(CNN) -- The spacewalk Tuesday was meant to replace a video camera and update cable connections to a module of the International Space Station.
However, the question every space buff wanted an answer to is: "What was that I just saw floating away?"
Two objects drifted away during astronauts Fyodor Yurchikhin and Mikhail Kornienko's six-hour assignment.
When the first one swam by, even NASA was befuddled as to what it was.
"Meanwhile here on the ground in Houston, flight controllers have been taking a look at the object seen floating away earlier in the spacewalk around 12:44 a.m. Central time," said the voice on the live NASA feed of the spacewalk.
"Still working to identify exactly what that object was, but they were able to determine that it does seem to have floated below the space station and it should not pose any sort of a problem for the space station as far as posing a debris threat."
Later, NASA spokesman Rob Navias said the object may have been a clamp used to attach cables, and it might have been left outside during a previous spacewalk.
An hour or so after the first fly-by, a small round object made its way into the darkness of space.
"Team here moving the cameras to follow another object that seems to have floated away," the NASA voice said this time. "A small round object that you can see in the middle of the screen here... Possibly a washer or something similar."
Navias said officials will do a photographic analysis to figure out what it was.
But, he said, "It's not unusual at all to have one or two objects float away during the course of a six-and-a-half hour procedure outside an orbiting space station."
The astronauts replaced a video camera that will monitor the docking of future Automated Transfer Vehicles, or supply ships.
They will then attach cables connecting the rest of the station to the Russian Rassvet research module.
CNN Radio's Matt Cherry contributed to this report.