With the undocking of a Russian Progress cargo ship from the International Space Station, only two spacecraft remain at the outpost – a rarity in an era of high visiting vehicle traffic.
Progress MS-03 undocked at 9:25 a.m. EST (14:25 GMT) Jan. 31, 2017, from the Pirs docking compartment on the Earth-facing side of the ISS after spending six months there.
The spacecraft launched July 16, 2016, from Baikonur Cosmodrome in Kazakhstan and docked two days later. It brought with it 2,500 kilograms of supplies, food, and equipment for then Expedition 48.
Since being unloaded of its cargo, it was reloaded with trash and other unneeded equipment. After undocking, once the vehicle was at a safe distance away from the outpost, the Progress conducted a deorbit burn at 12:34 p.m. EST (17:34 GMT) and burned up over the south Pacific Ocean some 45 minutes later.
The only vehicles remaining at the outpost are Soyuz MS-02 and Soyuz MS-03. The two crewed vehicles brought up three members each of the current Expedition 50 crew in October and November 2016, respectively.
There would have been another Progress spacecraft docked to the outpost had a launch anomaly not prevented it from achieving orbit. Progress MS-04 was lost Dec. 1, 2016, after the third stage of the Soyuz-U carrier rocket shut down prematurely. An investigation found the cause of the shutdown was a fire in the oxidizer pump in the third stage’s RD-0110 engine. The likely cause of the fire was the presence of debris inside the engine.
The next cargo ship scheduled to arrive at the outpost is currently expected to be SpaceX’s CRS-10 Dragon cargo ship. It currently has a no-earlier-than launch date of Feb. 14, 2017.
Just a week later, on Feb. 21, Progress MS-05 is expected to launch to the ISS from Baikonur.
Soyuz MS-02 is expected to leave the orbiting laboratory on Feb. 25 to bring Russian cosmonauts Sergey Ryzhikov and Andrei Borisenko, and NASA astronaut Shane Kimbrough back to Earth. They will be replaced by Russian cosmonaut Fyodor Yurchikhin and NASA astronaut Jack Fischer when Soyuz MS-04 launches on March 27, 2017.
Soyuz MS-03 and its associated crew – NASA astronaut Peggy Whitson, European Space Agency astronaut Thomas Pesquet and Russian cosmonaut Oleg Novitskiy – will remain at the space station until May 2017.
NOTE: While this article was written by Derek Richardson, it was originally published at SpaceFlight Insider. Feel free to head over there to read all the stuff they write about!