Williams ceremonially handed over the command of the International Space Station to fellow NASA astronaut Kevin Ford on the eve of her departure from the complex yesterday.
Williams along with Aki Hoshide of the Japan Aerospace Exploration Agency and Russian Soyuz Commander Yuri Malenchenko will return to earth today.
This exchange of command by Expedition Commander 33, Williams, who along with Malenchenko and Hoshide have lived on the space station since mid-July, heralds the beginning of Expedition 34.
"We have left the ship in good shape and am honoured to handed over to Kevin as we are going soon home and the ship is again in good hands," Williams said while handing over the command.
Ford, who has served as an Expedition 33 flight engineer since arriving at the station Oct 25, will become commander of Expedition 34 at the time the Soyuz TMA-05M carrying Williams, Hoshide and Malenchenko undocks from the station today at 5:26 pm EST for a landing in the steppe of Kazakhstan several hours later.
Their return will wrap up 127 days in space since their launch from Kazakhstan on July 15 last, including 125 days spent aboard the station.
Ford and his crewmates, Flight Engineers Oleg Novitskiy and Evgeny Tarelkin, will tend to the station as a three-man crew until the arrival of three additional Flight Engineers in December.
NASA astronaut Tom Marshburn, Canadian Space Agency astronaut Chris Hadfield, and Russian Federal Space Agency cosmonaut Roman Romanenko are scheduled to launch from the Baikonur Cosmodrome on Dec 19 and dock to the station two days later for a five-month stay.
Hadfield will become the first Canadian to command the station when Ford, Novitskiy and Tarelkin depart in March, marking the start of Expedition 35.