View source for Dextre

{{Short description|Robotic arm on ISS}}
{{Use Canadian English|date=June 2020}}
{{Otheruses|Dexter (disambiguation)}}
{{Redirect-distinguish|SPDM|Spectral precision distance microscopy}}
{{Infobox spacecraft instrument
| Name = Special Purpose Dexterous Manipulator
| Image = Dextrereallyhasnohead.jpg
| Caption = Dextre, many of the ISS's Robotic arms and experiments, can be operated from Earth, performing tasks while the crew sleeps.
| Operator = [[NASA]]
| Manufacturer = [[MDA_(company)|MDA]]
| Type = [[telemanipulator]]
| Webpage = {{URL|http://www.asc-csa.gc.ca/eng/iss/dextre/}}
| Mass = {{cvt|3664|lb|order=flip}}
| Dimensions = {{cvt|3.5|m}} 
| Number = 1
| Spacecraft = [[International Space Station]]
| SC_Operator = {{Unbulleted list
  | '''[[US Orbital Segment|USOS]]:''' [[NASA]]
  | '''''[[Columbus (ISS module)|Columbus]]'':''' [[European Space Agency|ESA]]
  | '''''[[Kibo (ISS module)|Kibō]]'':''' [[JAXA]]
  | '''[[Russian Orbital Segment|ROS]]:''' [[Roscosmos]]
}}
| Launch = {{start date and age|March 11, 2008}}
| Rocket = [[Space Shuttle]]
| Launch_Site = [[Kennedy Space Center|Kennedy]] [[LC-39A]]
}}
[[File:S123 Dextre01.jpg|thumb|Dextre on the end of Canadarm2]]
[[File:Expedition 26 Dextre.jpg|thumb|Dextre, as photographed by an [[Expedition 26]] crew member]]
[[File:Dextre Expedition27.jpg|right|thumb|Dextre, as photographed by an [[Expedition 27]] crew member]]

'''Dextre''', also known as the '''Special Purpose Dexterous Manipulator''' ('''SPDM'''), is a two-armed robot, or [[telemanipulator]], which is part of the [[Mobile Servicing System]] on the [[International Space Station]] (ISS), and does repairs that would otherwise require astronauts to do [[Extra-vehicular activity|spacewalks]]. It was launched on March 11, 2008, on the mission [[STS-123]].

Dextre is a part of [[Canada]]'s contributions to the ISS and was named to represent its [[dexterity|dexterous]] nature. Dextre is the newest of three Canadian robotic arms used on the ISS, preceded by the [[Canadarm|Space Shuttle's Canadarm]] and the large [[Canadarm2]]. Dextre was designed and manufactured by [[MDA (company)|MDA]].<ref name=CWNS-2006-03-15>CanWest News Service, [http://www.canada.com/topics/news/world/story.html?id=0009b9b8-42d4-425a-bb40-7912db55e6cc '"Canada Hand" successfully installed'] {{webarchive|url=https://web.archive.org/web/20140326053412/http://www.canada.com/topics/news/world/story.html?id=0009b9b8-42d4-425a-bb40-7912db55e6cc |date=2014-03-26 }}, 15 March 2006</ref>

In the early morning of February 4, 2011, Dextre completed its first official assignment which consisted of unpacking two pieces for [[Kounotori 2]] while the on-board crew was sleeping.<ref name=Dextre-1>[http://www.nasa.gov/mission_pages/station/expeditions/expedition26/dextre_firstjob.html Dextre Successfully Completes Its First Official Job], [[NASA]], 2011-02-04</ref>

==Purpose==
Dextre is designed to handle and complete [[orbital replacement unit]]s:  Many spares are stored on the ISS and Dextre is able to carry them to and from worksites and install replacements when failures occur. Before Dextre arrived astronauts were required to perform space walks to carry out this long work.

