posted 10-05-2017 02:09 PM               

Astronauts give a 'hand' to robotic arm on spacewalk outside station

Two U.S. astronauts gave a Canadian robotic arm a hand Thursday (Oct. 5), replacing one of the manipulator's grappling ends during an almost seven-hour spacewalk.

Expedition 53 crewmates Randy Bresnik and Mark Vande Hei, both of NASA, worked outside the International Space Station to swap out a malfunctioning latching end effector (LEE) from the Canadarm2 robotic arm. The LEE — one of two on the 58-foot-long (17.6 meter) space station remote manipulator system (SSRMS) — is used to attach the arm to the orbiting laboratory and to grab hold of equipment or spacecraft in proximity to the outpost.

posted 10-10-2017 03:57 PM               

They also completed a variety of additional tasks, including replacing a smudged lens cover and removing two handrails from outside the tranquility module in preparation for a future wireless antenna installation.

This was the second of three spacewalks planned for October. Bresnik will also lead the next spacewalk Oct. 18 joined by flight engineer Joe Acaba to continue the lubrication of the new end effector and to replace another camera system on the Destiny lab.

posted 10-20-2017 02:06 PM               

The two astronauts installed a new camera system on the Canadarm2 robotic arm's latching end effector, an HD camera on the starboard truss of the station and replaced a fuse on the Dextre robotic arm extension.

The duo worked quickly and were able to complete several "get ahead" tasks. Acaba greased the new end effector on the robotic arm. Bresnik installed a new radiator grapple bar. Bresnik completed prep work for one of two spare pump modules on separate stowage platforms to enable easier access for potential robotic replacement tasks in the future. He nearly finished prep work on the second, but that work will be completed by future spacewalkers.

posted 01-23-2018 01:57 PM               

Vande Hei and Tingle temporarily secured the degraded LEE on external stowage platform-2 (ESP-2) and retrieved the former LEE A removed during a spacewalk in October and brought it inside for its later return to Earth aboard a SpaceX Dragon.

The spacewalk was the 206th in support of space station assembly and maintenance, the third in Vande Hei's career and the first for Tingle.

Vande Hei will venture outside the station again Jan. 29 with flight engineer Norishige Kanai of the Japan Aerospace Exploration Agency (JAXA) to stow a spare latching end effector removed from the robotic arm last October on to the station's mobile base system rail car for future use.

posted 01-26-2018 01:54 PM               

During a spacewalk on Jan. 23, 2018, Expedition 54 flight engineers Mark Vande Hei and Scott Tingle replaced a Latching End Effector (LEE-B) on the Canadarm2 robotic arm. An issue preventing the LEE from transitioning to an operational state on one of two redundant sets of communications strings was detected. 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 string leaving the arm operational but without a redundant communications string.

After extensive troubleshooting by teams from NASA and the Canadian Space Agency (CSA), the decision was made by space station managers to use the scheduled Jan. 29 spacewalk to reinstall the LEE removed on the Jan. 23 spacewalk to restore fully redundant capability to the robotic arm. CSA and its robotics specialists are continuing diagnostics over the weekend to gain additional insight. If data is obtained that could be used to solve the issue, Monday's spacewalk could be postponed.

posted 01-28-2018 10:14 AM               

International Space Station officials have postponed Monday's [Jan. 29] spacewalk to swap latching end effectors (LEEs) on the Canadarm2 robotic arm.

The decision was made after the Canadian Space Agency (CSA) and its robotics specialist team developed a diagnostics software patch confirming an anomaly noted in a primary communications string on the spare end effector installed during a prior spacewalk Jan. 23 was not hardware related, and can be corrected through the implementation of software. A confidence test verifying the software upgrade was successfully completed Saturday night.

During its initial power up after last Tuesday's spacewalk swap, the spare latching end effector did not communicate as expected on the primary string, but did so on its backup communications string. As a result, Monday's spacewalk by Mark Vande Hei of NASA and Norishige Kanai of the Japan Aerospace Exploration Agency (JAXA) was replanned to return the original latching end effector to the arm in place of the spare. But the software solution confirmed on Saturday will not require the spacewalkers to venture out on Monday.

The original spacewalk by Vande Hei and Kanai to bring an end effector inside the station removed from the arm during a spacewalk last October, and install the end effector removed last Tuesday on the mobile base system rail car on the station's truss, is expected to be executed by the two crew members in mid-February.

posted 02-16-2018 02:38 PM               

Expedition 54 Flight Engineers Mark Vande Hei of NASA and Norishige Kanai of the Japan Aerospace Exploration Agency completed a spacewalk on Friday (Feb. 16) lasting 5 hours and 57 minutes.

The two astronauts concluded their spacewalk at 12:57 p.m. EST (1757 GMT) with the repressurization of the Quest airlock.

The spacewalkers moved two Latching End Effector (LEE), or hands, for the Canadian-built robotic arm, Canadarm2. They moved one to a long-term storage location for future use as a spare part and brought the other inside the space station to be returned to Earth. It will be refurbished and later relaunched to the orbiting laboratory as a spare.

Running well ahead of the timeline, the two spacewalkers also conducted a number of get ahead tasks, including the lubrication of the inside of the LEE installed on the International Space Station's robotic arm during the Jan. 23 spacewalk.

They also positioned an interface tool for the Canadian Space Agency's robotic handyman Dextre, installed a grounding strap on a component of the LEE positioned on one end of the robotic arm, and adjusted a strut on a component on one of the station's spare parts platforms. That component is a flex hose rotary coupler that transfers liquid ammonia across a connecting point on the station's backbone to provide cooling for its systems.

It was the 208th spacewalk in support of International Space Station assembly and maintenance, the fourth in Vande Hei's career, and the first for Kanai, who became the fourth Japanese astronaut to walk in space.