Progress M-66 was launched at 05:49 GMT on 10 February 2009, by a Soyuz-U carrier rocket flying from Site 31/6 at the Baikonur Cosmodrome. This was the first time Site 31 had been used for a Progress launch since Progress M-15 in 1992. The spacecraft docked with the Pirs module of the ISS at 07:18 GMT on 13 February. It undocked at 15:18 on 6 May, to make way for Progress M-02M. It was deorbited at 14:28:30 on 18 May following twelve days of free flight, during which it conducted experiments as part of the Plazma-Progress programme. Any debris from Progress M-66 that survived re-entry landed in the Pacific Ocean at around 15:14:45 GMT.
Progress M-66 delivered supplies to the International Space Station, including fuel, food and water for the crew, and equipment for conducting scientific research and establishing a 6-man crew capacity aboard the ISS. It also carried a new Orlan-MKspacesuit to replace one of the older Orlan-M suits previously used for EVAs from the station.
Payloads are separated by bullets ( · ), launches by pipes ( | ). Manned flights are indicated in bold text. Uncatalogued launch failures are listed in italics. Payloads deployed from other spacecraft are denoted in brackets.