Dextre Rises

Dextre completed a lengthy space station apprenticeship Dec. 24. (Photo: NASA and CSA)

Canada’s Special Purpose Dexterous Manipulator, or Dextre, has been declared fit for duty aboard the International Space Station, following a lengthy apprenticeship that came to an end with a pre-Christmas demonstration of the muscular robot’s fine sense of touch.

The Dec. 23-24 exercise, carried out by U.S. and Canadian experts from NASA’s Mission Control Center in Houston, certified Dextre for the removal of external cargo from Japan’s second unmanned H-II Transfer Vehicle. The transport capsule, Kounotori, is scheduled to begin a seven-day journey to the station with a Jan. 20 launching from the Tanegashima Space Center.

Shuttle astronauts delivered the $209 million Dextre to the station in March 2008. The 12-foot tall robotic handyman, equipped with a pair of 11-foot-long arms, is designed to remove and replace batteries and cameras as well as perform other maintenance duties that would otherwise be assigned to spacewalking astronauts.

Dextre can operate as an extension of the station’s much longer Canadarm2, or while fitted to the Mobile Base System, a rail cart that moves along the station’s solar power truss.

During a Dec. 23-24 demonstration, Dextre was fitted to Canadarm 2. The longer mechanical limb was anchored to the MBS while Dextre was commanded to raise a 972-pound Cargo Transport Container from a spare parts platform on the station’s starboard solar truss. Using Arm 1, Dextre placed the CTC on a work platform on the robot at the end of the first day for an overnight stay.

On Dec. 24, Dextre completed the exercise by returning the CTC to the parts platform but at a new location. The shift in position was enough to clear room on the starboard truss for the Alpha Magnetic Spectrometer, which the crew of shuttle Endeavour’s STS 134 mission is to deliver in early April.

As Kounotori approaches the station on Jan. 27, station astronauts Catherine Coleman and Paulo Nespoli will grapple the cargo capsule with Canadarm2 and berth it to the Harmony node.

Canadarm2 will then extract an exposed equipment carrier from Kounotori and hand it off to Japan’s robot arm. The Japanese manipulator will temporarily store the carrier on the Kibo module’s “back porch” exposed facility.

Canadarm2 will then move away on the Mobile Base and return with Dextre. Dextre will remove two external spare parts from the exposed equipment carrier and relocate the new hardware as part of the Canadarm2/Mobile Base combination to the port side of the station’s truss for storage. Working solo, Canadarm2 will return the empty exposed cargo carrier to Kounotori.

The rise of the robots is crucial to future station operations.

The station’s NASA-led partnership is counting on the HTV, Europe’s ATV, Russia’s Progress and emerging U. S. commercial cargo transports to shoulder supply needs after NASA’s shuttle program is retired in 2011.

The HTV is the first of the unmanned craft equipped for the delivery of external spare parts.


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