==Structure==
Dextre resembles a gigantic torso fitted with two extremely agile, {{convert|3.5|m|ft|0}} arms. The total mass is about {{convert|3664|lb|kg|order=flip}}.<ref name=nasa-dextre/> The 3.5-metre-long body<ref name=nasa-dextre>{{cite web|url=http://www.nasa.gov/mission_pages/station/structure/elements/dextre.html |title=Dextre &#124; NASA |publisher=Nasa.gov |date=2013-10-18 |access-date=2016-05-30}}</ref> pivots at the "waist". The body has a Power Data [[grapple fixture]] at the 'head' end that can be grasped by the larger Space Station Arm, [[Canadarm2]] so that Dextre can be positioned at the various [[Orbital Replacement Unit]] (ORU) worksites around the Space Station. The other end of the body has a [[Latching End Effector]] virtually identical to that of Canadarm2, so that Dextre can also be attached to Space Station [[Grapple Fixture|grapple fixtures]] or the [[Mobile Base System]].

Dextre can also be operated whilst it is attached to the end of Canadarm2.<ref name=Apr2009/>

Each arm is somewhat like a shortened Canadarm2 (in that it has 7 joints) but is fixed to Dextre at one end.

At the end of Dextre's arms are [[ORU/Tool Changeout Mechanism]]s (OTCM). The OTCM has built-in grasping jaws, a retractable socket drive, a monochrome TV camera, lights, and an umbilical connector that can provide power, data, and video to/from a payload.<ref name=OTCM>{{cite web|author=Which term? |url=http://www.btb.termiumplus.gc.ca/tpv2alpha/alpha-eng.html?lang=eng&i=1&index=ent&srchtxt=uro%20tool%20changeout%20mechanism |title=uro tool changeout mechanism [1 record&#93; - TERMIUM Plus® — Search - TERMIUM Plus® | date=8 October 2009 |publisher=Btb.termiumplus.gc.ca |access-date=2016-05-30}}</ref>

Dextre moves one arm at a time, while one arm may hold onto the station (using specially provided standard H or Micro interfaces<ref name=SARAH2004/>{{rp|5.1}}) for stability and ease of control<ref name=SARAH2004/>{{rp|2.1}} the other is available to perform tasks.

==Tools==
The lower body of Dextre has a pair of orientable colour TV cameras with lights, a platform for stowing ORUs, and a tool holster. The tool holster is equipped with two '''Robotic Micro Conical Tools''' (RMCTs), which allow an arm to grasp additional types of ORU fixtures. The Socket Extension Tool (SET) extends the length of the grasping socket on an arm, and the Robotic Off-Set Tool (ROST) allows an arm to grasp difficult-to-reach targets.
<ref>{{cite web|author=Pete Harding |url=http://www.nasaspaceflight.com/2011/09/canadas-dextre-completes-marathon-week-robotics-ops-iss/ |title=Canada's Dextre Completes Marathon Week of Robotics Ops on ISS |publisher=NASASpaceFlight.com |date=2011-09-04 |access-date=2016-05-30}}</ref>

Several new tools were added as part of the 2011 [[Robotic Refueling Mission]]. A Wire Cutter, Safety Cap Removal Tool, EVR Nozzle Tool and a Multifunction Tool with several adapters.  These tools are not installed on Dextre but are used by Dextre when performing RRM operations.  The tools are not considered a part of Dextre's complement of tools and are stowed on the RRM platform.

In 2013 the H-II Transport Vehicle brought the RRM On-orbit Transfer Cage (ROTC), which is a sliding table within the Japanese airlock platform from which to retrieve and subsequently install new hardware.<ref>{{cite web |url=https://directory.eoportal.org/web/eoportal/satellite-missions/content/-/article/iss-utilisation-rrm |title=ISS Utilization: RRM - Satellite Missions - eoPortal Directory |publisher=Directory.eoportal.org |access-date=2016-05-30 |archive-date=2016-08-06 |archive-url=https://web.archive.org/web/20160806110839/https://directory.eoportal.org/web/eoportal/satellite-missions/content/-/article/iss-utilisation-rrm |url-status=dead }}</ref>

The [[Visual Inspection Poseable Invertebrate Robot]] (VIPIR), a borescope camera with a 34-inch long flexible tube, was added as part of the [[Robotic Refueling Mission]] — Phase 2. It was delivered to the station in 2014.<ref>{{cite web|url=http://ssco.gsfc.nasa.gov/rrm_phase2.html#hardware |title=Satellite Servicing Capabilities Office |publisher=Ssco.gsfc.nasa.gov |access-date=2016-05-30}}</ref>

