On May 12, 2017, the 200th ISS spacewalk was performed outside the International Space Station by astronauts Peggy Whitson (EV1) and Jack Fischer (EV2).

The US EVA-42 was shortened to 4 hours and 13 minutes due to a failure of one of two space suit umbilicals that keep the suits supplied on cooling and electricity while still inside ISS.
The Main tasks achieved:

  • Express Carrier Avionics Removal and replacement (ExPCA)
  • Alpha Magnetic Spectrometer (AMS-2) 1553 Terminator install
  • PMA-3 forward shield install
  • Secure multilayer insulation (MLI) on Japanese Remote Manipulator System (JRMS)

Worksites for US EVA-42

The astronauts headed towards the Starboard side of the station to conduct the first two main tasks on ELC-4 and AMS-2.

ExPCA removal and replacement

Peggy Whitson (EV1 red stripe suit) headed to the ELC-4 pallet to remove the failed ExPCA. This device resides on the forward facing side of the Express Logistics Carrier and acts as a central power distribution and data hub for all Orbital Replacement Units and experiments installed on each ELC. The replacement of the ExPCA is required to be completed before the next Dragon SpX-11 mission arrives in June which will bring a new payload.

Another view of Whitson removing the failed ExPCA

Jack Fischer (EV2 no stripe suit) is riding the robotic arm and is approaching Whitson to help removing the failed device.

The failed device was removed and a new ExPCA was installed. Once the old ExPCA was removed and put inside a temporary bag, both astronauts began the next tasks.

AMS02 1553 Terminator installation

Whitson made her way up the truss and climbed around AMS-2 to reach a connector panel to install the 1553 Feedback Terminator. This is a line tester to verify if the command and data path is still functional after sitting unused since the AMS-2 was installed on the STS-134 mission.

Whitson working on the connector

Secure MLI on JRMS

Jack Fischer handled the task to tying down a loose piece of Multilayer insulation (MLI) on the Japanese robotic arm boom to end effector interface.

PMA-3 Forward shield installation

Fischer is seen installing a forward shield to the base of the PMA-3.

Due to the shortened EVA, some original tasks have been differed for a later EVA.
The EVA tasks demonstrated here will not affect the ISS paper model.



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