HOUSTON — Cosmonauts Fyodor Yurchikhin and Alexander Misurkin installed a troublesome telescope mount outside the International Space Station during an Aug. 22 spacewalk in which they also resecured a series of loose antenna covers.

It was their second excursion outside the orbiting science laboratory’s Russian segment in less than a week.

At just under 6 hr., the latest spacewalk followed a Russian record-setting 7-hr., 29-min. Aug. 16 outing in which the two cosmonauts extended solar power and Ethernet utility cables for the Nauka Multipurpose Laboratory Module (MLM).

After departing the Pirs airlock, Yurchikhin and Misurkin made their way to the Zvezda service module, where they removed a laser communications experiment installed two years ago. On a second attempt they managed to replace the communications apparatus with a 6-ft.-long workstation equipped with a bi-axial pointing platform for a new optical telescope.

When the cosmonauts were initially unable to align the platform properly, Russia’s Mission Control instructed the two men to return it to the airlock for further troubleshooting. That was followed just more than an hour later with instructions from the ground control team to proceed with the installation after all. The misalignment could be corrected with an adjustment of the yaw axis setting, they were informed.

The pointing device is scheduled to be fitted with an optical telescope system equipped with high- and medium-resolution cameras during a Russian spacewalk set for December.

Yurchikhin and Misurkin also tackled a task added to their spacewalk after a protective circular cover floated away from an antenna on the station’s Zvezda module on Aug. 19. The free-floating cover was spotted by the station’s six-member crew as it drifted away and reported to flight controllers in Houston and Moscow.

The cover’s source was traced to one of several WAL antennas positioned around the forward and aft ends of Zvezda to furnish close proximity communications during automated docking operations of unpiloted European Space Agency ATV resupply capsules.

The cosmonauts noted a missing cover from the forward portion of the module and found several others on either end loose. The spacewalkers used screwdrivers to resecure the remaining covers. However, their efforts were slowed by difficulties stabilizing their bodies against the outside of the module and interference in their communications.