Update: Software patch fixes robot arm latching mechanism. (Hat tip reader jburn.)
Less that a week after astronauts did a spacewalk to install a new latching end effector on the end of one of the station’s robot arms NASA has decided to do another spacewalk to put the old “hand” back on.
Hints of an issue cropped up during the previous spacewalk when two of the six Expedition 54 astronauts—NASA’s Mark Vande Hei and Scott Tingle—replaced the end effector, called LEE-B, but ground teams were unable to communicate with the mechanism. “The spacewalking crew demated and remated the connectors and ground teams were able to power up the arm to an operational state on its secondary communications sting leaving the arm operational but without a redundant communications string,” a NASA statement reads.
After several days of troubleshooting, NASA and the Canadian Space Agency—which built the 57.7-foot (17.6-meter) long Canadarm2—said the decision was made to use the upcoming spacewalk to re-install the old LEE-B to restore the redundant capability with the arm. The space agency said if Canada and its robotics specialists find a way to solve the issue, the Jan. 29 spacewalk could be delayed.