CAPE CANAVERAL, Fla. -- NASA believes that a small object spotted floating outside the International Space Station Thursday is likely an identification tag from an external power or data cable, according to a report.

Astronaut Ed Lu spotted the object outside the window of the U.S. laboratory and took pictures of it, Local 6 News partner Florida Today reported.

Ground controllers reportedly observed Lu's photos and e-mailed images of possible matches to the astronaut for identification.

Agency spokesman Kyle Herring said that Lu selected the example resembling one of the many numbered tags used to identify power and data cables in outside the space station, The Houston Chronicle reported.

The loss of the tag is not considered a safety hazard or an operational problem, according to an official.

Lu and cosmonaut Yuri Malenchenko are in the middle of a six-month stay aboard the station.

They are expected to be relieved in October by another two-man crew, who will fly on a Russian Soyuz to the station.