Russia tests satellite that can chase other spacecraft

Russia may be testing a satellite that can chase down other orbiting spacecraft — possibly to destroy or disable them.

The Kosmos 2499 was launched on Christmas Day last year as part of what seemed like a routine mission to add communications satellites to an existing constellation, BBC News reports.

Previous such launches had carried a trio of spacecraft but on this occasion a fourth object was released into orbit.

In May 2014, the Russian government told the United Nations that the fourth object was another satellite.

Satellite observers watched it use engines to perform a series of unusual manoeuvres in space that changed its orbit.

Then, on November 9, the satellite chased down part of the rocket that originally launched it into orbit, coming within a few tens of metres.

"I think this mission is a test, and you test these things with your own satellites, because if you do it with other peoples' they get upset," satellite observer Robert Christy told BBC.

"The Americans don't want bits of Russian hardware sitting alongside their satellites."

Such satellite-chasing technology could be used as an anti-satellite weapon. But it could also be valuable to civilian satellite operators, allowing them to repair or refuel malfunctioning spacecraft on-orbit.

This year, both America and China have carried out tests similar to that carried out by Moscow.