After resolving problems with jammed bolts and sticky latches, Astronauts Kay Hire and Terry Virts - operating the space station's robot arm - moved the cupola into position for attachment at Tranquility's nadir port.
The cupola features six canted windows and a central overhead pane. While it will give station crews panoramic views of Earth, the primary goal is to give robot arm operators direct views of approaching unmanned cargo ships.
Initial attempts to detach the cupola from Tranquility's outboard port ran into a snag late Sunday, reports CBS News Space Analyst Bill Harwood, when at least two motorized bolts in the docking mechanism failed to disengage. The common berthing mechanism features four sets of motorized bolts.
"We had some initial challenges with unbolting the cupola from the port side and that was basically due to higher than expected running torques on the bolts," said shuttle Flight Director Kwatsi Alibaruho. "The cupola was bolted to the port side of node 3 on the ground so we just had to apply slightly higher torque than what we had expected, just by a few newton-meters."
The control software, in its default mode, was limited to applying a maximum torque of about 22 foot-pounds. When that didn't work, flight controllers sent commands to increase the torque and the bolts released at about 27 foot-pounds.
"So not a problem at all, just a minor adjustment we had to make," Alibaruho said.
He described the problem as "analogous to a situation where if you had a piece of equipment from the manufacturer that's got screws or bolts in it, they tend to be bolted down fairly tight. Once you release that initial torque ... the subsequent torque that you experience on those bolts tends to be a little bit less. Same type of situation, but no indication of off-nominal performance of the mechanism at all."
After the common berthing mechanism disengaged, astronauts Kay Hire and Terry Virts, operating the space station's robot arm, moved the cupola into position for attachment at Tranquility's nadir port.
Motorized bolts drove home in two stages, completing the attachment procedure at 1:31 a.m. The astronauts planned to work on outfitting the vestibule between Tranquility and the cupola later this morning, but they do not plan to open the hatch and go inside until overnight Monday.
Launch locks and protective window covers will be released during a spacewalk overnight Tuesday. Computer displays and equipment for controlling the station's robot arm will be moved into the cupola overnight Wednesday.
For more info:
CBS News space analyst Bill Harwood's "Space Place" updates
Space Shuttle Main Page (NASA)
International Space Station Main Page (NASA)
By AP Aerospace Writer Marcia Dunn