Crew Sleeps In, Prepares for Second Undocking Attempt

Expedition 24 Commander Alexander Skvortsov and Flight Engineers Tracy Caldwell Dyson and Mikhail Kornienko will re-enter the Soyuz TMA-18 spacecraft for a second undocking attempt at 10:02 p.m. EDT. The first undocking attempt Thursday was delayed after hooks failed to open and mission controllers in Moscow had not received the expected “hatch locked” signal from the Poisk module.

Though leak checks between the station and the Soyuz were good, commands to open hooks between the station and the Soyuz were not received. After waiting two orbits past the original undocking time, the departing crew members exited the Soyuz vehicle and spent the night in the International Space Station. The crew will wake up at 2 p.m. to begin its day and prepare for undocking.

Flight Engineer Fyodor Yurchikhin encountered some resistance Thursday night when closing the Poisk module hatch. He began troubleshooting the hatch when commands to open the hooks on the Poisk docking interface were not received. He discovered a loose star-shaped sprocket with two broken teeth behind the hatch cover.

To re-initiate the “hatch locked” signal, Yurchikhin installed jumper cables to bypass a component in the docking mechanism. This allowed the hooks on Poisk to be opened overnight which will allow the Soyuz TMA-18 to undock when hooks on the Soyuz are commanded open.

NASA TV coverage begins at 6:15 p.m. for hatch closure expected at 6:45 p.m. Coverage resumes at 9:45 p.m. for undocking, then again at midnight for the deorbit burn at 12:32 a.m. and landing at 1:21 a.m.