In 2015, the International Space Station Robotic External Leak Locator (IRELL), developed by NASA, was delivered to the ISS. It includes a mass spectrometer and an ion vacuum pressure gauge to detect leaks of ammonia, one of the coolants used on the International Space Station.<ref>{{Cite web |title=International Space Station Robotic External Leak Locator |url=https://nexis.gsfc.nasa.gov/images/IRELL_Factsheet_010816.pdf |url-status=live |archive-url=https://web.archive.org/web/20240202214143/http://nexis.gsfc.nasa.gov/images/IRELL_Factsheet_010816.pdf |archive-date=2024-02-02 |access-date=2024-02-02 |website=NASA}}</ref>

===Future possibilities===
SARAH (Self-Adaptive Robotic Auxiliary Hand) is a three-fingered hand that is designed to attach to the end of Dextre's arm. It has not been delivered to the ISS.<ref name=SARAH2004>{{cite web|url=http://robot.gmc.ulaval.ca/docs/papers/conference/2004/Martin_Lussier-Desbiens_et-al_2004.pdf |title=Archived copy of SARAH Hand Used for Space Operations on STVF Robot|access-date=November 1, 2014 |url-status=dead |archive-url=https://web.archive.org/web/20141101065854/http://robot.gmc.ulaval.ca/docs/papers/conference/2004/Martin_Lussier-Desbiens_et-al_2004.pdf |archive-date=November 1, 2014 }}</ref>

==Design and delivery==
Dextre was designed and manufactured by [[MDA Space Missions]] (now [[MDA (company)|MDA]]) as part of the $200 million contracted by the [[Canadian Space Agency]], which will oversee its future operations and the necessary training of station crews.<ref>{{cite web|url=http://www.cbc.ca/news/technology/space-station-s-dextre-grounded-after-power-issue-discovered-1.758513?ref=rss |title=Space station's Dextre grounded after power issue discovered - Technology & Science - CBC News |publisher=Cbc.ca |access-date=2016-05-30}}</ref>

It completed all necessary testing and was delivered to the [[Kennedy Space Center]] (KSC) in Florida, in mid-June 2007. Once at KSC, it underwent flight verification testing followed by [[Space Shuttle|shuttle]] integration.

==Installation==
Dextre was launched to the ISS on March 11, 2008, aboard {{OV|105}} on mission [[STS-123]]. It "woke up" and activated heaters needed for keeping its joints and electronics warm after receiving power from the space station's Canadarm2 on March 14. During the mission's second spacewalk on March 16, spacewalking astronauts attached the two {{convert|3.35|m|adj=on}} arms to the robot's main body and further prepared the machine for its handyman job on the station. After the spacewalk, crew members hooked Dextre back up to the station's robotic arm to keep it warm and to allow NASA to perform tests to ensure all of Dextre's electronics were working properly. Later that day, the crew tested all of its joints and brakes.<ref name=cnn>{{cite news
 |url=http://edition.cnn.com/2008/TECH/space/03/16/space.shuttle.ap/index.html 
 |title=Spacewalkers resort to banging, pry bar 
 |date=March 16, 2008 
 |agency=Associated Press 
 |access-date=2008-03-17 
 |archive-url=https://web.archive.org/web/20080319091646/http://edition.cnn.com/2008/TECH/space/03/16/space.shuttle.ap/index.html 
 |archive-date=2008-03-19 
 |url-status=dead 
}}</ref> Astronauts finished outfitting the robot during a third spacewalk on March 17, 2008.<ref name="cnn080317">{{cite news|url=http://edition.cnn.com/2008/TECH/space/03/17/space.shuttle.ap/index.html |title=Astronauts outfit robot with tool belt, cameras |work=CNN.com |agency=Associated Press |date=2008-03-18 |access-date=2008-03-18 |archive-url=https://web.archive.org/web/20080319013550/http://edition.cnn.com/2008/TECH/space/03/17/space.shuttle.ap/index.html |archive-date=2008-03-19 |url-status=dead }}</ref>

==Operational use==
{{expand section|date=July 2021}}
After testing and trials, the first planned use was in the removal and replacement of an RPCM (Remote Power Control Module) in 2009.<ref name=Apr2009>[https://www.nasaspaceflight.com/2009/04/iss-preparing-debuts-canadas-dextre-operations-japans-htv/ ISS preparing for debuts of Canada's Dextre operations and Japan's HTV. Apr 2009]</ref>

