Tracy Caldwell Dyson, Alexander Skvortsov, Mikhail Kornienko Photo Credit/NASA
International Space Station astronauts Tracy Caldwell Dyson, Alexander Skvortsov and Mikhail Kornienko were unable to make their scheduled descent to Earth late Thursday because of a problem with the latching mechanism that secures their spacecraft to the orbiting laboratory.
The three fliers were tentatively scheduled to make a second attempt to depart in their Soyuz spacecraft on Friday at 10:02 p.m., EDT.
If successful, they will descend under parachute onto the plains of southern Kazakhstan, touching down on Saturday at 1:21 a.m., EDT, to end a 175-day mission.
The new landing strategy depends on a successful effort by station flight engineer Fyodor Yurchikhin to bypass what was believed to be a faulty micro switch in the Poisk docking module of the station’s Russian segment.
Skvortsov, Kornienko and Caldwell Dyson were originally scheduled to depart the station on Thursday night, touching down in the Central Asian landing done on Friday at 12:55 a.m., EDT
However, Yurchikhin encountered difficulties with a series of leak checks after the departing astronauts climbed aboard the Soyuz and closed the station and spacecraft hatches.
The troubleshooting delayed efforts by Russia’s Mission Control to open latches on the Poisk side of the docking mechanism with remote commands.
Skvortsov, the Soyuz commander, was unsuccessful as well when he attempted the commanding.
As three opportunities for the Soyuz to reach Kazakhstan came and went late Thursday, flight controllers in Moscow called off the landing operations for 24 hours.
Americans Doug Wheelock and Shannon Walker joined Yurchikhin in welcoming their weary colleagues back aboard the station, while flight controllers developed a repair plan.