During a nearly eight-hour spacewalk, two Russian cosmonauts used a knife to peel back thermal insulation in order to inspect an area of the Soyuz MS-09 spacecraft where a small leak occurred and was repaired earlier in the year.
In August 2018, a minor leak was detected aboard the International Space Station. The source of the slow depressurization event was traced to the Orbital Module of Soyuz MS-09. Using an epoxy, the crew of then Expedition 56 quickly sealed the microcrack, which was described as about 2 millimeters wide.
It was ultimately deduced that the hole was created on the ground during spacecraft processing. However, exactly when it occurred and who did it has not been publicly determined. Roscosmos boss Dmitry Rogozin described it as a “technological error,” caused by a specialist.
Regardless, with the hole sealed—and no signs of leakage since August—it poses no risk to the trio that will return to Earth using Soyuz MS-09: Russian cosmonaut Sergey Prokopyev, European Space Agency astronaut Alexander Gerst and NASA astronaut Serena Aunon-Chancellor. The microcrack was in the Orbital Module, which is not designed to re-enter Earth’s atmosphere intact. Following a deorbit burn, the three sections of the Soyuz spacecraft—the Orbital Module, Descent Module and Service Module—are separated with only the Descent Module with its human occupants making it to the ground safely.
Nonetheless, Russian engineers wanted imagery of the hole from the outside of the spacecraft with samples of any residue collected for analysis on Earth.
Beginning at about 15:59 UTC Dec. 11, 2018, Expedition 57 Russian cosmonauts Oleg Kononenko and Prokopyev exited the airlock hatch on the Pirs docking compartment to begin Russian EVA-45a.
Kononenko was wearing a spacesuit with red stripes and designated extravehicular crew member 1—the lead spacewalker—while Prokopyev wore a spacesuit with blue stripes and was designated EV2. It was their fourth and second spacewalks, respectively.
Using a Strela telescoping arm, the cosmonauts were able to access the Orbital Module of Soyuz MS-09, which was attached to the Earth-facing port of the space station’s Rassvet module.
In dramatic fashion, Kononenko used a knife and other sharp objects to slice into the thermal insulation blanket to get to the micrometeoroid orbital debris shield on the exterior of the Soyuz. Pieces of material could be seen floating away from the incision site as he worked to expose the metallic hull of the spacecraft.
“Honestly, I can’t look at that,” Prokopyev joked as he helped steady Kononenko. “It’s my vehicle, Oleg.”
The act of cutting into the material was likely difficult as every time Kononenko tried to slice or tear the material, he would subsequently push or pull himself away, despite having handrails and a foot restraint.
Eventually, enough of the thermal blanket was peeled away to get to the debris shield. Kononenko then used a pair of shears to cut through in order to see the small black dot of epoxy that made its way through the hole.
Kononenko was then instructed to use forceps to grab a piece of the epoxy to bring back to Earth for analysis.
The plan was originally to cover the exposed area with a new thermal blanket. However, Mission Control in Moscow decided that because the vehicle was returning to Earth next week, it was not necessary. Additionally, the spacewalk was already running long.
Kononenko and Prokopyev cleaned up the area as best they could before using the Strela arm to move away from the Soyuz. According to NASA, before returning back to Pirs, science experiments on the exterior of the Rassvet module were retrieved to bring back inside.
When the two returned to the inside of Pirs, its hatch was closed, officially ending the spacewalk at 11:44 UTC for a total of 7 hours, 45 minutes.
Soyuz MS-09 is set to depart the space station with Prokopyev, Gerst and Aunon-Chancellor at 01:42 UTC Dec. 20. Landing is expected several hours later in Kazakhstan. They will leave behind Kononenko, NASA astronaut Anne McClain and Canadian Space Agency astronaut David Saint-Jacques, who are expected to remain in orbit until June 2019.
Video Credit: SciNews