In the early morning of February 4, 2011, Dextre completed its first official assignment which consisted of unpacking two pieces for [[Kounotori 2]] while the on-board crew was sleeping.<ref name=Dextre-1/>

As flight controllers have gained experience planning and executing Dextre operations, its use has become a more critical part of ISS maintenance. It is capable of removing and replacing (R&R) many ORUs on the ISS that would normally otherwise require costly and risky spacewalks to repair. Examples of items successfully R&R'd include RPCMs, an external camera, a Pump Flow Control Subassembly, and a Main Bus Switching Unit. <ref name=May2019>[https://www.spacedaily.com/reports/Robotics_used_to_restore_full_power_for_the_Space_Station_999.html Robotics used to restore full power for the Space Station, May 2019]</ref> It is also relied on heavily for extracting experiments and payloads from visiting vehicles, installing them to their final locations on the exterior of the ISS. Finally, Dextre supports scientific research and robotics development through experiments such as the Robotics External Leak Locator, Robotic Refueling Mission, and the [[Materials International Space Station Experiment]] Flight Facility (MISSE-FF).

== Other mentions ==

In early August 2004 [[NASA]] declared its intention to use Dextre (or a close copy of it) as the robotic component for the [[Hubble Space Telescope]] rescue mission. Months after awarding a contract to [[MDA (company)|MDA]] to provide an SPDM copy for the Hubble repair mission,<ref>[http://www.mdaspace.ca/ MDA Space Missions official site] {{webarchive|url=https://web.archive.org/web/20080318184913/http://www.mdaspace.ca/ |date=2008-03-18 }}</ref> NASA then canceled the mission in favour of flying a Shuttle mission to perform the repairs/upgrades. NASA cited excessive risks and new-found confidence in the [[Space Shuttle external tank]] as reasons for the cancellation.

Dextre was the subject of an April Fool's Day joke article on April 1, 2008, on NASA's APOD website.<ref>{{Cite APOD |date=1 April 2008 |title=New Space Station Robot Asks to be Called &quot;Dextre the Magnificent&quot; }}</ref>

Dextre was also featured in the new $5 Canadian Polymer bank note together with [[Mobile Servicing System|Canadarm2]], which Commander [[Chris Hadfield]] helped reveal aboard the International Space Station.<ref>[http://www.bankofcanada.ca/2013/04/press-releases/bank-canada-unveils-new-5-and-10-polymer-bank-notes/ Bank of Canada Unveils New $5 and $10 Polymer Bank Notes]</ref>

==See also==
{{Portal|Space}}
* [[Canadarm]], which was used on the [[Space Shuttle]]
* [[Mobile Servicing System]] (MSS), also known by its primary component the Canadarm2, used on the ISS
* [[European Robotic Arm]], A fourth robotic arm attached to the [[Russian Orbital Segment|ROS]], similar to the Mobile Servicing System
* The Japanese [[Japanese Remote Manipulator System|Remote Manipulator System]], used on the ISS JEM module [[Kibo (ISS module)|Kibo]]
* [[Strela (crane)|Strela]], a manually operated crane used on the [[Russian Orbital Segment|ROS]] which performs similar tasks as the Mobile Servicing System

==References==
{{reflist|33em}}

==External links==
{{Commons category}}
* [http://www.asc-csa.gc.ca/eng/iss/dextre/ Dextre, the International Space Station's Robotic Handyman] - Canadian Space Agency
* {{YouTube|TBrc5EMFd1I|Animation: Canadarm2 & Dextre remove CATS science experiment from SpaceX's Dragon and passes it to Japan's Remote Manipulator arm}}
* {{YouTube|yt3tf-f2RvQ|Animation: Canadarm2 & Dextre replacing a failed ammonia pump}}
{{MDA Space Missions|state=autocollapse}}
{{ISS modules}}
{{Orbital launches in 2008}}
{{Canadian Space Agency}}
{{Robotics}}

[[Category:Space robots]]
[[Category:Components of the International Space Station]]
[[Category:Space program of Canada]]
[[Category:Prototype robots]]
[[Category:Spacecraft launched in 2008]]
[[Category:Robotic manipulators]]
[[Category:2008 robots]]
[[Category:Robots of Canada]]