Despite heightening tensions here on Earth, the United States has long enjoyed a cooperative relationship with Russia when it comes to space.  In fact, all five space fairing organizations involved in orbital operations within the International Space Station maintain open lines of communication regarding everything that reaches the man-made island of habitability high above the barrier between Earth and the heavens… that is, until now.

On Thursday, Russia aborted the launch of a Progress MS-07 rocket from the famed Baikonur Cosmodrome in Kazakstan that was chock full of important supplies for the six crew members currently living aboard the ISS.  The launch itself was expected to be normal enough, as was the cargo inside, but when Russia released photographs of the rocket as they prepared for launch, NASA experts noticed something they’d never seen before: an unusual instrument mounted on the exterior front section of the ship.

Mounting a never-before-seen device to the nose of one of these craft isn’t unheard of, and Russia actually attached a different gadget, the Otrazhenie-5 (reflection) device, to a similar launch in 2014.  That experiment used an optical sensor to measure atmospheric phenomena, and ultimately burned up on reentry as the capsule returned to earth.  What makes Thursday’s launch so different, however, is how Russia responded when asked about it by NASA.

Russia was aware of the photographs of the ship, including the strange device attached to it, seemingly suggesting that they aren’t trying to keep it a secret, but when contacted by NASA, Roscosmos (Russia’s space agency) replied only that it was a scientific instrument intended for a one-time trip… and refused to offer any further details.

It’s worth addressing how unusual that sort of thing is, after all, Russia isn’t particularly well-known for their transparency.  That’s what makes this situation so unusual, because this is literally the first reported time any of the nations involved in the International Space Station have done such a thing in its entire 19 year run.

The instrument potentially could be gathering information that could aid in the development of new ballistic missile platforms, or even for ground based missile detection devices, but there’s no current evidence to support the idea that the mystery experiment is military in nature, aside from Russia’s unwillingness to discuss it.

Of course, Russia’s decision to bend the rules regarding international cooperation on the ISS isn’t without precedent.  Just a few months ago, the United States also made an unusual, and unaddressed, move by sending one of its newest spy satellites to within just a few kilometers of the space station on multiple orbits.  The close proximity of the spy satellite to the ISS wasn’t announced by the U.S. government, but was identified by amateur satellite trackers that had been following the secretive satellite since its public deployment by SpaceX earlier in the year.

Because the satellite passed within only four kilometers of the space station, doing so by accident could only be characterized as gross negligence – which seems unlikely to be the case in one of the country’s newest and most advanced spy satellites.  If instead it was done deliberately, it may have been as a part of calibrating sensors against a known distance body, or perhaps, to investigate something on the space station itself.