conditions. The investigation also continues to demonstrate general space robotic operations.
RRM-Phase 2 Mission Operations are being managed from Goddard Space Flight Center. Robotic operations are controlled by Johnson Space Center, with payload monitoring performed from Marshall Space Flight Center.
Controlled by robot operators on the ground, Dextre retrieves the new hardware from the ROTC within the Japanese airlock and installs them on the RRM module. Two components that launched with Phase 1, a task board and the Safety Cap Tool, are removed from the module by Dextre and brought back to the Japanese airlock.
Using the new task boards and the old and new RRM tools, the RRM team demonstrates the tools, technologies, and techniques needed for a robot to perform tasks leading up to cryogenic replenishment. No transfer of cryogen, however, occurs during this set of activities. RRM tools for Phase 2 activities include the Wire Cutter and Blanket Manipulation Tool, the Multifunction Tool, and the new VIPIR Tool.
Image Caption 4: Existing RRM Multi-Function Tool (MFT)
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