The announcement by the United States that it has deployed a space weapon in Earth's orbit has raised questions about what weaponry is actually in space, and what role it could play in efforts by great powers to dominate that arena. Washington has given away little in its announcement.
Secretary of the Air Force Troy Meink said the "on orbit" weapon was necessary to safeguard US forces against hostile enemy action, but gave no details about the weapon's capabilities or when it was put into orbit. So what could this weapon be, and what is the wider picture like for military developments in space?
Who else could have similar weaponry? Space has been a militarised domain since the start of the space age - in the late 1960s, the Soviet Union deployed weapons up there.
The Istrebitel Sputnikov (IS; Satellite Destroyer) programme was made up of satellites that were designed to release projectiles that detonated, releasing shrapnel into the path of another (usually American) satellite. Nowadays, advanced militaries deploy satellites in space for a range of purposes, including reconnaissance, secure communications, detecting missile launches and providing precise location information for targeted strikes.
As warfare becomes more technologically advanced, analysts expect the use of military hardware in space to increase. Dr Bleddyn Bowen, an associate fellow in military sciences at the Royal United Services Institute and associate professor in astropolitics at Durham University, said he was only able to hazard a guess about the weapon announced by the US."
I would expect there to be some kind of electronic warfare or radio-jamming platform, possibly, this would be a non-destructive kind of anti-satellite weapon," he told BBC Radio 4's Today programme. Such weaponry already exists on Earth and can disrupt satellite communications, he said.
" If you take out the radio links then your satellite is very useless." Bowen also would not rule out a riskier and more disruptive type of weaponry, which could create debris and destruction."
Less likely would be a kinetic kill vehicle of some sort, so a vehicle that would release a projectile that could ram into a satellite and destroy it," he said. A type of "close inspection and grappling satellite would be another possibility as well."
But while the weapon placed in orbit may be unusual, the US - and indeed its Russian and Chinese rivals - have had weapons that can be pointed and shot into space for some time. In a later BBC interview, Bowen was dismissive of China's reaction to the US announcement which warned against an arms race in space, describing it as "the pot calling the kettle black"."
