Astronauts Chris Cassidy and Luca Parmitano extended power cabling across the outside of the International Space Station’s U.S. segment for a future Russian lab, pre-staged utility lines and hardware to deal with potential cooling and power system failures and retrieved external science experiments during a NASA-sponsored July 9 spacewalk.

Some of the tasks initiated will be completed during a follow-on 6-to-7-hr. spacewalk by the same NASA and European Space Agency astronauts scheduled for July 16. The first outing by Cassidy and Parmitano concluded at 2:09 p.m. EDT and spanned 6 hr., 7 min. 

“Great work guys,” said NASA’s Mission Control.

Cassidy and Parmitano strung power cabling to the intersection of the station’s U.S. and Russian segments, where spacewalking cosmonauts will complete the extensions of NASA Ethernet as well as power links to a berthing port designated for Russia’s Nauka Multipurpose Laboratory Module (MLM) during an upcoming excursion.

The MLM, along with a European robot arm, awaits a Proton launch and unpiloted rendezvous and berthing with the ISS late this year.

Cosmonauts Fyodor Yurchikhin and Alexander Misurkin installed external clamps for U.S. power and Ethernet cable extensions during a June 24 spacewalk.

Cassidy and Parmitano will string Ethernet cabling across the U.S. segment to the intersection with the Russian segment during the July 16 excursion.

Cassidy provided U.S. power and data links to a power and data grapple fixture (PDGF) on the Russian Zarya module. The PDGF would serve as an anchor for Canada’s robot arm, where it could be controlled from the U.S. segment of the ISS to assist with future spacewalk activities on Russian modules.

The July 9 outing marked the first spacewalk by an Italian astronaut. The excursion was Cassidy’s fifth.

During the outing, Cassidy and Parmitano teamed to place grapple fixtures on thermal control system radiators that jut from the starboard and port sides of the station’s vaulting U.S. solar power truss. The fixtures were pre-staged to hasten efforts, if needed, to remove a failed radiator using the station’s Canadian robot arm.

Parmitano secured himself to the tip of the 58-ft.-long robot arm for the grapple bar installations. NASA astronaut Karen Nyberg maneuvered her colleague on the end of the mechanical limb from a control post inside the ISS.

The spacewalkers also started the installation of external jumper cabling on the solar power truss to permit astronauts inside the station to reconfigure the flow of solar power to control moment gyros, thermal control system hardware, Ku-band communications gear and other critical systems in response to possible external switching unit failures.

Cassidy and Parmitano replaced a failed Ku transceiver controller box and retrieved a failed external camera as well as a pair of U.S. Naval Research Laboratory materials exposure experiments. The samples of optics, electronic components and other candidate materials for spacecraft fabrication were deployed two years ago.

Parmitano applied an orbital debris shield across the docking mechanism once used by NASA’s shuttle fleet. The Pressurized Mating Adapter 2 docking port, last used in July 2011, will be configured for use by future U.S. commercial crew vehicles now in development under NASA Space Act agreements.