The strange hole that was found months ago in the Soyuz spacecraft attached to the International Space Station continues to be a major focus for Russian space agency Roscosmos. When it was first discovered, it was thought to be damage from a tiny space rock, but it quickly became clear that it was actually a hole that had been drilled prior to the spacecraft ever leaving Earth.

Russia was quick to boldly claim that it was likely intentional sabotage, but Roscosmos hasn’t made any definitive announcement regarding when the hole was drilled or by whom. To aid in its investigation, Russia conducted a planned spacewalk yesterday so that cosmonauts could inspect the damage from outside and gather samples. It’s becoming an unprecedented “whodunnit,” and it’s happening in space.

The spacewalk, which took nearly eight full hours, tasked cosmonauts Oleg Kononenko and Sergei Prokopyev with removing an outer layer of protective insulation from the area around the hole before taking samples of the damaged area. That material will be brought back to Earth when the spacecraft returns home and investigators will apparently use it in their search for the truth.

After removing the insulation and snapping images and recording video of the damage, the cosmonauts installed fresh insulation over the top of the already-patched hole.

Unlike any spacewalk before it, the extravehicular activity the cosmonauts embarked on was extremely challenging. As reported by Russian news organization TASS, performing the investigation and sample collection was difficult because it’s in an area of the ship where crew members wouldn’t normally venture. With no handles or railings, the men had to move slowly and methodically.

Russia hopes to conclusively determine whether the hole was made in space or on Earth, though up to this point all word out of the country has suggested that it was created during the manufacturing process.