Another International Space Station crew is saying goodbye: Expedition 36 Commander Pavel Vinogradov formally handed over control of the International Space Station on Monday in the traditional Change of Command Ceremony.

Flight Engineer Fyodor Yurchikhin, a member of Expedition 37, will not officially take command until the group undocks Tuesday evening, however.

Meanwhile, Expedition 36 members are engaged in last-minute preparations prior to their departure.

Cassidy, for example, has been collecting blood and urine samples for stowage inside the Human Research Facility's science freezer while Vinogradov and Flight Engineer Alexander Misurkin have been engaged in undocking preparations for the Soyuz spacecraft that will take them all home after five months aboard the orbiting lab.

Specifically, Vinogradov finalized packing gear inside the spacecraft while Misurkin practiced Soyuz descent operations, according to a NASA press release.

The crew, along with Expedition 37, has also been tasked with completing final undocking preparations and training for the arrival of the commercial spacecraft Cygnus on Sept. 22. Designed by the private company Orbital Sciences, the spacecraft will be launched atop an Antares rocket five days prior to its arrival. Nyberg and Parmitano are currently working to train for its rendezvous and berthing to the station's Harmony node.

Staying behind with Yurchikhin are Flight Engineers Karen Nyberg and Luca Parmitano, the three of whom have been aboard the station since late May and are scheduled to return in November.

These three will be joined by another team on Sept. 25. This group will include Flight Engineers Oleg Kotov, Mike Hopkins and Sergey Ryazanskiy.

The outgoing crew is scheduled to undock at 7:35 p.m. EDT with plans to land in Kazakhstan roughly three hours later. Landing coverage will begin Tuesday at 4:00 p.m. with the farewell and hatch closure.