Station Flight Engineer Leopold Eyharts and Mission Specialist Hans Schlegel, both European Space Agency astronauts, opened the hatches to the new Columbus laboratory at 8:08 a.m. CST.
"This is a great moment and Hans and I are very proud to be here and to ingress for the first time the Columbus module," Eyharts said.
The crew remained ahead of schedule throughout the activation of Columbus, working inside to bring computers, ventilation and cooling systems online. While integrating the cooling system into that of the station's, temperature fluctuations caused the system to partially shutdown as a precaution. The system was brought back up and connected without incident later.
With the activation of the new lab, the Columbus Control Center in Oberpfaffenhofen, Germany, began supporting mission operations.
Late today, STS-122 Mission Specialists Rex Walheim and Schlegel will begin a camp out in the station's Quest Airlock in preparation for Wednesday's spacewalk. The spacewalk is scheduled to start at 8:35 a.m.
The crews will awaken at 3:45 a.m. Wednesday.