|Mission type||ISS resupply|
|Mission duration||181 days|
|Spacecraft type||Progress-M s/n 355|
|Launch mass||5700 kg|
|Start of mission|
|Launch date||21 December 2005,|
|Launch site||Baikonur, Site 1/5|
|End of mission|
|Decay date||19 June 2006, 17:53:14 UTC|
|Epoch||21 December 2005|
|Docking with ISS|
|Docking date||23 December 2005,|
|Undocking date||19 June 2006, 14:06:01 UTC|
|Time docked||179 days|
(equipment and spare parts)
Progress M-55 (Russian: Прогресс М-55), identified by NASA as Progress 20P, was a Progress spacecraft used to resupply the International Space Station. It was a Progress-M 11F615A55 spacecraft, with the serial number 355.
Progress M-55 was launched by a Soyuz-U carrier rocket from Site 1/5 at the Baikonur Cosmodrome. Launch occurred at 18:38:20 UTC on 21 December 2005.
The spacecraft docked with the Pirs module at 19:46:18 UTC on 23 December 2005. It remained docked for almost 179 days before undocking at 14:06:01 UTC on 19 June 2006 to make way for Progress M-57. It was deorbited at 17:06:01 UTC on 19 June 2006. The spacecraft burned up in the atmosphere over the Pacific Ocean, with any remaining debris landing in the ocean at around 17:53:14 UTC.
Progress M-55 carried supplies to the International Space Station, including food, water and oxygen for the crew and equipment for conducting scientific research.