The seat liners are key because the escape module -- if needed -- would land on the ground and the seats need to fit precisely to properly protect a returning astronaut or cosmonaut, according to Mark Ferring, the flight director for Alpha.

CNN: newcrew

Earlier Thursday, new Alpha commander Frank Culbertson and Russian flight engineers Vladimir Dezhurov and Mikhail Tyurin beamed down a message marking the one-thousandth day in space for the first component of the space station, the Russian-built Zarya module.

CNN: Spacewalkers hang experiments on Alpha

Prior to this shuttle delivery flight, there were sleeping quarters for only two Alpha residents.

CNN: Space station handover ceremony delayed