As he ran 220 miles above the Earth on board the station, the runners circled Houston.
On Tuesday and Wednesday, McArthur, Flight Engineer Valery Tokarev and ground flight control teams rehearsed procedures for a rapid cabin air leak requiring station evacuation. Similar emergency procedures are regularly practiced by all station crews.
The crew is preparing for their second spacewalk. On Thursday, mission managers decided to delay the spacewalk from Feb. 2 to Feb. 3 to ease the crew's preparation schedule. Mission Control sent the crew detailed procedures for the spacewalk this week, and they reviewed them with experts on the ground. The crew began charging batteries and preparing the Pirs Docking Compartment airlock for the excursion. For the spacewalk, they will wear Russian Orlan-M spacesuits.
During the spacewalk, the crew will move a cargo boom adapter from one module to another; install a safety bolt into a cable cutter on the Mobile Transporter truss rail car; and deploy SuitSat, an old Orlan space suit equipped with an active amateur radio transmitter. SuitSat will remain in orbit for several weeks and allow contact with amateur radio operators on the ground.
Science operations this week included powering on the European Space Agency Protein Crystal Growth Monitoring by Digital Holographic Microscope for the International Space Station (PROMISS-4) experiment.
McArthur spent several hours setting up the Microgravity Science Glovebox and other support equipment early in the week. He began sample processing for the PROMISS experiment in the glove box on Thursday. The experiment will investigate the growth processes of proteins during weightless conditions using advanced imaging methods such as digital holography.
McArthur and Tokarev took time out from their duties on Friday to answer questions from students at the Kuss Middle School in Fall River, Mass.