Earlier this year, Russia rocketed several satellites into space. They also deposited what was at the time believed to be a piece of space junk. With no declared orbit, the object was tracked by most of the world's space agencies, as well as amateur astronomers. Now, whispers are growing the so-called junk might actually be a "satellite killer."

The Russian name for satellite killer is "Istrebitel Sputnikov," and during the Cold War this pair of words would have been quickly recognized by U.S. security experts. It was a widely known that one of the main objectives of the Soviet Union (and most other world powers) was to launch anti-satellite weaponry. Most experts, however, assumed such ambitions died with the collapse of the empire.

But Russia's suspicious piece of space junk -- for which an orbital route was never publicly shared -- have some suggesting the Istrebitel Sputnikov mission was never abandoned.

"There's always confusion with these sort of things, because no one knows exactly what these satellites are up to," Robert Christy, a space expert and veteran amateur satellite tracker, told The Washington Post.

The U.S. Air Force keeps a database of all objects orbiting Earth -- except U.S. military crafts -- allowing people like Christy to track foreign satellites on their own time. As Christy and others saw, this piece of debris turned unidentified satellite, now known as Object 2014-28E, was able to link up with the remains of the rocket stage that had carried it into orbit. If it could track and link up with friendly pieces of debris, it could potentially cozy up next to an enemy object.

While it could simply be used to rendezvous with Russian satellites and perform repairs -- albeit anonymously -- it could also be used to more sinister ends, like to destroy or interfere with military communication satellites.

"Autonomous rendezvous by small satellites has always been considered a useful capability, for purposes of resupply, repair, inspection or even negation," Dr. James Oberg, a former NASA engineer, told The Moscow Times. "The fact that the recent Chinese and Russian experiments have been done with no official announcements, and appear independent of already existing [civilian] rendezvous systems, does suggest to me they are not for peaceful purposes."

If the speculation is true, it wouldn't actually be all that surprising, Christy says. He thinks Russia, China and the U.S. have all been developing similar technologies.

"In a nutshell, you've got all three countries doing the same thing," he said.