It took a little longer than expected, but by all accounts, Tuesday's spacewalk was a success.

At around 11:00 am ET (16:00 UTC), International Space Station (ISS) cosmonauts Oleg Kononenko and Sergei Prokopyev set out on a spacewalk expected to take about six hours. The purpose: examine a hole in the Soyuz capsule that some believe could have been an act of sabotage.

Five hours later, the pair finally got their first glimpse of the hole, and less than three hours after that, they were safely back within the ISS.

According to a report by the Associated Press, Kononenko and Sergei spent the first four hours of their ISS spacewalk simply making their way to the site of the hole, covering a distance of approximately 30 meters (100 feet).

Then, using a knife and long cutters, they dedicated more than an hour to removing a 10-by-10 inch (25 by 25 centimetre) patch of insulation on the exterior of the Soyuz. The purpose of the work was to expose the capsule's external hull.

Finally, the cosmonauts were able to see the hole, which measured about 2 millimeters (one-tenth of an inch) in diameter. Unlike the view of the hole from the interior of the Soyuz, which bore what looked to be drill marks near it, from the exterior, the hole just looked like a tiny black dot - no drill marks.

The cosmonauts collected samples from near the site of the hole before patching the insulation and returning to the space station, roughly eight hours after their ISS spacewalk began.

The samples Kononenko and Sergei collected will return to Earth aboard the Soyuz when it detaches from the ISS on December 19.

The part of the hull with the hole in it will detach from the capsule before it renters Earth's atmosphere. That means the samples, along with any photo and video evidence, may end up being the only clues investigators have to the origin of this mysterious hole in the ISS.

This article was originally published by Futurism. Read the original article.