An uncrewed Russian cargo ship will begin swapping parking spots at the International Space Station tonight (Oct. 20) in a move that will take just over a day to reach its new berth.
The Progress 78 spacecraft is scheduled to undock from Russia’s Poisk module at the station at 7:42 p.m. EDT (2342 GMT). There won’t be any coverage of the undocking on NASA Television, but you can watch it redock at its new port at the International Space Station on Thursday.
After undocking tonight, the Progress spacecraft will “station-keep” (that’s NASA-speak for hold its position) at a point about 120 miles (193 km) from the space station until for more than a day — 28 hours, 41 minutes to be exact — before redocking at the stations’ new Russian-built Nauka laboratory module Friday at 12:23 a.m. EDT (0423 GMT). NASA will carry coverage of the rendezvous and redocking starting at 11:30 p.m. EDT Thursday (0330 GMT Friday). All of these times are subject to change.
It’s unusual for a spacecraft to hold position for so long near the space station, but NASA said the waiting time would assist with the redocking procedure.
“The 24 hours for undocking/redocking is to allow Russian flight controllers to configure the systems on Nauka to receive the Progress,” NASA spokesperson Leah Cheshier told Space.com via email. “The vehicle backs away to a safe distance from the station while that work is going on.”
Additionally, Progress 78 will be able to do leak checks of the Nauka module propellant’s lines before the module fires its thrusters to perform “orientation control” of the station, NASA officials noted in a statement about the maneuver.
In late July, the Nauka module accidentally tilted the space station by about 540 degrees shortly after its own docking due to a software glitch. NASA has said the crew was in no danger at the time. (Yet another Russian spacecraft, a Soyuz MS-18 crew capsule that returned a film crew to Earth last week, briefly knocked the ISS off-orientation on Oct. 15. NASA and Roscosmos are looking into the root cause.)
The Progress 78 spacecraft will perform the docking without the help of the station’s current Expedition 66 crew, but Russian cosmonauts are standing by just in case they need to assist with the redocking, NASA said in a blog post about station operations.
“The station’s two cosmonauts, Flight Engineers Pyotr Dubrov and Anton Shkaplerov, are getting ready,” the blog post stated. “The duo practiced on the Zvezda service module’s tele-robotically operated rendezvous unit for the unlikely event they would have to manually redock the 78P.”
Progress 78 launched to the space station in late June and and arrived at the orbiting lab on July 1, when it docked at the Poisk module after a two-day trip. Its port switch comes just a week before another Russian cargo spacecraft, Progress 79, will depart Earth for the space station. The launch is scheduled to depart the Baikonur Cosmodrome in Kazakhstan for no earlier than 8 p.m. EDT Wednesday, Oct. 27 (0000 GMT or 5 a.m. local time Thursday, Oct. 28.) NASA will start its coverage about 15 minutes before launch.
Progress 79 will haul three tons of food, fuel and supplies to the space station for an expected docking at the aft port of the Zvezda service module at 9:34 p.m. EDT Friday, Oct. 29 (0134 GMT Saturday, Oct. 30). NASA plans its live coverage at 8:45 p.m. EDT Friday (0045 GMT Saturday).
Follow Elizabeth Howell on Twitter @howellspace. Follow us on Twitter @Spacedotcom and on Facebook.